Wide Corneal Epithelial Thickness Mapping in Eyes With Topical Antiglaucoma Therapy Using Optical Coherence Tomography

PURPOSE: The purpose of this study was to assess the corneal epithelial thickness (CET) of the 9-mm diameter zone in patients treated using topical antiglaucoma medications and to evaluate the factors associated with CET changes. METHODS: Seventy-five patients treated using topical antiglaucoma medications and 65 healthy subjects were included in this cross-sectional study. Each patient completed the Ocular Surface Disease Index (OSDI) questionnaire and underwent examinations including the Schirmer I test, tear breakup time (TBUT), and fluorescein staining. CET mapping of the 9-mm diameter zone was performed using RTVue XR. The CET of the different analyzed zones was compared between groups. The relationship between CET and confounding factors was investigated. RESULTS: The patient group had a significantly shorter TBUT, shorter Schirmer I test, and greater fluorescein staining than those of the control group (all P < 0.05). The mean CET of patients with glaucoma was significantly lower than that of controls in the central, paracentral, mid-peripheral, and peripheral zones (all P < 0.001). Age affected the CET in the paracentral, mid-peripheral, and peripheral zones (all P < 0.01). The number of medications affected the CET in the central, paracentral, and mid-peripheral zones (all P < 0.05). The duration of treatment affected the CET in the central and peripheral zones (all P < 0.05). CONCLUSIONS: Use of topical IOP-lowering medications leads to epithelial thinning in the 9-mm diameter zone in glaucomatous eyes. Epithelial protection should be considered in older patients and patients treated with multiple medications from the early stages of long-term topical antiglaucoma therapy. TRANSLATIONAL RELEVANCE: The 9-mm diameter CET mapping by using widefield optical coherence tomography (OCT) can be a valuable and convenient method to assess the ocular surface damage in patients with topical antiglaucoma therapy.