Variation in Central and Vertical Corneal Endothelial Cell Density in Normal Subjects

Abstract

Twenty normal subjects, aged 20 to 50, who had never worn contact lenses underwent determinations of central, inferior and superior corneal endothelial cell density using the Heyer-Schulte specular microscope. Analysis of variance revealed that superior cell density was significantly larger than central cell density, and that central cell density was significantly larger than inferior cell density (P less than 0.00001). In addition, 4 of these subjects had measurements taken on 4 separate sessions. Analysis of variance revealed that central and vertical cell density determinations were reproducible across measurement sessions. The finding of a vertical gradient in cell density was in contrast to 2 published reports which found no vertical differences in the normal cornea. Consequently, those data were re-analyzed using correct statistical procedures and similar vertical differences were obtained for one series of patients. The finding of a vertical gradient in endothelial cell density challenges the appropriateness of relying upon measurement of the central corneal field as an indicator of the pre-operative endothelial cell density.

Identifying relationships between tomography-derived corneal thickness, curvature, and diameter and in vivo confocal microscopic assessment of the endothelium in healthy corneas of young adults

“…[15][16][17][18][19][20] When compared with mean ECD values reported for children (3400-4300 cells/mm 2 ) and for elderly eyes (2324-3175 cells/mm 2 ), a clear trend of decreasing mean ECD with advancing age is observed. [9][10][11]15,17,[21][22][23][24][25] Consistent with the majority of other published reports, there was no significant difference in mean ECD based on gender in this study. 5,9,16,17,26,27 With regards to the reliability and repeatability of the NAVIS endothelial analysis system, automated endothelial analysis often fails to correctly identify endothelial cell borders.…”