Comparison of automated and manual measurements of corneal epithelial thickness in eyes with limbal stem cell deficiency.

Abstract

Purpose : To compare the outcomes of manual and automated corneal epithelial thickness (CET) assessments from AS-OCT.

Methods : Eight-seven eyes from 64 LSCD individuals and 65 eyes from 39 healthy subjects were included in this cross-sectional study. OCT images of corneas were acquired using a Fourier-domain AS-OCT (Optovue, Inc). The automated measurement of CET was obtained using the manufacturer’s program and by manual measurement. The average CET was obtained from three consecutive epithelial profile maps. The average CET of manual measurement was obtained from three consecutive cross-line scans using 3-point measurement as previously described.

Results : The central corneal epithelial thickness was thinner in LSCD patients compared to healthy individuals by both manual and automated measurements. Furthermore, epithelial profile maps revealed thicker CET than manual assessment. Manual measurement of CET in LSCD was significantly lower than the automated measurement (39.8±11 um vs. 48.8±7.2 um, p < 0.001, 95%CI -11.0 to -6.9). However, there was no significant difference in the CET of healthy controls between the two measurement techniques. In addition, the correlation between two measurements was 0.797 in the healthy group and 0.497 in the LSCD group. The correlations between the automated and manual measurements in the mild, moderate, and severe stage of LSCD were 0.623, 0.632, and 0.378, respectively

Conclusions : There is discrepancy between the manual and automated measurements in eyes with LSCD but not in normal eyes. Automated measurements in LSCD exhibited a higher rate of errors and non-uniform measurements. Automated CET measurements are unreliable in eyes with advance stage of LSCD.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.