To measure corneal epithelial thickness (CET) in patients with glaucoma using anterior-segment optical coherence tomography and to evaluate CET changes in relation to corneal epithelial microvilli analyzed by scanning electron microscopy (SEM).
Twenty-two eyes (16 patients) being treated with preservative-containing topical medications and 12 normal eyes underwent anterior-segment optical coherence tomography imaging using RTVue-100. The CET maps generated corresponded to a 6-mm diameter area of cornea that was divided into 17 sectors. We compared the CETs of each sector obtained in the glaucomatous group with those obtained in the control group.
Glaucomatous eyes were divided into 2 groups based on the number of microvilli on SEM: group 1 (6 eyes) = grades 1 and 2 at SEM (range: 500–3000) and group 2 (10 eyes) = grades 3 and 4 at SEM (range: 0–500). Four CET sectors were significantly thinner in group 1 than in normal eyes: central (P = 0.012), superior (P = 0.005), temporal paracentral (P = 0.003), and temporal midperipheral (P = 0.023). No significant differences were observed between group 2 and normal eyes. CET sectors were significantly thinner in group 1 than in group 2 only in the superior (P = 0.024) and superior-temporal paracentral (P = 0.020) sectors. CET progressively increased in patients with glaucoma as the number of corneal epithelial microvilli decreased.
CET and corneal epithelial microvilli are new parameters with which to evaluate early stages of corneal epithelial changes during glaucoma therapy. In advanced stages of corneal epithelial damage, SEM evaluation reveals ultrastructural epithelial changes that may not be observed on CET measurements.
*Department of Public Health, University of Naples “Federico II,” Naples, Italy;
†Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples “Federico II,” Naples, Italy; and
‡Interdepartmental Electron Microscope Centre, University of Naples “Federico II,” Naples, Italy.
Correspondence: Gilda Cennamo, MD, Department of Public Health, University Federico II, University of Naples Federico II, Via S. Pansini 5, Naples 80133, Italy (e-mail: firstname.lastname@example.org).
The authors have no funding or conflicts of interest to disclose.
Received February 15, 2018
Received in revised form July 23, 2018
Accepted July 28, 2018