Corneal Thickness and Corneal Volume Measurement in Keratoconic Eyes Using the Pentacam System

Purpose: To evaluate the Pentacam system as a new tool to study the corneal thickness spatial profile and corneal volume distribution in keratoconic Eyes. Setting: EL Rowad Eye Hospital, Giza, Egypt. Methods: 24 normal eyes for 12 patients and 29 eyes for 20 patients diagnosed as keratoconus based on classic corneal topographic and clinical findings, were included in the study. All eyes were examined using the Pentacam Comperhensive Eye Scanner (CES) at El Rowad eye Hospital, Giza, Egypt. In this study Pentacam used to asses corneal thickness profile and percentage of thickness increase from the central thinnest point to the periphery. Corneal thickness values at the thinnest point were recorded for each eye. The Pentacam record the average thickness values of the points on 22 imaginary circles centered on the thinnest point with increased diameters of 0.4 mm steps. The corneal thickness at 2, 4, 6, 8, 10 mm circle diameter were recorded in this study. Corneal volume evalu- ated, the total corneal volume and corneal volume at 3, 5, 7 mm diameter. Results: Statistically significant differences were found in all positions of the corneal thickness spatial profile between the control group and keratoconus group (p 0.01). Eyes with keratocnous had much thinner values. Significant differences were found in all percentage increases in thickness between the control group and keratoconus group (p 0.01). The percentage thickness increase from thinnest point to the periphery was much higher in keratoconic corneas. Statistically significant differences were found in all positions of corneal volume distribution between the control group and keratoconus group (p 0.01). Keratoconic corneas had much less volume. Conclusion: Corneal thickness spatial profile, corneal volume distribution, and percemtage increase in corneal thickness were different between keratoconic eyes and normal eye. Further studies are necessary to use the pentacam to find pathognocmic value could diagnose early and fruste form keratoconus.