Abstract
Purpose :
This retrospective longitudinal study investigates the therapeutic impact of recombinant human nerve growth factor (rhNGF) in treating neurotrophic keratitis (NK) by tracking the cell densities of epithelial winged cells (EWC) and epithelial basal cells (EBC) over time in patients diagnosed with NK using in vivo confocal microscopy (IVCM).
Methods :
Ten adult patients diagnosed with NK who had consistent monthly follow-ups at Gavin Herbert Eye Institute, Irvine, were enrolled in the study. Treatment involved the application of topical rhNGF 0.002% 1 drop 6 times a day for 8 weeks. Central corneal images were captured over 12 months using IVCM (HRT 3 RCM, Heidelberg, Germany). EWC and EBC densities were analyzed manually using the ImageJ software (NIH, Bethesda, MD, Fig.1). The changes in cell densities were analyzed longitudinally.
Results :
IVCM images from 10 KM eyes (n=10) were analyzed. Linear interpolation was used to estimate the missing data point. The one-way ANOVA with repeated measures and Geisser-Greenhouse correction revealed statistically significant changes in both EWC and EBC densities over time (p<0.05). Notably, the positive slope in the linear regression for both cell types was statistically significant (p<0.05) indicating a regenerative effect of rhNGF on corneal epithelial cells (Fig. 2).
Conclusions :
This study provides preliminary evidence that rhNGF promotes corneal epithelial cell regeneration in NK. The significant and consistent increase in EWC and EBC densities over the 12-month period objectively characterizes the positive impact of rhNGF on corneal healing. Furthermore, the successful assessment of epithelial cellular densities longitudinally presents IVCM as an emerging non-invasive tool for evaluating corneal cellular changes over time. Further research, including randomized controlled trials with larger sample sizes and control groups, will give more confidence in using rhNGF and IVCM as optimal therapeutic regimens for NK.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.