Abstract
Purpose :
Ocular surface disease (OSD) is prevalent amongst eyes treated with chronic topical antiglaucoma (A/G) therapy.The purpose of this study was to evaluate the density of corneal epithelial cells, presence of epithelial dendritic cells (DC) and sub-basal nerve plexus characteristics in eyes on topical A/G therapy, based on imaging by in vivo confocal microscopy (IVCM).
Methods :
Central corneal images were prospectively captured from 16 eyes of 11 patients on topical A/G therapy (>6 months) and 10 normal control eyes, using IVCM (HRT III RCM, Heildelberg, Germany). Demographic data was collected, as well information on the types and duration A/G therapy. In addition, ocular surface disease index (OSDI) score, density of epithelial wing cells (WC) and basal cells (BC), sub-basal nerve features (density, tortuosity and reflectivity), and presence of DC were all assessed and recorded by trained reading center graders.
Results :
Mean OSDI score was 6.36 ± 6.07 in controls and 30.20 ± 33.75 in glaucoma patients on topical A/G therapy (p=0.05). Nerve fiber density and reflectivity of the sub-basal plexus were significantly lower in eyes on A/G topical therapy as compared with controls (1869.42 ± 785.40 μm/ frame versus 2724.86 ± 687.06 μm/ frame, p-value =0.008 and 2.83 ±0.83 versus 3.50±0.55, p-value = 0.02).Nerve tortuosity was significantly higher in eyes on A/G drops group as compared to controls (2.87 ± 0.57 versus 2.13 ±0.48, p-value=0.003). DC displayed significantly increased density in eyes treated with A/G drops than in controls (72.94± 61.74 cells/mm2 versus 27.53 ±5.58 cells/mm2, p-value =0.01).WC and BC densities were both lower in glaucomatous eyes on A/G drops group as compared with controls; the difference in WC density was not statistically significant (5658.94±654.88 cells/mm2 vs. 5812.62 ±772.74 cells/mm2, p-value = 0.6), while the decrease in BC density in A/G treatment group was statistically significant (6442.75 ±692.55 cells/mm2 vs. 8479.20 ± 833.50 cells/mm2, p-value < 0.001).
Conclusions :
Our study revealed significant microstructural changes in the corneas of eyes treated with topical A/G therapy that is associated with ocular surface disease symptoms. IVCM may be a useful tool for the assessment of the ocular surface toxicity associated with glaucoma topical therapy
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.