[Corneal topography of the partner eye in unilateral keratoconus]

To study the incidence and shape of subclinical keratoconus with corneal topography in the fellow eye in the case of clinically, slit-lamp biomicroscopically and topographically diagnosed unilateral disease.

Eighty patients with keratoconus were fitted with contact lenses. Twelve of them revealed clinical features of unilateral disease. In these patients we performed a computed topographic analysis in the clinically normal fellow eye. We measured quantitative parameters (central corneal power, I-S value) and qualitative parameters (localization and shape of corneal steepening).

In all 12 patients we found in the fellow eye no slit-lamp evidence for keratoconus. Nine patients were emmetropic in the fellow eye, three patients myopic between -1.5 and -4.0 D. The myopia in these patients was corrected with contact lenses and the investigation was performed 5 days after discontinuance of contact lenses. The corneal topography showed the typical keratoconus pattern in 11 patients with a steepening of the inferior cornea and in 1 case a superior steepening of the cornea; range of I-S values -1.0 to +5.0 D. All patients revealed a configuration of oval type cone keratoconus in the corneal topography.

Keratoconus occurs with a high degree of bilaterality, but with onset of the disease at different times in the two eyes. Corneal topography seems to be a sufficient method to detect early keratoconus.