Regional Variations in Corneal Epithelial Cell Density and Morphology Assessed Using In Vivo Confocal Microscopy

Abstract

Aim: To characterize the regional variations in corneal epithelial cell density and morphology using in vivo confocal microscopy (IVCM). Methods: Corneal imaging (IVCM) at 10 locations was performed; corneal apex (i.e., the center), immediately anterior to the corneal nerve whorl (i.e., slightly inferior to the apex), and four quadrants (superior, nasal, inferior, and temporal) both at 1.5 mm and 4.5 mm from the corneal apex (corresponding to 3 mm central and 9 mm peripheral diameter rings). The data of 21 young adults, aged 18 to 35 years, were analyzed. Cell morphometric parameters, including cell density, area, perimeter, Feret diameter, and circularity, were measured for basal and wing cells using Image J software. Results: There was a significant difference in basal cell density (BCD) (P<0.001) and wing cell density (WCD) (P<0.001) for different corneal locations. The BCD (mean±SD: 8,839±416 cells/mm2) and WCD (mean±SD: 5,932±310 cells/mm2) were highest at the corneal nerve whorl compared with all other corneal locations. There were significant differences in wing cell area (P<0.001), perimeter (P<0.001), Feret diameter (P<0.001), and circularity (P<0.001) at varying corneal locations. Conclusion: There are significant regional variations in corneal epithelial cell density and morphology. The BCD and WCD was highest anterior to the corneal nerve whorl.