Quantitative Regional Differences in Corneal Endothelial Abnormalities in the Central and Peripheral Zones in Fuchs' Endothelial Corneal Dystrophy

PURPOSE. To quantitate the regional corneal differences in endothelial abnormalities in Fuchs' endothelial corneal dystrophy at multiple sites, including the peripheral zone. METHODS. Forty-one eyes of 23 patients with Fuchs' endothelial corneal dystrophy were studied at Osaka University Hospital. The sizes of the areas of degeneration resulting from guttae were measured using a new noncontact specular microscope in the central cornea, the paracentral zone 0.6 mm from the center, and the peripheral zone 3.7 mm peripheral to the center. RESULTS. The percentages of the images covered by the abnormal areas were 71% +/- 36% in the center, 68% +/- 35% in the paracentral zone, and 33% +/- 36% in the peripheral zone. The values in the peripheral zone were significantly (P < 0.001) smaller than in the center and paracentral zones. The percentage of the abnormal area in the peripheral zone was correlated significantly (P < 0.001, R-2 = 0.452) with the disease grade in advanced cases, whereas those in the center or paracentral zones were not. Among the areas of the peripheral zone, the abnormal inferotemporal areas were significantly (P < 0.001) larger than superonasally. CONCLUSIONS. In Fuchs' endothelial corneal dystrophy, the corneal endothelium is damaged more severely in the center and paracentral zones than in the peripheral zone, and peripheral measurement can objectively grade the disease. In the peripheral zones, the inferotemporal endothelium is damaged more severely. These findings might provide a new understanding of the disease mechanisms.