Клинический профиль и демографическое распределение периферической прозрачной дегенерации роговицы в Индии: исследование 559 пациентов

Clinical profile and demographic distribution of pellucid marginal corneal degeneration in India: A study of 559 patients.

Pellucid marginal corneal degeneration (PMD) is a progressive, noninflammatory ectatic corneal disorder that more commonly involves the inferior cornea separated from the limbus by a relatively uninvolved area of 1 to 2 mm in width.[¹] The term pellucid meaning “clear” to denote the corneal clarity was used for the first time by Schlaeppi.[²] The corneal area between the thinned band-like region and the limbus is characterized by the absence of lipid deposition, scarring, or vascularization and is typically epithelialized. The degree of thinning of the cornea can be severe resulting in up to 80% stromal tissue loss.[³] This “beer belly” configuration causes the cornea superior to the ectasia to protrude and produces a flat vertical meridian above the thinning and a high against-the-rule astigmatism. The corneal protrusion is more marked just superior to the area of thinning where the thickness of the cornea is usually normal.[⁴,⁵] While the classic presentation of the disease is inferior thinning, there are reports with involvement of the superior, temporal, and nasal parts of the cornea.[⁶,⁷,⁸,⁹]