| 1. |
- Adil, Mohammed Yasin, et al.
(författare)
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Meibomian Gland Morphology Is a Sensitive Early Indicator of Meibomian Gland Dysfunction
- 2019
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Ingår i: American Journal of Ophthalmology. - : ELSEVIER SCIENCE INC. - 0002-9394 .- 1879-1891. ; 200, s. 16-25
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate the relationship between meibomian gland (MG) morphology and clinical dry eye tests in patients with meibomian gland dysfunction (MGD). DESIGN: Cross-sectional study. SUBJECTS: Total 538 MGD patients and 21 healthy controls. METHODS: MG loss on meibography images of upper (UL) and lower lids (LL) was graded on a scale of 0 (lowest degree of MG loss) to 3. MG length, thickness, and interglandular space in the UL were measured. Clinical tests included meibum expression and quality, tear film break-up time, ocular staining, osmolarity, Schirmer I, blink interval timing, and Ocular Surface Disease Index (OSDI) questionnaire. RESULTS: Mean UL and LL meibogrades were significantly higher in MGD patients compared to controls (P amp;lt; .001 for UL and LL). The sensitivity and specificity of the meibograde as a diagnostic parameter for MGD was 96.7% and 85%, respectively. Schirmer I was significantly increased in MGD patients with meibograde 1 compared to patients with meibograde 0, 2, and 3 in the UL (P amp;lt; .05 ). MG thickness increased with higher meibograde (P amp;lt; .001). MG morphology correlated significantly but weakly with several clinical parameters (P amp;lt; .05). OSDI did not correlate with any MG morphologic parameter. CONCLUSIONS: Grading of MG loss using meibograde effectively diagnoses MGD. Compensatory mechanisms such as increased aqueous tear production and dilation of MGs make early detection of MGD difficult by standard clinical measures of dry eye, whereas morphologic analysis of MGs reveals an early stage of MGD, and therefore represents a complementary clinical parameter with diagnostic potential. (C) 2018 Elsevier Inc. All rights reserved.
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| 2. |
- Al-Hawasi, Abbas, et al.
(författare)
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Longitudinal Optical Coherence Tomography Measurement of Retinal Ganglion Cell and Nerve Fiber Layer to Assess Benign Course in Multiple Sclerosis
- 2023
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- A benign form of multiple sclerosis (BMS) is not easily diagnosed, but changes of the retinal ganglion cell layer-inner plexiform layer (GCL-IPL) and retinal nerve fiber layer (RNFL) may be sensitive to the disease. The aim of this study was to use optical coherence tomography (OCT) to investigate longitudinal changes of GCL-IPL and RNFL in BMS. Eighteen patients with BMS and 22 healthy control (HC) subjects were included, with a mean follow-up period of 32.1 months in BMS and 34.3 months in HC. Mean disease duration in BMS was 23.3 years, with 14 patients left untreated. Unilateral optic neuritis (ON) was found in eight patients. Non-ON eyes showed thinner GCL-IPL layer in the BMS group relative to HC (p < 0.001). The thinning rate of GCL-IPL in non-ON BMS, however, was -0.19 +/- 0.15 mu m/year vs. 0 +/- 0.11 mu m/year for HC (p = 0.573, age-adjusted). Thinning rate of RNFL in non-ON BMS was -0.2 +/- 0.27 mu m/year vs. -0.05 +/- 0.3 mu m/year for HC (p = 0.454, age adjusted). Conclusions: Thinning rate of the GCL-IPL and RNFL in BMS is similar to the healthy population but differs from the thinning rate in relapsing-remitting MS, presenting a non-invasive OCT-based criterion for assessing a benign course in multiple sclerosis.
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| 3. |
- Al-Hawasi, Abbas, 1976-
(författare)
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Retinal ganglion cell examination with Optical Coherence Tomography reflects physiological and pathological changes in the eye and the brain.
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The retinal ganglion cell is situated in the inner retina and its axons, composing the retinal nerve fiber layer (RNFL), leave the eye to form the optic nerve. These cells develop embryologically from the forebrain and later during development re-establish connections with different parts of the brain serving different purposes. This unique position and connections make it possible to be investigated with different methods. Optical Coherence Tomography (OCT) is an accessible and easily operated clinical device that can provide a detailed image of this layer at a few micrometers level of precision in measurements. In this thesis we aimed to see whether examining these cells with OCT could reflect physiological and pathological changes in the eye and brain.In cases of optic neuritis (Paper I), the OCT examination showed early thickening of the peripapillary (pRNFL) followed by thinning which takes 6-9 months to reduce to below normal thickness without the ability to distinguish between the real from pseudo thinning. The ganglion cell -inner plexiform layer (GCL-IPL) layer, however, showed a thickness reduction within a few weeks to 3 months without pseudo thinning. In cases of Idiopathic Intracranial Hypertension (IIH) (Paper II), the GCL-IPL remained unchanged and there was no difference in pRNFL thickness compared to healthy controls, whereas the optic disc parameters of rim thickness, rim area, cup volume and cup/disc ratio differed significantly (P<0.05).In cases of benign multiple sclerosis (Paper IV), the OCT could detect that eyes which are not affected by optic neuritis had an annual thinning rate of the RNFL and GCL-IPL similar to a healthy population (P>0.05) which may indicate the benign course of the disease. In cases of physiological factors affecting the GCL in healthy population (Paper III) the OCT examination showed that there was a significant thinning rate of the layer with age (P<0.05), but the thinning was not significant when sex and axial length of the eye were taken into consideration. Males had a thicker GCL volume than females and with age a significant reduction in GCL volume was noted in females but not in males. A Longer axial length of the eye found to be associated with thinner GCL volume. In conclusion retinal ganglion cell changes detected with OCT can reflect physiological and pathological changes in the eye and brain.
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| 4. |
- Al-Hawasi, Abbas, 1976-, et al.
(författare)
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Retinal ganglion cell layer thickness and volume measured by OCT changes with age, sex, and axial length in a healthy population
- 2022
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Ingår i: BMC Ophthalmology. - : BMC. - 1471-2415. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background The ganglion cell layer (GCL) measurements with Optical Coherence Tomography (OCT) are important for both ophthalmologists and neurologists because of their association with many ophthalmic and neurological diseases. Different factors can affect these measurements, such as brain pathologies, ocular axial length (AL) as well as age and sex. Studies conducted to measure the GCL have overlooked many of these factors. The purpose of this study is to examine the effect of age, sex, and AL on normal retinal GCL thickness and volume in a healthy population without any neurological diseases. Methods A prospective cross-sectional study was designed to measure GCL thickness and total volume with OCT with automated segmentation and manual correction where needed. Visual acuity, AL, and autorefraction were also measured. A mixed linear model was used to determine the association of the effect of the various parameters on the GCL thickness and volume. Results One hundred and sixteen eyes of 60 subjects (12-76 years of age, 55% female) were examined of which 77% had 0 +/- 2 D of spherical equivalent, and mean axial length was 23.86 mm. About 25% of the OCT-automated GCL measurements required manual correction. GCL thickness did not differ in similar anatomic regions in right and left eyes (P > 0.05). GCL volume was greater in males relative to females after adjustment for age and axial length (1.13 +/- 0.07 mm(3) for males vs 1.09 +/- 0.09 mm(3) for females; P = 0.031). GCL thickness differed between males and females in the inner retinal ring (P = 0.025) but not in the outer ring (P = 0.66). GCL volume declined with age (P = 0.031) but not after adjustment for sex and axial length (P = 0.138). GCL volume declined with longer axial length after adjustment for age and sex (P = 0.048). Conclusion Age, sex and axial length should be taken into consideration when measuring the GCL thickness and volume with OCT. Automated OCT segmentation should be reviewed for manual adjustments.
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| 5. |
- 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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| 6. |
- Ali, Zaheer, 1984-
(författare)
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Investigating mechanisms of angiogenesis in health and disease using zebrafish models
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Angiogenesis, the growth of blood vessels from an existing vasculature, can occur by sprouting from preexisting vessels or by vessel splitting (intussusception). Pathological angiogenesis drives choroidal neovascularization (CNV) in age related macular degeneration (AMD) which is commonly restricted under the retinal pigment epithelium (RPE), called occult CNV, but may also involve vessels penetrating through the RPE into the sub-retinal space. Pathological vessels are poorly developed, insufficiently perfused and highly leaky, phenotypes that are considered to drive disease progression and lead to poor prognosis. Currently, a number of anti-angiogenic drugs exists, the majority of which target vascular endothelial factor (VEGF), but although they often are highly beneficial for treating eye diseases in the short-term, they are generally of limited efficacy in other diseases such as cancer, and also have poorer efficacy when used for treatment of eye diseases in the long-term. A better understanding of the mechanisms underlying pathological angiogenesis can generate new targets for treatment leading to development of better drugs for cancer and retinopathies, but perhaps also other angiogenesis-dependent diseases, in the future. In this thesis mechanisms involved in developmental angiogenesis or pathological angiogenesis in the choroid, cornea or melanoma was identified. These findings highlight the need to further elaborate our knowledge related to angiogenesis in different tissues/conditions for a more targeted, and potentially effective treatment of diseases in the future.In paper I, we for the first time identified the choriocapillaries (CCs) in adult zebrafish and found that occult CNV could be induced by exposing the fish to severe hypoxia. Interestingly, we found that occult CNV relied on intussusception, involving not only de novo generation of intussusceptive pillars but also a previously poorly understood mechanism called pillar splitting. This involved HIF-VEGF-VEGFR2 signaling and evidence that this also occurred in both rats and humans suffering from AMD suggested that the mechanism was conserved and clinically relevant.In contrast, we found in paper II that the development of CCs in the zebrafish relies on sprouting angiogenesis, involve continuous remodeling, and delayed maturation of the vasculature in 2D. The initial development was found to occur by a unique process of tissuewide synchronized vasculogenesis. As expected, VEGFA via VEGFR2 was also critical for the development of these vessels in the zebrafish embryo, but surprisingly this was independent on hypoxia-inducible factor (HIF)-1.Inflammatory nuclear factor-kB (NF-kB) signaling is involved in the progression of angiogenesis, but this signaling pathway has mainly been studied in the inflammatory cells and the role of NF-kB in the endothelial cells during angiogenesis is poorly understood. In paper III, we found that blocking NF-kB signaling using a specific IKK2 blocker IMD0354, specifically blocks pathological as well as developmental angiogenesis by targeting endothelial cell NF-kB signaling in the endothelial cells. Using a rat model for suture-induced corneal neovascularization, IMD0354 treatment lead to reduced production of inflammatory C-C motif chemokine ligand 2 (CCL2), C-X-C motif chemokine ligand 5 (CXCL5) and VEGF, and thereby reduced pathological corneal angiogenesis in this model.Using the zebrafish tumor xenograft model in paper IV, we found an association between Microphthalmia associated transcription factor (MITF) and pigment epithelium derived factor (PEDF), which was involved in pathological tumor angiogenesis and metastasis. Similarly, in paper V we used zebrafish transplantation models to study and investigate the use of biocompatible polymers for the delivery of pro-angiogenic FGF-2 as a potential treatment strategy for ischemic diseases such as myocardial infarction (MI). Conclusively, this thesis provides new insights into diverse fields of angiogenic assays using zebrafish, and reveals new mechanisms of angiogenesis in health and disease. This work will hopefully provide a foundation for further studies into occult CNV related to AMD, a process that has not been possible to study previously in pre-clinical models. In addition, zebrafish xenograft or other transplantation models used in this work will likely be important to study cancer biology and to develop more attractive pharmaceutical preparations based on biocompatible hydrogels formulated as microspheres in the future.
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| 7. |
- Ali, Zaheer, et al.
(författare)
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Photoreceptor Degeneration Accompanies Vascular Changes in a Zebrafish Model of Diabetic Retinopathy
- 2020
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Ingår i: Investigative Ophthalmology and Visual Science. - : ASSOC RESEARCH VISION OPHTHALMOLOGY INC. - 0146-0404 .- 1552-5783. ; 61:2
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. Diabetic retinopathy (DR) is a leading cause of vision impairment and blindness worldwide in the working-age population, and the incidence is rising. Until now it has been difficult to define initiating events and disease progression at the molecular level, as available diabetic rodent models do not present the full spectrum of neural and vascular pathologies. Zebrafish harboring a homozygous mutation in the pancreatic transcription factor pdx1 were previously shown to display a diabetic phenotype from larval stages through adulthood. In this study, pdx1 mutants were examined for retinal vascular and neuronal pathology to demonstrate suitability of these fish for modeling DR. METHODS. Vessel morphology was examined in pdx1 mutant and control fish expressing the fli1a:EGFP transgene. We further characterized vascular and retinal phenotypes in mutants and controls using immunohistochemistry, histology, and electron microscopy. Retinal function was assessed using electroretinography. RESULTS. Pdx1 mutants exhibit clear vascular phenotypes at 2 months of age, and disease progression, including arterial vasculopenia, capillary tortuosity, and hypersprouting, could be detected at stages extending over more than 1 year. Neural-retinal pathologies are consistent with photoreceptor dysfunction and loss, but do not progress to blindness. CONCLUSIONS. This study highlights pdx1 mutant zebrafish as a valuable complement to rodent and other mammalian models of DR, in particular for research into the mechanistic interplay of diabetes with vascular and neuroretinal disease. They are furthermore suited for molecular studies to identify new targets for treatment of early as well as late DR.
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| 8. |
- Andreasson, M., et al.
(författare)
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Parkinson's disease with restless legs syndrome-an in vivo corneal confocal microscopy study
- 2021
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Ingår i: npj Parkinson's Disease. - : Springer Science and Business Media LLC. - 2373-8057. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Small fiber neuropathy (SFN) has been suggested as a trigger of restless legs syndrome (RLS). An increased prevalence of peripheral neuropathy has been demonstrated in Parkinson's disease (PD). We aimed to investigate, in a cross-sectional manner, whether SFN is overrepresented in PD patients with concurrent RLS relative to PD patients without RLS, using in vivo corneal confocal microscopy (IVCCM) and quantitative sensory testing (QST) as part of small fiber assessment. Study participants comprised of age- and sex-matched PD patients with (n = 21) and without RLS (n = 21), and controls (n = 13). Diagnosis of RLS was consolidated with the sensory suggested immobilization test. Assessments included nerve conduction studies (NCS), Utah Early Neuropathy Scale (UENS), QST, and IVCCM, with automated determination of corneal nerve fiber length (CNFL) and branch density (CNBD) from wide-area mosaics of the subbasal nerve plexus. Plasma neurofilament light (p-NfL) was determined as a measure of axonal degeneration. No significant differences were found between groups when comparing CNFL (p = 0.81), CNBD (p = 0.92), NCS (p = 0.82), and QST (minimum p = 0.54). UENS scores, however, differed significantly (p = 0.001), with post-hoc pairwise testing revealing higher scores in both PD groups relative to controls (p = 0.018 and p = 0.001). Analysis of all PD patients (n = 42) revealed a correlation between the duration of l-dopa therapy and CNBD (rho = -0.36, p = 0.022), and p-NfL correlated with UENS (rho = 0.35, p = 0.026) and NCS (rho = -0.51, p = 0.001). Small and large fiber neuropathy do not appear to be associated with RLS in PD. Whether peripheral small and/or large fiber pathology associates with central neurodegeneration in PD merits further longitudinal studies.
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| 9. |
- Badian, Reza A., et al.
(författare)
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Comparison of novel wide-field in vivo corneal confocal microscopy with skin biopsy for assessing peripheral neuropathy in type 2 diabetes
- 2023
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 72:7, s. 908-917
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Tidskriftsartikel (refereegranskat)abstract
- Diabetic peripheral neuropathy (DPN) is a serious complication of diabetes, where skin biopsy assessing intraepi-dermal nerve fiber density (IENFD) plays an important diagnostic role. In vivo confocal microscopy (IVCM) of the corneal subbasal nerve plexus has been proposed as a noninvasive diagnostic modality for DPN. Direct compari-sons of skin biopsy and IVCM in controlled cohorts are lacking, as IVCM relies on subjective selection of images depicting only 0.2% of the nerve plexus. We compared these diagnostic modalities in a fixed-age cohort of 41 participants with type 2 diabetes and 36 healthy participants using machine algorithms to create wide-field image mosaics and quantify nerves in an area 37 times the size of prior studies to avoid human bias. In the same partici-pants, and at the same time point, no correlation between IENFD and corneal nerve density was found. Corneal nerve density did not correlate with clinical measures of DPN, including neuropathy symptom and disability scores, nerve conduction studies, or quantitative sensory tests. Our findings indicate that corneal and intraepidermal nerves likely mirror different aspects of nerve degeneration, where only intraepidermal nerves appear to reflect the clinical status of DPN, suggesting that scrutiny is warranted concerning methodologies of studies using corneal nerves to assess DPN.
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| 10. |
- Badian, Reza A., et al.
(författare)
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Region of interest and directional analysis of subbasal nerves in wide-area corneal nerve plexus mosaics in type 2 diabetes mellitus
- 2020
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- In vivo confocal microscopy (IVCM) imaging of the corneal subbasal nerve plexus (SBNP) is a clinical imaging modality gaining popularity for the diagnosis and follow-up of corneal neuropathy in various conditions such as diabetes mellitus. There remain, however, major limitations to the method, hindering its widespread clinical use. Finding the same exact area of the central cornea to standardize image acquisition is difficult without a reference point. Alternatively, creating wide-area mosaics of the SBNP is resource-intensive and has not yet been developed for routine clinical use. Here, we investigated whether IVCM analysis of the corneal SBNP in a predetermined, anatomically standardized region of interest (ROI) could be applied as an equivalent substitution for wide-area SBNP mosaic generation and analysis. Furthermore, we investigated nerve patterns outside the central corneal region for a possible relationship to type 2 diabetes mellitus status using a publicly available dataset. We found that corneal nerve fibre length density (CNFL) based on the ROI underestimated the mosaic-based CNFL by an average of 34% in 90% of cases (150 eyes), and did not exhibit a significant reduction with diabetes, as seen in the full SBNP. Outside the central cornea, nerve orientation differed depending on the anatomic region (left, central or right superior plexus, P<0.001). Moreover, in long-term type 2 diabetes mellitus (>= 10 years, 28 subjects), nerve density in the left superior sector of the SBNP was decreased (P<0.001) while that in the central superior SBNP increased (P=0.01) relative to 35 age-matched healthy subjects with normal glucose tolerance. These results indicate that subbasal nerve degeneration in type 2 diabetes mellitus can vary according to anatomic location, and regions with potential diagnostic value outside the central SBNP may warrant further investigation.
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| 11. |
- Badian, Reza A., et al.
(författare)
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The pattern of the inferocentral whorl region of the corneal subbasal nerve plexus is altered with age
- 2021
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Ingår i: The Ocular Surface. - : Elsevier. - 1542-0124 .- 1937-5913. ; 22, s. 204-212
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe the pattern of the nerves in the inferocentral whorl region of the human corneal subbasal nerve plexus (SBNP) in health and diseases known to affect the subbasal nerves. Methods: Laser-scanning in vivo confocal microscopy (IVCM) was used to image the SBNP bilaterally in 91 healthy subjects, 39 subjects with type 2 diabetes mellitus (T2DM), and 43 subjects with Parkinsons disease (PD). Whorl regions were classified according to nerve orientation relative to age and health/disease status. Results: Of 346 examined eyes, 300 (86.7%) had an identifiable whorl pattern. In healthy subjects, a clockwise nerve orientation of the whorl was most common (67.9%), followed by non-rotatory or seam morphology (21.4%), and counterclockwise (10.7%). The clockwise orientation was more prevalent in healthy subjects than in T2DM or PD (P < 0.001). Healthy individuals below 50 years of age had a predominantly clockwise orientation (93.8%) which was reduced to 51.9% in those over 50 years (P < 0.001). Age but not disease status explained whorl orientation in T2DM and PD groups. Moreover, whorl orientation is bilaterally clockwise in the young, but adopts other orientations and becomes asymmetric across eyes with age. Finally, we report reflective dot-like features confined to the whorl region of the subbasal plexus, sometimes appearing in close association with subbasal nerves and present in 84-93% of examined eyes regardless of disease status, eye or sex. Conclusion: Subbasal nerves in the inferocentral whorl region are predominantly clockwise in young, healthy corneas. With aging and conditions of T2DM and PD, counterclockwise and non-rotatory configurations increase in prevalence, and bilateral symmetry is lost. Mechanisms regulating these changes warrant further investigation.
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| 12. |
- Badian, Reza A., et al.
(författare)
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Wide-field mosaics of the corneal subbasal nerve plexus in Parkinsons disease using in vivo confocal microscopy
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- In vivo confocal microscopy (IVCM) is a non-invasive imaging technique facilitating real-time acquisition of images from the live cornea and its layers with high resolution (1-2 mu m) and high magnification (600 to 800-fold). IVCM is extensively used to examine the cornea at a cellular level, including the subbasal nerve plexus (SBNP). IVCM of the cornea has thus gained intense interest for probing ophthalmic and systemic diseases affecting peripheral nerves. One of the main drawbacks, however, is the small field of view of IVCM, preventing an overview of SBNP architecture and necessitating subjective image sampling of small areas of the SBNP for analysis. Here, we provide a high-quality dataset of the corneal SBNP reconstructed by automated mosaicking, with an average mosaic image size corresponding to 48 individual IVCM fields of view. The mosaic dataset represents a group of 42 individuals with Parkinsons disease (PD) with and without concurrent restless leg syndrome. Additionally, mosaics from a control group (n = 13) without PD are also provided, along with clinical data for all included participants.
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| 13. |
- Bakken, Ingvild M., et al.
(författare)
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The use of in vivo confocal microscopy in fungal keratitis - Progress and challenges
- 2022
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Ingår i: Ocular Surface. - : Elsevier. - 1542-0124. ; 24, s. 103-118
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Tidskriftsartikel (refereegranskat)abstract
- Fungal keratitis (FK) is a serious and sight-threatening corneal infection with global reach. The need for prompt diagnosis is paramount, as a delay in initiation of treatment could lead to irreversible vision loss. Current "gold standard" diagnostic methods, namely corneal smear and culture, have limitations due to diagnostic insensitivity and their time-consuming nature. PCR is a newer, complementary method used in the diagnosis of fungal keratitis, whose results are also sample-dependent. In vivo confocal microscopy (IVCM) is a promising complementary diagnostic method of increasing importance as it allows non-invasive real-time direct visualization of potential fungal pathogens and manifesting infection directly in the patients cornea. In numerous articles and case reports, FK diagnosis by IVCM has been evaluated, and different features, approaches, sensitivity/specificity, and limitations have been noted. Here, we provide an up-to-date, comprehensive review of the current literature and present the authors combined recommendations for fungal identification in IVCM images, while also looking to the future of FK assessment by IVCM using artificial intelligence methods.
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| 14. |
- Behaegel, Josephine, et al.
(författare)
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Outcomes of Human Leukocyte Antigen-Matched Allogeneic Cultivated Limbal Epithelial Transplantation in Aniridia-Associated Keratopathy-A Single-Center Retrospective Analysis
- 2022
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Ingår i: Cornea. - : LIPPINCOTT WILLIAMS & WILKINS. - 0277-3740 .- 1536-4798. ; 41:1, s. 69-77
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To assess the efficacy and safety of human leukocyte antigen-matched allogeneic cultivated limbal epithelial stem cell grafts in the treatment of aniridia-associated keratopathy (AAK). Methods: Six eyes of 6 patients with severe AAK received an allogeneic stem cell graft between January 2010 and March 2017. Anatomical and functional results were assessed at 6 months, 1 year, 2 years, and the final follow-up visit available. Safety analysis was performed by considering all perioperative and postoperative adverse events and additional surgeries required during the follow-up period. Results: The mean follow-up was 53.6 months (range 24-104 months). In most patients (80%), there was an early improvement of the keratopathy postoperatively, which slowly regressed during longer follow-up. At the final follow-up, 4 of the eyes were graded as failure and 1 eye was graded as partial success. Grading the sixth eye was not possible because of an adverse event. None of the patients maintained a total anatomical success in the long-term. Only 1 patient maintained a modest improvement in best-corrected visual acuity from hand motion to counting fingers. Four serious adverse events were recorded in 2 patients. Conclusions: Severe AAK remains a challenging condition to manage. Transplantation of allogenic ex vivo cultivated limbal stem cells may provide a temporary improvement in ocular surface stability, but anatomical and functional results are poor in the long-term. The eyes are prone to adverse events, and any surgical treatment should take this into consideration.
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| 15. |
- 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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| 16. |
- 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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| 17. |
- 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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| 18. |
- 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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| 19. |
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| 20. |
- 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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| 21. |
- 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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| 22. |
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| 23. |
- Daruich, Alejandra, et al.
(författare)
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Congenital aniridia beyond black eyes: From phenotype and novel genetic mechanisms to innovative therapeutic approaches
- 2023
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Ingår i: Progress in retinal and eye research. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1350-9462 .- 1873-1635. ; 95
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Forskningsöversikt (refereegranskat)abstract
- Congenital PAX6-aniridia, initially characterized by the absence of the iris, has progressively been shown to be associated with other developmental ocular abnormalities and systemic features making congenital aniridia a complex syndromic disorder rather than a simple isolated disease of the iris. Moreover, foveal hypoplasia is now recognized as a more frequent feature than complete iris hypoplasia and a major visual prognosis determinant, reversing the classical clinical picture of this disease. Conversely, iris malformation is also a feature of various anterior segment dysgenesis disorders caused by PAX6-related developmental genes, adding a level of genetic complexity for accurate molecular diagnosis of aniridia. Therefore, the clinical recognition and differential genetic diagnosis of PAX6-related aniridia has been revealed to be much more challenging than initially thought, and still remains under-investigated. Here, we update specific clinical features of aniridia, with emphasis on their genotype correlations, as well as provide new knowledge regarding the PAX6 gene and its mutational spectrum, and highlight the beneficial utility of clinically implementing targeted Next-Generation Sequencing combined with Whole-Genome Sequencing to increase the genetic diagnostic yield of aniridia. We also present new molecular mechanisms underlying aniridia and aniridia-like phenotypes. Finally, we discuss the appropriate medical and surgical management of aniridic eyes, as well as innovative therapeutic options. Altogether, these combined clinical-genetic approaches will help to accelerate time to diagnosis, provide better determination of the disease prognosis and management, and confirm eligibility for future clinical trials or genetic-specific therapies.
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