Cornea - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - CorneaPresentation Time: 8:30 AM - 10:15 AMObjective Assessment of the Corneal Endothelium in FuchsEndothelial DystrophyJay W. McLaren, Lori A. Bachman, Sanjay V. Patel. Ophthalmology,Mayo Clinic, Rochester, MN.Purpose: Assessment of the corneal endothelium in early stages ofFuchs endothelial dystrophy is subject to sampling errors because ofthe non-uniform distribution of guttae. In this study we developed astandardized method of endothelial assessment and examined thepredictive relationship between the effective endothelial cell density(ECD) and severity of Fuchs dystrophy based on subjective grades.We also examined the relationship between effective ECD andanterior corneal structural changes (backscattered light).Methods: The corneal endothelium of 51 eyes from 30 patients, withvarying degrees of Fuchs endothelial dystrophy, was examined byusing confocal microscopy (ConfoScan 4, Nidek Technologies) witha 20x non-contact objective. In 2 to 3 images that sampled the centralendothelium, local contiguous cell density was determined by using avariable frame method (2 to 177 cells in 1 to 10 patches, dependingon the distribution of guttae). The effective ECD was the product ofthe local cell density and the ratio of the sample area not covered byguttae to total sample area, which was determined by image analysis.The severity of the disease in each eye was assessed during slit-lampexamination by two examiners based on a modified Krachmer grade(1-6). In 55 eyes with Fuchs dystrophy from a second group of 30patients, the clinical grade was predicted from the effective ECD andthe regression coefficients from the first group, and compared to thesubjective clinical grade assigned by one examiner. The relationshipbetween effective ECD and backscatter from the anterior stroma,based on brightness of confocal images (40x objective, ConfoScan 4)in the second group, was examined by Pearson regression.Significance was determined by using generalized estimatingequation models.Results: The effective ECD decreased linearly with subjective grade(r=-0.93, p