Climatic proteoglycan stromal keratopathy, a new corneal degeneration

To characterize a previously undescribed corneal disorder, climatic proteoglycan stromal keratopathy.

We prospectively characterized the disorder in 58 eyes of 29 patients (ages 41 to 84 years) at the El Maghraby Eye Hospital, Jeddah Saudi Arabia. Light and transmission electron microscopy were performed on six corneal specimens.

Clinical criteria for the diagnosis included a central, horizontally oval, corneal stromal haze with a ground glass appearance, a uniform or lamellar pattern, greater extent anteriorly and involvement of 50% to 100% of stromal thickness. It occurred bilaterally but sometimes asymmetrically. Density varied from mild to moderate and seldom decreased visual acuity. Sixteen (28%) of 58 corneas had additional degenerative lesions (spheroidal degeneration, mild calcific band keratopathy, and Salzmann's nodular degeneration). Refractile stromal lines or posterior white dots were present in six (10%) of 58 eyes. Videokeratography in 11 (29%) of 38 eyes demonstrated flat areas that overlay the stromal haze. Pathologic analysis demonstrated focal intracellular and extracellular deposits of excess proteoglycans. One specimen showed amyloid. We postulate that climatic factors play a pathogenic role because the disorder occurs in individuals who were exposed to the sunny, dry, dusty environment of the Middle East and because other corneal degenerative disorders were present concomitantly.

Climatic proteoglycan stromal keratopathy is a corneal degeneration that appears as an oval, central, gray, ground-glass haze associated with central corneal flattening on videokeratography and as excess proteoglycans on histologic examination. It seldom severely decreases visual function.