A Case of Unilateral Pellucid Marginal Corneal Degeneration Diagnosed by Computerized Topography

Lee, Yong Bum; Tchah, Hungwon

Abstract

Pellucid marginal degeneration is a noninflammatory peripheral corneal thining disorder, which progresses slowly, affects inferior cornea bilaterally, occurs usually between twenties and fifties. Protrusion of the cornea with normal corneral thickness occurs above a band of thinning which is located 1 to 2mm from the limbus and measures 1 to 2mm in width and the patient complaints of progressive visual disturbance due to high irregular astigmatism. Topographically, the lowest corneal power is located along a narrow corridor of the central and peracental cornea and corneal power is highest along the inferior peripheral cornea and in the mid-peripheral cornea along the inferior oblique corneal meridian in a band-like fashion and is decreased slowly superior to that meridian. We experienced a case of pellucid marginal degeneration who had a history of progressive visual loss due to high irregular astigmatism. A 67 year-old woman had the characteristic topographic pattern and clinical feature of pellucid marginal degeneration only in her righ eye and we report it as the first case of unilateral pellucid marginal degeneration in Korea.