Peripheral hypertrophic subepithelial corneal degeneration presenting with bilateral nasal and temporal corneal changes.

Abstract

To characterise the history, clinical and histopathological features of patients with bilateral nasal and temporal peripheral hypertrophic subepithelial corneal degeneration in a German population. A detailed ophthalmological and dermatological history and clinical findings were recorded of nine patients with bilateral simultaneous nasal and temporal peripheral corneal degeneration from two centers in Germany. Excised tissues were studied by histopathology, immunohistochemistry, and transmission electron microscopy. Foreign body sensation and need of artificial tear substitutes were the only symptoms reported regularly. Schirmer's and Jones-test were normal in all, but fluorescein break-up time of >10 s was found in five eyes of four patients. Best corrected visual acuity was reduced only under glare conditions. Corneal topography revealed irregular astigmatism in 13 of 14 eyes. Follow-up median time was 35 months. Most cases were stable within the follow-up period. Light and electron microscopy revealed the findings of superficial vascularised corneal hypertrophic scars, oxytatlan fibers, and discontinued Bowmans layer. In this series of German patients with peripheral hypertrophic subepithelial corneal degeneration, the changes were predominantly located in the palpebral aperture and often present in both eyes. No associated surface disease could be established in this study. Light and transmission electron microscopy showed histological features that are similar to Salzmann's corneal changes without any inflammation. We hypothesise that light exposure and a localised limbal insufficiency could be involved in the pathogenesis.