| 61. |
|
|
| 62. |
|
|
| 63. |
- Germundsson, Johan, et al.
(författare)
-
Age-Related Thinning of Bowman's Layer in the Human Cornea In Vivo
- 2013
-
Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 54:9, s. 6143-6149
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose. To determine the thickness of Bowman's layer (BL) in vivo in a healthy population and to determine its variation with age.Methods. Eighty-two subjects aged 15 to 88 years with clear, healthy corneas were examined bilaterally with laser scanning in vivo confocal microscopy (IVCM). Bowman's layer thickness was determined from IVCM images of anterior and posterior BL boundaries. For a given eye, BL thickness was averaged across four central locations by two independent observers. In addition, central corneal thickness was measured by time-domain optical coherence tomography.Results. A significant negative correlation of BL thickness with age was found in right eyes (Pearson r = −0.579, P < 0.0001) and in left eyes (r = −0.558, P < 0.0001). Linear regression analysis yielded a decline in BL thickness of 0.06 μm per year. In 41 older subjects (mean age, 64.4 years), BL thickness was significantly thinner (mean ± SD, 8.6 ± 1.7 μm in right eyes) than that in 41 younger subjects (mean age, 31.6 years) (mean ± SD, 10.7 ± 1.6 μm in right eyes) (P < 0.001). No correlation of corneal thickness with age or of BL thickness with corneal thickness was observed. Strong intereye correlations in BL thickness (r = 0.771, P < 0.0001) and corneal thickness (r = 0.969, P < 0.001) were found.Conclusions. Bowman's layer thins with age in the normal cornea, losing one-third of its thickness between the ages of 20 and 80 years. In vivo measurement of BL thickness by IVCM could aid in clinical assessment and planned treatments of the anterior cornea.
|
|
| 64. |
- Germundsson, Johan, et al.
(författare)
-
An Accurate Method to Determine Bowmans Layer Thickness In Vivo in the Human Cornea
- 2012
-
Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 53:4, s. 2354-2359
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. To determine an accurate value for Bowmans layer (BL) thickness in vivo in humans. less thanbrgreater than less thanbrgreater thanMETHODS. Seventeen corneal transplant patients were examined preoperatively by laser-scanning in vivo confocal microscopy (IVCM), and corneal buttons were removed post-operatively and sectioned for light microscopy (LM). Nine corneas with uniformly thick BL by LM were used for thickness measurement. In the uniformly thick samples, probable overestimation of BL thickness in vivo by a first in vivo method (Method 1) led to the development of a revised in vivo method (Method 2). Method 2 was used to measure BL thickness in 20 healthy volunteers. less thanbrgreater than less thanbrgreater thanRESULTS. In nine patients, mean BL thickness prior to transplantation was 13.7 +/- 1.6 mu m by IVCM (Method 1) while BL thickness of the removed corneal button was 9.7 +/- 1.7 mu m by LM (P andlt; 0.001). The correlation of BL thickness between IVCM (Method 1) and LM was poor (P = 0.226). In 20 right eyes of 20 normal corneas, both in vivo methods were used to determine BL thickness. Mean BL thickness by Method 1 was 13.2 +/- 1.6 mu m and by Method 2 was 9.1 +/- 1.4 mu m (P andlt; 0.001). BL thickness measurements by both in vivo methods were highly correlated (P andlt; 0.001). less thanbrgreater than less thanbrgreater thanCONCLUSION. BL thickness by a revised in vivo method was close to LM values in this study and to values reported in fixed tissue in other studies. The authors believe this revised method provides the most accurate estimates of BL thickness in vivo to date.
|
|
| 65. |
- Germundsson, Johan, et al.
(författare)
-
Pathologically reduced subbasal nerve density in epithelial basement membrane dystrophy is unaltered by phototherapeutic keratectomy treatment
- 2014
-
Ingår i: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 55:3, s. 1835-1841
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate the effect of phototherapeutic keratectomy (PTK) treatment on corneal epithelial wing cell and corneal subbasal nerve density in epithelial basement membrane dystrophy (EBMD).METHODS: A total of 39 patients with EBMD who underwent PTK treatment, 40 healthy volunteers, and 24 untreated eyes with EBMD were examined with laser-scanning in vivo confocal microscopy (IVCM). Corneal subbasal nerves and epithelial wing cells were manually quantified from IVCM images by two observers, while epithelial wing cells were additionally quantified by a fully automated method.RESULTS: Subbasal nerve density was significantly reduced in untreated (10,164 ± 4139 μm/mm(2); n = 24) and PTK-treated (10,624 ± 4479 μm/mm(2); n = 39) EBMD eyes, relative to healthy controls (18,241 ± 4479 μm/mm(2); n = 40) (P < 0.001). Subbasal nerve density in PTK-treated and untreated eyes did not differ (P > 0.05). Epithelial wing cell density did not differ between PTK-treated and untreated EBMD eyes, by either manual or automated analysis; however, epithelial wing cell density in PTK-treated EBMD corneas was significantly reduced (P = 0.008) relative to healthy corneas, by automated cell counting.CONCLUSIONS: Subbasal nerve density in EBMD is reduced by 45% and recovers only to the reduced level in the long term after PTK treatment, whereas epithelial wing cell density in EBMD is not affected by PTK in the long term. Fully automated cell analysis from IVCM images could provide an objective, standardized means to quantify and compare corneal cell densities in future studies.
|
|
| 66. |
|
|
| 67. |
|
|
| 68. |
|
|
| 69. |
|
|
| 70. |
|
|
