Abstract
Purpose
To assess if polymegethism and pleomorphism were evident in corneal endothelium after medium-term rigid gas permeable (RGP) contact lens wear.
Methods
In a cross-sectional observational study over 12 years, single images of the central region of the corneal endothelium of one eye of 46 subjects were taken with a non-contact specular microscope, along with a measure of central corneal thickness (CCT). The images were printed onto A3-sized paper and 100 cells/image measured by planimetry.
Results
Subjects aged between 20 and 32 years, with an average cumulative RGP wear of 6.0 +/- 1.6 years (range 3–9 years) were assessed; 26 of the subjects were Caucasian and 20 were Asian. The mean CCT was 0.515 +/- 0.027 mm. The group cell area value was 401 +/- 42 sq micron to give an estimated endothelial cell density (ECD) of 2520 +/- 273 cells/sq mm. As compared to a historical database, most endothelia (37/46) showed some changes with the mean coefficient of variation on cell area (COV) being 36.7 +/- 8.0% and the percentage of 6-sided (HEX) being 51.8 +/- 8.8%. There were modest correlations between years of RGP wear and both COV (p = 0.009, r spearman = 0.424) and HEX (p = 0.025, r spearman = -0.291), but not for ECD or CCT.
Conclusions
Corneal endothelial polymegethism appears to be a commonplace consequence of RGP lens wear with the magnitude of the change being related to the cumulative duration of the lens wear.
To assess if polymegethism and pleomorphism were evident in corneal endothelium after medium-term rigid gas permeable (RGP) contact lens wear.
Methods
In a cross-sectional observational study over 12 years, single images of the central region of the corneal endothelium of one eye of 46 subjects were taken with a non-contact specular microscope, along with a measure of central corneal thickness (CCT). The images were printed onto A3-sized paper and 100 cells/image measured by planimetry.
Results
Subjects aged between 20 and 32 years, with an average cumulative RGP wear of 6.0 +/- 1.6 years (range 3–9 years) were assessed; 26 of the subjects were Caucasian and 20 were Asian. The mean CCT was 0.515 +/- 0.027 mm. The group cell area value was 401 +/- 42 sq micron to give an estimated endothelial cell density (ECD) of 2520 +/- 273 cells/sq mm. As compared to a historical database, most endothelia (37/46) showed some changes with the mean coefficient of variation on cell area (COV) being 36.7 +/- 8.0% and the percentage of 6-sided (HEX) being 51.8 +/- 8.8%. There were modest correlations between years of RGP wear and both COV (p = 0.009, r spearman = 0.424) and HEX (p = 0.025, r spearman = -0.291), but not for ECD or CCT.
Conclusions
Corneal endothelial polymegethism appears to be a commonplace consequence of RGP lens wear with the magnitude of the change being related to the cumulative duration of the lens wear.
| Original language | English |
|---|---|
| Pages (from-to) | 109-115 |
| Number of pages | 7 |
| Journal | Contact Lens and Anterior Eye |
| Volume | 40 |
| Issue number | 2 |
| Early online date | 13 Dec 2016 |
| DOIs | |
| Publication status | Published - 1 Apr 2017 |
Keywords
- corneal epithelium
- ophthalmology
- vision sciences