| 1. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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Relapsing polychondritis : A rare disease with varying symptoms
- 2004
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420. ; 82:4, s. 472-475
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Relapsing polychondritis (RPC) is a rare systemic disease affecting primarily cartilaginous and proteoglycan-rich structures. It is a potentially fatal disease with unknown aetiology. There are no specific tests for RPC. The diagnosis is dependant on clinical criteria, which include chondritis of both auricles, non-erosive inflammatory polyarthritis, nasal chondritis, ocular inflammation, respiratory tract chondritis and cochlear and/or vestibular damage. Ocular symptoms will occur in approximately 60% of RPC patients. As an example, a patient with signs of RPC is described. Methods/Result: A 30-year-old woman was referred to our department for evaluation of a central corneal ulcer in the left eye. She had a history of recurrent pain in both her auricles and was also found to have a nasal septum perforation. Relapsing polychondritis was suspected. Conclusion: Non-healing corneal ulcers should alert the ophthalmologist to look for unusual reasons for this condition. RPC is one possible cause.
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| 2. |
- Ali, Zaheer, et al.
(författare)
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Intussusceptive Vascular Remodeling Precedes Pathological Neovascularization
- 2019
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Ingår i: Arteriosclerosis, Thrombosis and Vascular Biology. - : Lippincott Williams & Wilkins. - 1079-5642 .- 1524-4636. ; 39:7, s. 1402-1418
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Tidskriftsartikel (refereegranskat)abstract
- Objective—Pathological neovascularization is crucial for progression and morbidity of serious diseases such as cancer, diabetic retinopathy, and age-related macular degeneration. While mechanisms of ongoing pathological neovascularization have been extensively studied, the initiating pathological vascular remodeling (PVR) events, which precede neovascularization remains poorly understood. Here, we identify novel molecular and cellular mechanisms of preneovascular PVR, by using the adult choriocapillaris as a model.Approach and Results—Using hypoxia or forced overexpression of VEGF (vascular endothelial growth factor) in the subretinal space to induce PVR in zebrafish and rats respectively, and by analyzing choriocapillaris membranes adjacent to choroidal neovascular lesions from age-related macular degeneration patients, we show that the choriocapillaris undergo robust induction of vascular intussusception and permeability at preneovascular stages of PVR. This PVR response included endothelial cell proliferation, formation of endothelial luminal processes, extensive vesiculation and thickening of the endothelium, degradation of collagen fibers, and splitting of existing extravascular columns. RNA-sequencing established a role for endothelial tight junction disruption, cytoskeletal remodeling, vesicle- and cilium biogenesis in this process. Mechanistically, using genetic gain- and loss-of-function zebrafish models and analysis of primary human choriocapillaris endothelial cells, we determined that HIF (hypoxia-induced factor)-1α-VEGF-A-VEGFR2 signaling was important for hypoxia-induced PVR.Conclusions—Our findings reveal that PVR involving intussusception and splitting of extravascular columns, endothelial proliferation, vesiculation, fenestration, and thickening is induced before neovascularization, suggesting that identifying and targeting these processes may prevent development of advanced neovascular disease in the future.Visual Overview—An online visual overview is available for this article.
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| 3. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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An in Vivo Method for Visualizing Flow Dynamics of Cells within Corneal Lymphatics
- 2013
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Ingår i: Lymphatic Research and Biology. - : Mary Ann Liebert. - 1539-6851 .- 1557-8585. ; 11:2, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- Background: Monitoring the trafficking of specific cell populations within lymphatics could improve our understanding of processes such as transplant rejection and cancer metastasis. Current methods, however, lack appropriate image resolution for single-cell analysis or are incompatible with in vivo and longitudinal monitoring of lymphatics in their native state. We therefore sought to achieve high-resolution live imaging of the dynamic behavior of cells within lymph vessels in the rat cornea.Methods/Results: Inflammatory angiogenesis was induced by suture placement in corneas of Wistar rats. Pre- and up to 3 weeks post-induction, corneas were noninvasively examined by laser-scanning in vivo corneal confocal microscopy (IVCM) using only endogenous contrast. Lymph vessels and the cells harbored therein were documented by still images, real-time video, and 3D confocal stack reconstruction of live tissue. In vivo, conjunctival and corneal lymphatics were morphologically distinct, those with corneal location being one-quarter the diameter of those in the conjunctiva (p<0.001). Cells were recruited to initially empty pre-existing lymph vessels during the first day of inflammation and maintained a dense occupation of vessels for up to 7 days. A diverse population of cells (diameter range: 1.5–27.5 μm) with varying morphology was observed, and exhibited variable flow patterns and were transported singly and in clusters of at least 2–9 adherent cells.Conclusions: The in vivo microscopic technique presented enables lymph vessels and cell trafficking to be studied in high resolution in a minimally-perturbed physiologic milieu.
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| 4. |
- Bourghardt Peebo, Beatrice, 1968-
(författare)
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Angiogenesis from a new perspective
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Angiogenesis is the emergence of new blood and lymph vessels from existing ones. In the pathologic form it contributes to the onset and progression of numerous different human disorders such as cancer, inflammation, atherosclerosis and blinding eye diseases. There exist a number of models to study angiogenesis, both in vitro and in vivo, but there is no single perfect model so far. Consequently there is a need to develop new angiogenesis assays for evaluating blood and lymph vessel behaviour in different physiologic settings.The aim of this thesis was to gain insight into in vivo angiogenesis introducing a new technique in an inflammatory corneal model. The method involved in vivo examination of the cornea and subsequent comparison of in vivo findings with ex vivo immunohistochemical analysis of the same tissue samples. An existing suture model for inflammatory angiogenesis in the cornea was modified for in vivo observations with a clinically-approved corneal confocal microscope.In this thesis, corneal lymph vessels were characterized for the first time in vivo and findings from the experimental bench could be applied in a clinical setting, where presumed lymphatics were observed in a corneal transplant patient with rejection. Furthermore, the technique was extended to investigate time-lapse processes in sprouting and regressing capillaries, and led to a number of new observations. CD11b+ myeloid cells constitute the first bulk of infiltrating inflammatory cells and contribute to inflammatory sprouting and regression in numerous ways including pre-patterning of the corneal stroma and guiding of capillary sprouts. Newly formed hemangiogenic sprouts are perfused with a slow-moving fluid and have a lumen. In blood vessel regression, capillary remodeling occurred by abandonment of sprout tips in close association with macrophages and vascular loops formed by presumed intussusceptive angiogenesis. In addition, a network of pericyte- and endothelium-free basement membrane tubes was formed after desertion or degradation of vascular endothelium in former corneal capillaries.In conclusion, we introduce a new in vivo technique for investigating angiogenesis in a corneal model were in vivo findings can be interpreted with ex vivo definitions of specific cell types by immunohistochemistry. Findings from pre-clinical experiments have been possible to apply in a clinical setting when examining patients with corneal pathology.
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| 5. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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Cellular level characterization of capillary regression in inflammatory angiogenesis using an in vivo corneal model
- 2011
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Ingår i: Angiogenesis. - : Springer Verlag (Germany). - 0969-6970 .- 1573-7209. ; 14:3, s. 393-405
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we introduce a technique for repeated, microscopic observation of single regressing capillaries in vivo in inflamed murine corneas. Natural capillary regression was initiated by removal of inflammatory stimulus during an active pro-angiogenic phase, while the additional impact of anti-angiogenic treatment with triamcinolone or bevazicumab was investigated. Capillaries regressed naturally within 1 week and treatments did not further enhance the natural regression. Morphologically, early-phase regression was characterized by significant lumen narrowing and a significant reduction in CD11b+ myeloid cell infiltration of the extracellular matrix. By 1 week, vascular remodeling occurred concomitant with CD11b+CD68+KiM2R+ mature macrophage localization on capillary walls. Empty conduits without blood flow, positive for collagen IV and devoid of vascular endothelium and pericytes, were apparent in vivo and by 3 weeks were more numerous than perfused capillaries. By 3 weeks, macrophages aggregated around remaining perfused capillaries and were observed in apposition with degrading capillary segments. Abrupt termination of capillary sprouting in our regression model further revealed vascular endothelial abandonment of sprout tips and perfused capillary loop formation within a single angiogenic sprout, possibly as an intussusceptive response to cessation of the stimulus. Finally, we observed lumen constriction and macrophage localization on capillary walls in vivo in a clinical case of corneal capillary regression that paralleled findings in our murine model.
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| 6. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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Cellular-Level Characterization of Lymph Vessels in Live, Unlabeled Corneas by In Vivo Confocal Microscopy
- 2010
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Ingår i: Investigative Ophthalmology and Visual Science. - Rockville, MD, United States : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 51:2, s. 830-835
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To determine whether in vivo confocal microscopy (IVCM) of the cornea can be used for the label-free detection and monitoring of lymph vessels in live corneas.METHODS. Parallel corneal hemangiogenesis and lymphangiogenesis was induced by the placement of a single suture in one cornea of male Wistar rats. Fourteen days after suture placement and under general anesthesia, laser-scanning IVCM was performed in the vascularized region. Corneas were subsequently excised for flat-mount double immunofluorescence with a pan-endothelial marker (PECAM-1/CD31) and a lymphatic endothelial specific marker (LYVE-1). Using the suture area and prominent blood vessels as points of reference, the identical microscopic region was located in both fluorescent and archived in vivo images. Additionally, vessel diameter, lumen contrast, and cell diameter and velocity within vessels were quantified from in vivo images.RESULTS. Comparison of identical corneal regions in fluorescence and in vivo revealed prominent CD31(+)/LYVE-1(3+) lymph vessels that were visible in vivo. In vivo, corneal lymph vessels were located in the vascularized area in the same focal plane as blood vessels but had a darker lumen (P andlt; 0.001) sparsely populated by highly reflective cells with diameters similar to those of leukocytes in blood vessels (P = 0.61). Cell velocity in lymph vessels was significantly reduced compared with blood particle velocity (P andlt; 0.001). Morphologic characteristics enabled subsequent identification of corneal lymphatics in live, vascularized rat corneas before immunofluorescence labeling.CONCLUSIONS. IVCM enabled the nondestructive, label-free, in vivo detection of corneal lymphatics. IVCM provides the possibility of observing lymphatic activity in the same live corneas longitudinally and, as a clinical instrument, of monitoring corneal lymphatics in live human subjects.
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| 7. |
- Bourghardt Peebo, Beatrice, 1968-, et al.
(författare)
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Expression of the focal adhesion protein PINCH in normal and alkali-injured corneas and the role of PMNs
- 2007
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907 .- 1600-0420. ; 85:4, s. 395-400
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the role of particularly interesting new cysteine-histidine-rich protein (PINCH) in corneal wound healing and early neovascularization and to assess the influence of granulocytes. Methods: A standardized corneal alkali wound was inflicted under general anaesthesia to the right eye of 14 New Zealand White rabbits. Seven of the rabbits received i.v. 5 mg/kg fucoidin every 2 hours to prevent granulocytes from entering the wound area. After 36 hours, the rabbits were killed, the corneas excised, fixed in 4% formaldehyde and embedded in paraffin. The sections were double-stained with antibodies against PINCH and with haematoxylin. Results: In the normal cornea and limbus, PINCH was weakly expressed in the corneal epithelium and in a wedge of the conjunctival stroma. In the wounded corneas, PINCH expression was seen in the frontline of repopulating endothelial and epithelial cells, and in active keratocytes. The vascular endothelium and the granulocytes expressed PINCH, as did the conjunctival epithelium. In the fucoidin-treated rabbits, PINCH expression was markedly reduced. The vascular endothelial cells and the few granulocytes did not express PINCH in these rabbits. Conclusions: PINCH is only slightly expressed in the normal cornea. A corneal wound induces PINCH expression in the repopulating cells, in the vascular endothelial cells of the limbus, in the limbal epithelium and in the granulocytes. Exclusion of granulocytes reduces expression of PINCH and there is no expression at all in the vascular endothelium. © 2007 The Authors Journal compilation 2007 Acta Ophthalmol Scand.
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| 8. |
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| 9. |
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| 10. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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Time-Lapse In Vivo Imaging of Corneal Angiogenesis: The Role of Inflammatory Cells in Capillary Sprouting
- 2011
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Ingår i: Investigative Ophthalmology and Visual Science. - : Research in Vision and Opthalmology. - 0146-0404 .- 1552-5783. ; 52:6, s. 3060-3068
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To elucidate the temporal sequence of events leading to new capillary sprouting in inflammatory corneal angiogenesis. METHODS. Angiogenesis was induced by corneal suture placement in Wistar rats. The inflamed region was examined by time-lapse in vivo confocal microscopy for up to 7 days. At 6 and 12 hours and 1, 2, 4, and 7 days, corneas were excised for flat mount immunofluorescence with primary antibodies for CD31, CD34, CD45, CD11b, CD11c, Ki-M2R, NG2, and alpha-SMA. From days 0 to 4, the in vivo extravasation and expansion characteristics of single limbal vessels were quantified. RESULTS. Starting hours after induction and peaking at day 1, CD45(+)CD11b(+) myeloid cells extravasated from limbal vessels and formed endothelium-free tunnels within the stroma en route to the inflammatory stimulus. Limbal vessel diameter tripled on days 2 to 3 as vascular buds emerged and transformed into perfused capillary sprouts less than 1 day later. A subset of spindle-shaped CD11b(+) myeloid-lineage cells, but not dendritic cells or mature macrophages, appeared to directly facilitate further capillary sprout growth. These cells incorporated into vascular endothelium near the sprout tip, co-expressing endothelial marker CD31. Sprouts had perfusion characteristics distinct from feeder vessels and many sprout tips were open-ended. CONCLUSIONS. Time-lapse in vivo corneal confocal microscopy can be used to track a temporal sequence of events in corneal angiogenesis. The technique has revealed potential roles for myeloid cells in promoting vessel sprouting in an inflammatory corneal setting.
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| 11. |
- Bourghardt Peebo, Beatrice, et al.
(författare)
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Transient Anterior Corneal Deposits in a Human Immunodeficiency Virus-Positive Patient
- 2010
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Ingår i: CORNEA. - : Lippincott Williams and Wilkins. - 0277-3740. ; 29:11, s. 1323-1327
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To report findings of pigmented anterior corneal deposits in a human immunodeficiency virus-positive patient. Methods: Case report. A 49-year-old human immunodeficiency virus-positive patient was examined after the appearance of pigmented corneal deposits. Slit-lamp biomicroscopy, fundus photography, and laser-scanning in vivo confocal microscopy were performed to visually document the ocular condition. Results: The patient had a history of Mycobacterium avium infection and was suspected to have recovery uveitis from a cytomegalovirus infection. Small, rounded, light brown-colored deposits were distributed across the anterior cornea from limbus to limbus, bilaterally. In vivo confocal microscopy revealed the deposits to be confined to the basal epithelium and Bowman layer, whereas the posterior stroma, Descemet membrane, and the endothelium appeared normal. Systemic steroid treatment was administered, and 2 weeks later, the deposits had vanished on slit-lamp examination, whereas remnants were observed at the microscopic level. Conclusions: The deposits were unusual for their anterior corneal location and pancorneal distribution. The response to systemic steroid treatment remains unexplained and illustrates the complexity of the underlying conditions, their treatment, and the associated pathways of ocular manifestation.
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| 12. |
- Frennesson, Christina, et al.
(författare)
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Significant improvements in near vision, reading speed, central visual field and related quality of life after ranibizumab treatment of wet age-related macular degeneration
- 2010
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Ingår i: ACTA OPHTHALMOLOGICA. - : Blackwell Publishing Ltd. - 1755-375X .- 1755-3768. ; 88:4, s. 420-425
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the effects on near visual acuity, reading speed, central visual field and related quality of life of ranibizumab treatment of wet age-related macular degeneration (AMD). Methods: The study was a prospective, non-comparative consecutive case series, followed for 3 months and investigator-driven. Thirty eyes of 30 patients with wet AMD were included, mean age 75 years (range 69-95 years). In addition to a full ophthalmological examination - including best-corrected visual acuity (BCVA; Early Treatment Diabetic Research Study chart), fundus biomicroscopy, fundus photography, fluorescein angiography, indocyanine green angiography (occult cases) and ocular coherence tomography - near visual acuity, reading speed, central visual field and quality of life for related activities were also investigated at baseline and at 3 months after ranibizumab treatment. Results: Mean BCVA increased from 62 +/- 11 to 66 +/- 14 letters at 3 months (7%; p = 0.018). Near vision improved from 9 +/- 5 to 6 +/- 3 points (33%; p = 0.0006) and reading speed increased from 59 +/- 40 to 85 +/- 50 words/min (44%; p andlt; 0.0001). The mean deviation from normal of the visual field improved from -9 +/- 7 to -6 +/- 5 dB (33%; p andlt; 0.0001). Quality of life improved for distance activities from 54 +/- 28 to 63 +/- 28 points (17%; p andlt; 0.0001) but significantly (p = 0.024) more for near activities, from 49 +/- 26 to 63 +/- 26 points (29%; p andlt; 0.0001). Reading newspaper text in the group in which the better eye was treated showed the highest increase in quality of life score of all: 116%. Conclusion: The increase in BCVA after ranibizumab treatment is well established. The present study also showed significant improvements in other important visual qualities, such as near visual acuity, reading speed, central visual field and several activities influencing quality of life. The improvement was greater for near activities than for distance activities. Therefore, the beneficial effects of ranibizumab treatment shown here are more extensive than those reported previously.
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| 13. |
- Heintz, Emelie, 1981-, et al.
(författare)
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Health-related quality of life profiles of patients with diabetic retinopathy
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: There are various instruments for estimating health-related quality of life (HRQoL) in patients with diabetic retinopathy (DR). However, if the results are to be compared with those for other diseases, it is essential to use measures that are applicable to all disease areas. The aim of this study was to explore the HRQoL profiles of patients with DR using two generic multi-attribute instruments, the Health State Utilities Index Mark 3 (HUI-3) and the EQ-5D questionnaire, and to investigate these questionnaires’ sensitivity to differences in HRQoL due to DR. Methods: The study population comprised 166 Swedish diabetes patients diagnosed with DR at different severities. Patients were interviewed over the telephone using HUI-3 and EQ-5D. The vision-specific National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25) was also included, to give an empirical framework for the results of the generic instruments. Linear and logistic regression models were used to adjust for possible confounders. Results: Patients with vision impairment (VI) reported lower scores in Vision, Ambulation, and Pain in HUI-3 and more problems with Usual activities and Anxiety/depression in EQ-5D. However, even though NEI VFQ-25 showed a negative association between DR severity and Mental health and Near activities, neither EQ-5D nor HUI-3 identified a negative relationship between DR severity and HRQoL. Conclusion: The generic instruments show lowered HRQoL for patients with VI in various dimensions but were not sensitive to decrements related to the diagnosis of DR alone. The questionnaire of HUI-3 was more sensitive than EQ-5D to differences in HRQoL due to DR-related VI.
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| 14. |
- Heintz, Emelie, et al.
(författare)
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Prevalence and healthcare costs of diabetic retinopathy : a population-based register study in Sweden
- 2010
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 53:10, s. 2147-2154
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesisThe aim of the present study was to estimate the prevalence and healthcare costs of diabetic retinopathy (DR).MethodsThis population-based study included all residents (n = 251,386) in the catchment area of the eye clinic of Linköping University Hospital, Sweden. Among patients with diabetes (n = 12,026), those with and without DR were identified through register data from both the Care Data Warehouse in Östergötland, an administrative healthcare register, and the Swedish National Diabetes Register. Healthcare cost data were elicited by record linkage of these two registers to data for the year 2008 in the Cost Per Patient Database developed by Östergötland County Council.ResultsThe prevalence of any DR was 41.8% (95% CI 38.9–44.6) for patients with type 1 diabetes and 27.9% (27.1–28.7) for patients with type 2 diabetes. Sight-threatening DR was present in 12.1% (10.2–14.0) and 5.0% (4.6–5.4) of the type 1 and type 2 diabetes populations respectively. The annual average healthcare cost of any DR was €72 (€53–91). Stratified into background retinopathy, proliferative DR, maculopathy, and the last two conditions combined, the costs were €26 (€10–42), €257 (€155–359), €216 (€113–318) and €433 (€232–635) respectively. The annual cost for DR was €106 000 per 100,000 inhabitants.ConclusionsThis study presents new information on the prevalence and costs of DR. Approximately one-third of patients with diabetes have some form of DR. Average healthcare costs increase considerably with the severity of DR, which suggests that preventing progression of DR may lower healthcare costs.
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| 15. |
- Heintz, Emelie, et al.
(författare)
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QALY weights for diabetic retinopathy : a comparison of health state valuations with HUI-3, EQ-5D, EQ-VAS, and TTO.
- 2012
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Ingår i: Value in Health. - : Elsevier. - 1098-3015 .- 1524-4733. ; 15:3, s. 475-484
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To estimate quality-adjusted life-year weights for patients with diabetic retinopathy by using various methods and to investigate the empirical validity of the different measures.Methods: The study population comprised 152 patients with diabetes in Östergötland County, Sweden. Participants were interviewed by telephone by using the time trade-off (TTO) method and a visual analogue scale (EQ-VAS) (direct valuations) as well as the EuroQol five-dimensional questionnaire (EQ-5D) and the health utilities index mark 3 (HUI-3) (indirect valuations). The quality-adjusted life-year weights were adjusted for potential confounders by using analysis of covariance. The empirical validity of the measures was examined by testing their ability to detect hypothetical differences between severity levels of diabetic retinopathy and by investigating the correlation between the measures and the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25).Results: All measures detected significant differences in scores between patient groups classified according to visual impairment in the better eye (analysis of covariance, P < 0.05), but only HUI-3 and EQ-VAS detected significant differences between patient groups classified according to visual impairment or pathological progression in the worse eye. HUI-3 recorded a difference of 0.43 in values between normal vision and blindness in the better eye, which was more than twice the differences captured by the other measures (0.15–0.20). In addition, HUI-3 showed the highest correlation with NEI VFQ-25 (r = 0.54; P < 0.001).Conclusions: In cost-utility analyses, the choice of quality-adjusted life-year measure may affect whether an intervention is considered cost-effective. Furthermore, if decisions are to be based on values from the general public, HUI-3 can be recommended for cost-utility analyses of interventions directed at diabetic retinopathy.
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| 16. |
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| 17. |
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| 18. |
- Lagali, Neil S, 1973-, et al.
(författare)
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Reduced Corneal Nerve Fiber Density in Type 2 Diabetes by Wide-Area Mosaic Analysis
- 2017
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Ingår i: Investigative Ophthalmology and Visual Science. - : The Assocation for Research in Vision and Ophthalmology. - 0146-0404 .- 1552-5783. ; 58:14, s. 6318-6327
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To determine if corneal subbasal nerve plexus (SBP) parameters derived from wide-area depth-corrected mosaic images are associated with type 2 diabetes.METHODS. One hundred sixty-three mosaics were produced from eyes of 82 subjects by laser-scanning in vivo confocal microscopy (IVCM). Subjects were of the same age, without (43 subjects) or with type 2 diabetes (39 subjects). Mosaic corneal nerve fiber length density (mCNFL) and apical whorl corneal nerve fiber length density (wCNFL) were quantified and related to the presence and duration of diabetes (short duration < 10 years and long duration ≥10 years).RESULTS. In mosaics with a mean size of 6 mm2 in subjects aged 69.1 ± 1.2 years, mCNFL in type 2 diabetes was reduced relative to nondiabetic subjects (13.1 ± 4.2 vs. 15.0 ± 3.2 mm/mm2, P = 0.018). Also reduced relative to nondiabetic subjects was mCNFL in both short-duration (14.0 ± 4.0 mm/mm2, 3.2 ± 3.9 years since diagnosis) and long-duration diabetes (12.7 ± 4.2 mm/mm2, 15.4 ± 4.2 years since diagnosis; ANOVA P =0.023). Lower mCNFL was associated with presence of diabetes (P =0.032) and increased hemoglobin A1c (HbA1c) levels (P = 0.047). By contrast, wCNFL was unaffected by diabetes or HbA1c (P > 0.05). Global SBP patterns revealed marked degeneration of secondary nerve fiber branches outside the whorl region in long-duration diabetes.CONCLUSIONS. Wide-area mosaic images provide reference values for mCNFL and wCNFL and reveal a progressive degeneration of the SBP with increasing duration of type 2 diabetes.
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| 19. |
- Lagali, Neil, et al.
(författare)
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Wide-field corneal subbasal nerve plexus mosaics in age-controlled healthy and type 2 diabetes populations
- 2018
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Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- A dense nerve plexus in the clear outer window of the eye, the cornea, can be imaged in vivo to enable non-invasive monitoring of peripheral nerve degeneration in diabetes. However, a limited field of view of corneal nerves, operator-dependent image quality, and subjective image sampling methods have led to difficulty in establishing robust diagnostic measures relating to the progression of diabetes and its complications. Here, we use machine-based algorithms to provide wide-area mosaics of the corneas subbasal nerve plexus (SBP) also accounting for depth (axial) fluctuation of the plexus. Degradation of the SBP with age has been mitigated as a confounding factor by providing a dataset comprising healthy and type 2 diabetes subjects of the same age. To maximize reuse, the dataset includes bilateral eye data, associated clinical parameters, and machine-generated SBP nerve density values obtained through automatic segmentation and nerve tracing algorithms. The dataset can be used to examine nerve degradation patterns to develop tools to non-invasively monitor diabetes progression while avoiding narrow-field imaging and image selection biases.
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| 20. |
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| 21. |
- Mirabelli, Pierfrancesco, et al.
(författare)
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Early effects of dexamethasone and anti-VEGF therapy in an inflammatory corneal neovascularization model
- 2014
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Ingår i: Experimental Eye Research. - : Elsevier. - 0014-4835 .- 1096-0007. ; 125, s. 118-127
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Tidskriftsartikel (refereegranskat)abstract
- Inflammatory angiogenesis is the pathogenic mechanism of various sight-threatening eye diseases, among them corneal neovascularization. Current treatment options include steroids which have undesirable side effects, or anti-VEGF which has only limited efficacy. In an inflammatory environment, however, angiogenesis can be stimulated by numerous factors not directly targeted by anti-VEGF therapy. The aim of this study was to induce corneal inflammation leading to angiogenesis, and investigate the early, differential effects of steroid and anti-VEGF therapy at the cellular, tissue, and gene expression levels. Fifty-two Wistar rats received a single intrastromal corneal suture to induce a controlled inflammatory angiogenic response. Rats were subsequently treated with dexamethasone, rat specific anti-VEGF, or goat IgG (control), topically 4 times daily for 7 days. In vivo confocal microscopy of the cornea was performed longitudinally from 5 h up to 7 d to investigate morphology at the cellular and tissue-level. In vivo photographic vessel analysis and immunohistochemistry were also performed. RT-PCR for VEGF-A, FGF-2, IL-6, TNF-alpha, CXCL2, CCL2, CCL3 and DLL4 was performed at 24 h, and for VEGF-A, IL-6, TNF-alpha, FGF-2, CXCL2, CCL2, and CCL3 at 7 days. Early infiltration of CD11b + myeloid cells into the cornea at 5 h post-suture was delayed by both treatments relative to controls; however neither treatment was able to suppress accumulation of myeloid cells at day 2 or 7. Limbal vessel dilation was inhibited at 5 h by both treatments, but only dexamethasone showed sustained effect until day 2. Early macrophage recruitment was also suppressed by dexamethasone (but not by anti-VEGF) until day 2. Dexamethasone furthermore suppressed corneal neovascularization at day 7 by over 90%, whereas suppression by anti-VEGF was 14%. Despite differential suppression of vessel dilation, macrophage recruitment, and vascular invasion, anti-VEGF and dexamethasone both down-regulated VEGF-A and IL-6 expression at 24 h with sustained effect to 7 d. They also both down regulated FGF-2 and TNF-alpha at 24 h and CCL2 at 7 d. In conclusion, anti-angiogenic treatments influence early, pre-angiogenic tissue activity such as limbal vessel dilation, inflammatory cell infiltration of the stroma, and macrophage recruitment. Importantly, the differential effects of steroids and anti-VEGF treatment in suppressing neovascular growth could not be attributed to differential inhibition of several major angiogenic and inflammatory factors in the early pre-sprouting phase, including IL-6, VEGF-A, FGF-2, TNF-alpha, CCL2, CCL3, CXCL2, or DLL4.
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| 22. |
- Mirabelli, Pierfrancesco, et al.
(författare)
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Genome-wide expression differences in anti-Vegf and dexamethasone treatment of inflammatory angiogenesis in the rat cornea
- 2017
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Angiogenesis as a pathological process in the eye can lead to blindness. In the cornea, suppression of angiogenesis by anti-VEGF treatment is only partially effective while steroids, although effective in treating inflammation and angiogenesis, have broad activity leading to undesirable side effects. In this study, genome-wide expression was investigated in a suture-induced corneal neovascularization model in rats, to investigate factors differentially targeted by dexamethasone and anti-Vegf. Topical treatment with either rat-specific anti-Vegf, dexamethasone, or normal goat IgG (sham) was given to sutured corneas for 48 hours, after which in vivo imaging, tissue processing for RNA microarray, and immunofluorescence were performed. Dexamethasone suppressed limbal vasodilation (P amp;lt; 0.01) and genes in PI3K-Akt, focal adhesion, and chemokine signaling pathways more effectively than anti-Vegf. The most differentially expressed genes were confirmed by immunofluorescence, qRTPCR and Western blot. Strong suppression of Reg3g and the inflammatory chemokines Ccl2 and Cxcl5 and activation of classical complement pathway factors C1r, C1s, C2, and C3 occurred with dexamethasone treatment, effects absent with anti-Vegf treatment. The genome-wide results obtained in this study provide numerous potential targets for specific blockade of inflammation and angiogenesis in the cornea not addressed by anti-Vegf treatment, as possible alternatives to broad-acting immunosuppressive therapy.
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| 23. |
- Mirabelli, Pierfrancesco
(författare)
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Inhibitors of corneal inflammation and angiogenesis : Prospectives and challenges
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pathologic angiogenesis is involved in cancer and several blinding conditions such as wet age-related macular degeneration, proliferative retinopathies and corneal neovascularization.In these dieseases, the angiogenic triggers are hypoxia and inflammation, and both involve the main angiogenic mediator, which is Vascular Endothelial Growth Factor (VEGF). Among available treatments, anti-VEGF often shows limited or temporary efficacy, while steroids are potentially responsible for many side-effects. This thesis presents a series of linked studies aimed at elucidating the early pathologic changes leading to inflammation and corneal neovascularization, and how various treatments affect this process. In this thesis, anti-inflammatory and anti-angiogenic treatments are applied in corneal neovascularization models, to identify VEGF-independent pathways and other novel factors as future therapy targets, as well as to investigate the endogenous modulation of angiogenesis.A model of experimental neovascularization in the rat cornea was used as main model, where the neovascular response is triggered by a surgical suture placed into the cornea. Investigational treatments (anti-Vegf, dexamethasone, IMD0354, Gap27, or control substances) were then given topically, with the exception of IMD0354, which was given systemically. The effects in the cornea were studied in vivo with slit lamp photography to assess and quantify macroscopic vessel growth and using in vivo confocal microscopy (IVCM) to study cell infiltration and limbal vessel dilation and detect microscopic vessel sprouts; these examinations were performed longitudinally. Genomic analysis with RNA microarray, selected gene expression with q-RT-PCR, and selected protein expression in tissue (immunohistochemistry, immunofluorescence, Western blot) were performed at different time-points. Moreover, other experiments on cell cultures (HUVEC and HCEC), organ cultures (human corneas), ex vivo models (aortic rings) and in vivo studies (zebrafish vasculogenesis) were performed.Dexamethasone suppressed limbal vasodilation and corneal neovascularization more than anti-Vegf, despite no difference in inflammatory cell infiltration into the cornea. Five-hundred eleven fewer genes were differentially expressed in dexamethasone-treated corneas relative to naïve corneas, compared to anti-Vegf. Among them, several major pro-angiogenic and pro-inflammatory factors and chemokines were suppressed only by dexamethasone and represent novel candidate factors to target in order to improve anti-VEGF treatment. On the other hand, selective inhibition of a single inflammatory pathway (NF-κB), despite showing similar early effects as dexamethasone in suppressing tissue inflammation, was not effective enough to suppress new vessel growth. The same factors suppressed by dexamethasone are also inhibited in endogenous modulation of angiogenesis. Surprisingly, dexamethasone activated several complement factors, which could possibly be beneficial in the anti-angiogenic response.In a different therapeutic approach, promoting cell migration to accelerate epithelial wound closure similarly was not sufficient to avoid inflammation and angiogenesis in the cornea.In conclusion, new and more effective treatments are needed for corneal inflammation and neovascularization with fewer side-effects. In this thesis, several novel factors and mechanisms related to inflammation are identified, factors that are not addressed by anti-Vegf therapy, and therefore represent interesting objects for further study, as they have the potential to be targets for adjuvant therapy. Specific anti-inflammatory treatment as well as therapeutic activation of endogenous regulatory pathways, and potentially complement modulation, might represent new strategies to improve anti-angiogenic therapy, but when used alone they do not seem to avoid corneal neovascularization.
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| 24. |
- Mukwaya, Anthony, et al.
(författare)
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A microarray whole-genome gene expression dataset in a rat model of inflammatory corneal angiogenesis
- 2016
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- In angiogenesis with concurrent inflammation, many pathways are activated, some linked to VEGF and others largely VEGF-independent. Pathways involving inflammatory mediators, chemokines, and micro-RNAs may play important roles in maintaining a pro-angiogenic environment or mediating angiogenic regression. Here, we describe a gene expression dataset to facilitate exploration of pro-angiogenic, pro-inflammatory, and remodelling/normalization-associated genes during both an active capillary sprouting phase, and in the restoration of an avascular phenotype. The dataset was generated by microarray analysis of the whole transcriptome in a rat model of suture-induced inflammatory corneal neovascularisation. Regions of active capillary sprout growth or regression in the cornea were harvested and total RNA extracted from four biological replicates per group. High quality RNA was obtained for gene expression analysis using microarrays. Fold change of selected genes was validated by qPCR, and protein expression was evaluated by immunohistochemistry. We provide a gene expression dataset that may be re-used to investigate corneal neovascularisation, and may also have implications in other contexts of inflammation-mediated angiogenesis.
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| 25. |
- Mukwaya, Anthony, et al.
(författare)
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Factors regulating capillary remodeling in a reversible model of inflammatory corneal angiogenesis
- 2016
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 6, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Newly formed microcapillary networks arising in adult organisms by angiogenic and inflammatory stimuli contribute to pathologies such as corneal and retinal blindness, tumor growth, and metastasis. Therapeutic inhibition of pathologic angiogenesis has focused on targeting the VEGF pathway, while comparatively little attention has been given to remodeling of the new microcapillaries into a stabilized, functional, and persistent vascular network. Here, we used a novel reversible model of inflammatory angiogenesis in the rat cornea to investigate endogenous factors rapidly invoked to remodel, normalize and regress microcapillaries as part of the natural response to regain corneal avascularity. Rapid reversal of an inflammatory angiogenic stimulus suppressed granulocytic activity, enhanced recruitment of remodelling macrophages, induced capillary intussusception, and enriched pathways and processes involving immune cells, chemokines, morphogenesis, axonal guidance, and cell motility, adhesion, and cytoskeletal functions. Whole transcriptome gene expression analysis revealed suppression of numerous inflammatory and angiogenic factors and enhancement of endogenous inhibitors. Many of the identified genes function independently of VEGF and represent potentially new targets for molecular control of the critical process of microvascular remodeling and regression in the cornea.
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| 26. |
- Mukwaya, Anthony, et al.
(författare)
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Genome-wide expression datasets of anti-VEGF and dexamethasone treatment of angiogenesis in the rat cornea
- 2017
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Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Therapeutics against pathologic new blood vessel growth, particularly those targeting vascular endothelial growth factor (VEGF) are of enormous clinical interest. In the eye, where anti-VEGF agents are in widespread clinical use for treating retinal and corneal blindness, only partial or transient efficacy and resistance to anti-VEGF agents are among the major drawbacks. Conversely, corticosteroids have long been used in ophthalmology for their potency in suppressing inflammation and angiogenesis, but their broad biological activity can give rise to side effects such as glaucoma and cataract. To aid in the search for more targeted and effective anti-angiogenic therapies in the eye, we present here a dataset comparing gene expression changes in dexamethasone versus anti-Vegfa treatment of inflammation leading to angiogenesis in the rat cornea. Global gene expression analysis with GeneChip Rat 230 2.0 microarrays was conducted and the metadata submitted to Expression Omnibus repository. Here, we present a high-quality validated dataset enabling genome-wide comparison of genes differentially targeted by dexamethasone and anti-Vegf treatments, to identify potential alternative therapeutic targets for evaluation.
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| 27. |
- Mukwaya, Anthonny, et al.
(författare)
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MicroRNAs in the cornea: Role and implications for treatment of corneal neovascularization
- 2019
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Ingår i: OCULAR SURFACE. - : ELSEVIER. - 1542-0124. ; 17:3, s. 400-411
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Forskningsöversikt (refereegranskat)abstract
- With no safe and efficient approved therapy available for treating corneal neovascularization, the search for alternative and effective treatments is of great importance. Since the discovery of miRNAs as key regulators of gene expression, knowledge of their function in the eye has expanded continuously, facilitated by high throughput genomic tools such as microarrays and RNA sequencing. Recently, reports have emerged implicating miRNAs in pathological and developmental angiogenesis. This has led to the idea of targeting these regulatory molecules as a therapeutic approach for treating corneal neovascularization. With the growing volume of data generated from high throughput tools applied to study corneal neovascularization, we provide here a focused review of the known miRNAs related to corneal neovascularization, while presenting new experimental data and insights for future research and therapy development.
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| 28. |
- Mukwaya, Anthony
(författare)
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Regulation of inflammation and angiogenesis in the cornea
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Inflammation and angiogenesis, the growth of new blood vessels from pre-existing ones, are involved in tumor growth, ocular diseases and wound healing. In ocular angiogenesis, new pathological vessels grow into a specific eye tissue, leak fluid, and disrupt vision. The development of safe and effective therapies for ocular angiogenesis is of great importance for preventing blindness, given that current treatments have limited efficacy or are associated with undesirable side effects. The search for alternative treatment targets requires a deeper understanding of inflammation and how it can lead to angiogenesis in the eye in pathologic situations. This thesis provides new insights into the regulation of inflammation and angiogenesis, particularly at the gene expression and phenotypic levels, in different situations characterized by angiogenesis of the cornea, often called corneal neovascularization. For instance, specific genes and pathways are either endogenously activated or suppressed during active inflammation, wound healing, and during resolution of inflammation and angiogenesis, serving as potential targets to modulate the inflammatory and angiogenic response. In addition, as part of the healing response to restore corneal transparency, inflammation and angiogenesis subside with time in the cornea. In this context, LXR/RXR signaling was found to be activated in a time-dependent manner, to potentially regulate resolution of inflammation and angiogenesis. During regression of new angiogenic capillaries, ghost vessels and empty basement membrane sleeves are formed, which can persist in the cornea for a long time. Here, ghost vessels were found to facilitate subsequent revascularization of the cornea, while empty basement membrane sleeves did not revascularize. The revascularization response observed here was characterised by vasodilation, increased inflammatory cell infiltration and by sprouting at the front of the reperfused vessels. Importantly, reactive oxygen species and nitrous oxide signaling among other pro-inflammatory pathways were activated, and at the same time anti-inflammatory LXR/RXR signaling was inhibited. The interplay between activation and inhibition of these pathways highlights potential mechanisms that regulate corneal revascularization. When treating corneal neovascularization clinically, corticosteroids are in widespread use due to their effectiveness. To minimize the many undesirable side effects associated with corticosteroid use, however, identifying new and more selective agents is of great importance. Here, it was observed that corticosteroids not only suppressed pro-inflammatory chemokines and cytokines, but also activated the classical complement pathway. Classical complement may represent a candidate for further selective therapeutic manipulation to investigate its effect on treatment of corneal neovascularization.In summary, this thesis identifies genes, pathways, and phenotypic responses involved in sprouting and remodeling of corneal capillaries, highlights novel pathways and factors that may regulate inflammation and angiogenesis in the cornea, and provides insights into regulation of capillary regression and reactivation. Further investigation of these regulatory mechanisms may offer alternative and effective treatment targets for the treatment of corneal inflammation and angiogenesis.
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| 29. |
- Mukwaya, Anthonny, et al.
(författare)
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Repeat Corneal Neovascularization is Characterized by More Aggressive Inflammation and Vessel Invasion Than in the Initial Phase
- 2019
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Ingår i: Investigative Ophthalmology and Visual Science. - Rockville, MD, United States : Association for Research in Vision and Ophthalmology. - 0146-0404 .- 1552-5783. ; 60:8, s. 2990-3001
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Treatment of corneal neovascularization can lead to vessel regression and recovery of corneal transparency. Here, we examined the response of the cornea to a repeated stimulus after initial vessel regression comparing the second wave of neovascularization with the first.Methods: Corneal neovascularization was induced by surgical suture placement in the rat cornea for 7 days, followed by suture removal and a 30-day regression period. Corneas were then re-sutured and examined for an additional 4 days. Longitudinal slit-lamp imaging, in vivo confocal microscopy, and microarray analysis of global gene expression was conducted to assess the inflammatory and neovascularization response. Inhibitory effect of topical dexamethasone for repeat neovascularization was assessed.Results: After initial robust neovascularization, 30 days of regression resulted in the recovery of corneal transparency; however, a population of barely functional persistent vessels remained at the microscopic level. Upon re-stimulation, inflammatory cell invasion, persistent vessel dilation, vascular invasion, and gene expression of Vegfa, Il1β, Il6, Ccl2, Ccl3, and Cxcl2 all doubled relative to initial neovascularization. Repeat neovascularization occurred twice as rapidly as initially, with activation of nitric oxide and reactive oxygen species, matrix metalloproteinase, and leukocyte extravasation signaling pathways, and suppression of anti-inflammatory LXR/RXR signaling. While inhibiting initial neovascularization, a similar treatment course of dexamethasone did not suppress repeat neovascularization.Conclusions: Persistent vessels remaining after the initial resolution of neovascularization can rapidly reactivate to facilitate more aggressive inflammation and repeat neovascularization, highlighting the importance of achieving and confirming complete vessel regression after an initial episode of corneal neovascularization.
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| 30. |
- Mukwaya, Anthony, et al.
(författare)
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Revascularization after angiogenesis inhibition favors new sprouting over abandoned vessel reuse
- 2019
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Ingår i: Angiogenesis. - : Springer Netherlands. - 0969-6970 .- 1573-7209. ; 22:4, s. 553-567
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Tidskriftsartikel (refereegranskat)abstract
- Inhibiting pathologic angiogenesis can halt disease progression, but such inhibition may offer only a temporary benefit, followed by tissue revascularization after treatment stoppage. This revascularization, however, occurs by largely unknown phenotypic changes in pathologic vessels. To investigate the dynamics of vessel reconfiguration during revascularization, we developed a model of reversible murine corneal angiogenesis permitting longitudinal examination of the same vasculature. Following 30 days of angiogenesis inhibition, two types of vascular structure were evident: partially regressed persistent vessels that were degenerate and barely functional, and fully regressed, non-functional empty basement membrane sleeves (ebms). While persistent vessels maintained a limited flow and retained collagen IV+ basement membrane, CD31+ endothelial cells (EC), and alpha-SMA+ pericytes, ebms were acellular and expressed only collagen IV. Upon terminating angiogenesis inhibition, transmission electron microscopy and live imaging revealed that revascularization ensued by a rapid reversal of EC degeneracy in persistent vessels, facilitating their phenotypic normalization, vasodilation, increased flow, and subsequent new angiogenic sprouting. Conversely, ebms were irreversibly sealed from the circulation by excess collagen IV deposition that inhibited EC migration and prevented their reuse. Fully and partially regressed vessels therefore have opposing roles during revascularization, where fully regressed vessels inhibit new sprouting while partially regressed persistent vessels rapidly reactivate and serve as the source of continued pathologic angiogenesis.
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| 31. |
- Mukwaya, Anthony, et al.
(författare)
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Time-dependent LXR/RXR pathway modulation characterizes capillary remodeling in inflammatory corneal neovascularization
- 2018
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Ingår i: Angiogenesis. - : Springer Netherlands. - 0969-6970 .- 1573-7209. ; 21:2, s. 395-413
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation in the normally immune-privileged cornea can initiate a pathologic angiogenic response causing vision-threatening corneal neovascularization. Inflammatory pathways, however, are numerous, complex and are activated in a time-dependent manner. Effective resolution of inflammation and associated angiogenesis in the cornea requires knowledge of these pathways and their time dependence, which has, to date, remained largely unexplored. Here, using a model of endogenous resolution of inflammation-induced corneal angiogenesis, we investigate the time dependence of inflammatory genes in effecting capillary regression and the return of corneal transparency. Endogenous capillary regression was characterized by a progressive thinning and remodeling of angiogenic capillaries and inflammatory cell retreat in vivo in the rat cornea. By whole-genome longitudinal microarray analysis, early suppression of VEGF ligand-receptor signaling and inflammatory pathways preceded an unexpected later-phase preferential activation of LXR/RXR, PPAR alpha/RXR alpha and STAT3 canonical pathways, with a concurrent attenuation of LPS/IL-1 inhibition of RXR function and Wnt/beta-catenin signaling pathways. Potent downstream inflammatory cytokines such as Cxcl5, IL-1 beta, IL-6 and Ccl2 were concomitantly downregulated during the remodeling phase. Upstream regulators of the inflammatory pathways included Socs3, Sparc and ApoE. A complex and coordinated time-dependent interplay between pro- and anti-inflammatory signaling pathways highlights a potential anti-inflammatory role of LXR/RXR, PPAR alpha/RXR alpha and STAT3 signaling pathways in resolving inflammatory corneal angiogenesis.
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| 32. |
- Wiklund, Anna, et al.
(författare)
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ACUTE EXUDATIVE POLYMORPHOUS VITELLIFORM MACULOPATHY IN A YOUNG WOMAN: PRESYMPTOMATIC FINDINGS AND 21-MONTH FOLLOW-UP
- 2013
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Ingår i: RETINAL Cases & Brief Reports. - 1935-1089. ; 7:2, s. 123-127
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe ocular findings before and after the diagnosis of acute exudative polymorphous vitelliform maculopathy, in an otherwise healthy 28-year-old woman.Methods: Case report with 21-months of follow-up. Fundus photography, optical coherence tomography, fluorescein angiography, indocyanine green angiography, and autofluorescence were used for imaging the retina. To examine retinal function, full-field electroretinogram, multifocal electroretinogram, electrooculography, and dark adaptometry were performed. Genetic analysis for mutations associated with Best disease was done.Results: In the asymptomatic patient before diagnosis, white-yellow, drusen-like, subretinal depositions were found in both eyes. A few months later, the patient developed bilateral visual disturbances. Retinal examination at the acute phase revealed a characteristic pattern of multifocal white-yellow subretinal lesions in both posterior poles, imaged by ophthalmoscopy, fluorescein angiography, indocyanine green angiography, and optical coherence tomography. Additionally, electrooculography and dark adaptometry were abnormal. Full-field electroretinogram was normal, but multifocal electroretinogram revealed central depression of peak amplitudes. During the 21-month follow-up without any treatment, visual acuity recovered, electrooculography and dark adaptometry normalized, and the patient experienced one episode of relapse. Genetic studies excluded mutations in the bestrophin gene (BEST1).Conclusion: Acute exudative polymorphous vitelliform maculopathy is still a condition of unknown origin, primarily affecting the pigment epithelium. Earlier reports have discussed whether the condition is inherited or acquired. In this report, the presymptomatic retinal findings in acute exudative polymorphous vitelliform maculopathy are described for the first time, indicating that a condition may be associated with primarily affected retinal pigment epithelium.
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| 33. |
- Xeroudaki, Maria, et al.
(författare)
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A double-crosslinked nanocellulose-reinforced dexamethasone-loaded collagen hydrogel for corneal application and sustained anti-inflammatory activity
- 2023
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Ingår i: Acta Biomaterialia. - : Elsevier. - 1742-7061 .- 1878-7568. ; 172, s. 234-248
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Tidskriftsartikel (refereegranskat)abstract
- In cases of blinding disease or trauma, hydrogels have been proposed as scaffolds for corneal regenera-tion and vehicles for ocular drug delivery. Restoration of corneal transparency, augmenting a thin cornea and postoperative drug delivery are particularly challenging in resource-limited regions where drug avail-ability and patient compliance may be suboptimal. Here, we report a bioengineered hydrogel based on porcine skin collagen as an alternative to human donor corneal tissue for applications where long-term stability of the hydrogel is required. The hydrogel is reinforced with cellulose nanofibers extracted from the Ciona intestinalis sea invertebrate followed by double chemical and photochemical crosslinking. The hydrogel is additionally loaded with dexamethasone to provide sustained anti-inflammatory activity. The reinforced double-crosslinked hydrogel after drug loading maintained high optical transparency with sig-nificantly improved mechanical characteristics compared to non-reinforced hydrogels, while supporting a gradual sustained drug release for 60 days in vitro . Dexamethasone, after exposure to crosslinking and sterilization procedures used in hydrogel production, inhibited tube formation and cell migration of TNF alpha-stimulated vascular endothelial cells. The drug-loaded hydrogels suppressed key pro-inflammatory cytokines CCL2 and CXCL5 in TNF alpha-stimulated human corneal epithelial cells. Eight weeks after intra-stromal implantation in the cornea of 12 New-Zealand white rabbits subjected to an inflammatory suture stimulus, the dexamethasone-releasing hydrogels suppressed TNF alpha, MMP-9, and leukocyte and fibrob-last cell invasion, resulting in reduced corneal haze, sustained corneal thickness and stromal morphology, and reduced overall vessel invasion. This collagen-nanocellulose double-crosslinked hydrogel can be im-planted to treat corneal stromal disease while suppressing inflammation and maintaining transparency after corneal transplantation. Statement of significance To treat blinding diseases, hydrogel scaffolds have been proposed to facilitate corneal restoration and ocular drug delivery. Here, we improve on a clinically tested collagen-based scaffold to improve me-chanical robustness and enzymatic resistance by incorporating sustainably sourced nanocellulose and dual chemical-photochemical crosslinking to reinforce the scaffold, while simultaneously achieving sus-tained release of an incorporated anti-inflammatory drug, dexamethasone. Evaluated in the context of a corneal disease model with inflammation, the drug-releasing nanocellulose-reinforced collagen scaffold maintained the cornea's transparency and resisted degradation while suppressing inflammation postop-
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| 34. |
- Xeroudaki, Maria, 1989-
(författare)
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Advanced surgeries, medicines and materials for corneal regeneration
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Corneal transplantation is often the only treatment option in cases of corneal blindness, with the main challenges being the scarcity of human donors, risk for graft failure and suboptimal visual outcome due to suture-related issues. Alternative therapies are sought that either address the above transplantation issues directly or stimulate the cornea’s repair mechanism and regenerative properties to restore transparency without the need for transplantation. The first aim of this thesis was to develop a cell-free substitute for the human corneal stroma made of porcine collagen, a purified byproduct from the food industry that is already approved by FDA as a raw material, used for example in cosmetic surgery or as a medical device in glaucoma surgery. Abundance, cost-effectiveness, low rejection risk due to acellularity, high purity and worldwide availability are among the main advantages of purified porcine collagen compared to human donors and other corneal stromal substitutes. The second aim was to address the risk of graft rejection in cases of neovascularized and inflamed corneas by loading the bioengineered porcine collagen constructs with drugs that can ideally promote corneal regeneration, secure the survival of the graft in cases of high-risk keratoplasties and minimize the need for prolonged topical immunosuppressive therapy following operation, which has drawbacks of low bioavailability and need for good patient compliance. The third aim was to develop alternative techniques of lamellar transplantation, all assisted by femtosecond laser, that are less suture-dependent and enable the intrastromal implantation of biomaterials. Finally, the fourth aim of this thesis was to evaluate the role of Regenerating Agent (RGTA) eye drops in corneal wound healing following therapeutic laser ablation of the cornea in a randomised, blinded, placebo-controlled preclinical study. Regenerating Agent is a biomimetic of extracellular matrix with well-established favourable outcomes in the treatment of skin wounds and preliminary positive results in the treatment of corneal wounds. Different manufacturing protocols were used to enhance the mechanical properties of bioengineered porcine collagen (BPC) and to address different requirements. The combination of both chemical and photochemical crosslinking with riboflavin and ultraviolet A light (to form BPCDX) and reinforcement with cellulose nanofibers extracted from the Ciona intestinalis sea invertebrate (BPCDX-CNF) resulted in stronger biomaterials compared to earlier BPC versions. The biomaterials could be manufactured in different sizes and in core-and-skirt forms with the peripheral skirt degrading faster due to mechanical compression without the addition of any cross-linkers during manufacturing. BPC could be successfully loaded with nerve growth factor (NGF) and BPCDX-CNF with dexamethasone without sacrificing transparency and both drugs could be released from BPC-based materials in vitro up to at least 2 months. The biological activity of dexamethasone released from the drug-loaded BPCDX-CNF could be confirmed by the decreased expression of inflammatory cytokines in human corneal epithelial cells grown on dexamethasone-loaded BPCDX-CNF. A compatible packaging and sterilization process was developed for BPCDX, tested internally and externally by Good Laboratory Practice-certified laboratories, that can enable worldwide distribution and storage at room temperature or in a refrigerator up to two years without the need of extra quality controls before transplantation. BPC-based materials could be safely implanted in rabbit, minipig and human corneas with advanced keratoconus using femtosecond-laser assisted intrastromal keratoplasty procedures. A femtosecond laser was used to create intrastromal pockets of different dimensions based on the size of the biomaterials. Through an access cut or by lifting a flap, both created by femtosecond laser, biomaterials could be implanted intrastromally with or without native tissue removal. Additional sutures were used in a surgical inflammatory model to test the biological activity of dexamethasone released by BPCDX-CNF. These minimally invasive surgical procedures required shorter period of immunosuppression following operation and maintained the anatomy of the surrounding host tissue. Apart from the skirt part of the composite BPC that was mechanically compressed and was designed to degrade faster, the crosslinked BPC remained stable in animal models, while no degradation was observed in the BPCDX 2 years after implantation in humans. The biomaterials were biocompatible and native cells were found in the biomaterial-host interface or in the periphery of the biomaterial. The inflammatory response following operation depended on individual response to injury and did not appear to be stimulated by BPC implantation. Neovascularization and haze formation were mainly restricted around the sutures used to secure either the access cut or flap overlying the biomaterials as well as intentionally placed close to the limbus to trigger inflammation in the dexamethasone study. In the human studies, no sutures were used and corneal transparency was maintained at the highest level in all subjects after 2 years without any signs of rejection, inflammation, vascularization or scarring. Topographic indices including mean anterior corneal curvature and maximal corneal apical curvature were significantly reduced in both clinical cohorts resulting in improved best corrected visual acuity. Importantly, following operation all human subjects could tolerate contact lenses and no subject was considered legally blind. The release of dexamethasone from the drug-loaded BPCDX-CNF could be also confirmed in vivo by sustained intraocular pressure increase, tendency to reduce neovascularization and haze formation and sustained suppression of inflammatory cytokines in the aqueous humor of eyes implanted with dexamethasone-loaded BPCDX-CNF compared to non-loaded BPCDX-CNF. Finally, RGTA eye drops following excimer laser ablation of the anterior healthy rabbit cornea did not affect the already quick and uneventful epithelial closure. Although there was significantly less haze in the RGTA group compared to placebo as measured by in vivo confocal microscopy, this decrease was not clinically relevant as all corneas in both groups were clinically transparent following laser. The microscopic haze formation and staining problems did not allow quantification of nerve regeneration, but subbasal nerves were found to repopulate the central ablated regions in both RGTA and placebo groups. In conclusion, our results indicate that biomaterials made of bioengineered porcine collagen are a safe alternative to human donor tissue for corneal transplantation, offering the advantage of custom-made manufacturing to address different requirements with potential applications to different corneal stromal diseases. Femtosecond laser enables safe intrastromal implantation of biomaterials with less suture-related issues and immunosuppression following operation compared to traditional corneal transplantation methods. Regenerating Agent eye drops do not affect the already rapid wound healing following laser ablation of the healthy cornea.
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| 35. |
- Xeroudaki, Maria, et al.
(författare)
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RGTA in corneal wound healing after transepithelial laser ablation in a rabbit model: a randomized, blinded, placebo-controlled study
- 2016
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Ingår i: Acta Ophthalmologica. - : WILEY-BLACKWELL. - 1755-375X .- 1755-3768. ; 94:7, s. 685-691
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Tidskriftsartikel (refereegranskat)abstract
- PurposeTo evaluate the efficacy of the agent RGTA for epithelial, stromal and nerve regeneration after laser-induced corneal wounding in rabbits. MethodsAfter excimer laser wounding of the anterior cornea in 25 New Zealand white rabbits, topical RGTA or placebo was applied in a randomized, masked manner. Fluorescein epithelial staining was performed on the first 5 postoperative days. In vivo confocal microscopy of corneal subbasal nerves and stroma was performed preoperatively and on week 2, 4, 8 and 16. At 16weeks, corneas were stained for beta-III tubulin expression. ResultsPostoperatively, all epithelia had closed by at least 90% after the third postoperative day. No significant difference in epithelial wound size was found between RGTA and placebo-treated groups, and RGTA did not hinder fluorescein binding. After epithelial wound closure, corneas remained transparent to 16weeks. By confocal microscopy, subclinical stromal haze was significantly deeper in placebo-treated eyes (mean depth 60m) relative to RGTA group (52m), p=0.02. Regenerating beta-III tubulin-positive subbasal nerves were observed in all corneas, but partial masking by haze rendered quantitative analysis unreliable. ConclusionsRGTA restored stromal microarchitecture and reduced subclinical haze relative to placebo. The mild epithelial wound quickly healed regardless of treatment suggesting an optimal natural healing process in freshly wounded healthy corneas, and indicating that RGTA may be more suitable for healing of chronic or more aggressive wounds. Limitations of the rabbit model for nerve quantification in the presence of haze should also be recognized.
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