Abstract
Purpose :
To evaluate corneal sensation and characterize subbasal nerve plexus in eyes with limbal stem cell deficiency (LSCD)
Methods :
This prospective cross-sectional comparative study was approved by the Institutional Research Boards and adherent to the Declaration of Helsinki. Forty-six eyes (35 subjects) with LSCD and 14 normal control eyes (14 subjects) were recruited between 2019-2022. The central corneal sensation was measured by Cochet-Bonnet esthesiometer and subbasal nerve plexus was imaged at the central cornea and 4 limbal regions (superior, inferior, nasal and temporal) using in vivo confocal microscopy. Characteristics of subbasal nerve plexus namely subbasal nerve density (SND) and subbasal nerve branch density (SNBD) were quantified using CCMetrics (M.A. Dabbah, Imaging Science, University of Manchester) by 2 masked examiners. The severity of LSCD was graded using a previously published composite grading system. A composite score of <5 was defined as stage I, between 5-9 as stage II and ≥10 as stage III LSCD. Statistical analyses were performed using the Kruskal-Wallis test and Pearson correlation.
Results :
Seven, 18 and 21 eyes were classified as stage I, II and III LSCD, respectively. The mean sensation (mm±SD) at the central cornea and limbus were 29.2±21.5 and 33.5±15.1 in the LSCD group and 57.6±5.8 and 54.3±4.7 in the control group (all p<0.001), respectively. All parameters of subbasal nerve plexus were significantly decreased at the central and limbal regions in the LSCD group compared to the control (p<0.05). The central corneal sensation had moderate negative correlation with the LSCD composite scores (r=-0.64), p<0.001) and had moderate positive correlation with SND (r=0.63, p<0.001) and SNBD (r=0.57, p<0.001).
Conclusions :
Corneal sensation, SND, and SNBD were reduced in LSCD at the both central cornea and limbal regions, and the degree of reduction positively correlates with the severity of LSCD. This study demonstrates the first time the co-existence of neurotropic element in the pathophysiology of LSCD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.