Pore Shape Variation in Glaucomatous Lamina Cribrosa

Abstract

Purpose : The lamina cribrosa (LC) is considered to play an important role in the pathogenesis of glaucoma. In this study, we investigate the shape variation (SV) of the LC pores as a potential biomarker for quantifying the morphological irregularity in vivo.

Methods : 36 healthy and 14 glaucomatous (GL) eyes (total: 39 subjects) underwent a comprehensive ophthalmic examination and scanning of the optic nerve head with swept-source OCT (Table 1). Images were converted to isotropic and pores were segmented using ImageJ. SV was defined as the mean-squared error of the pore pattern with respect to a solid circle (Figure 1(a)) with SV of a circle marked as zero, and higher SV value with increasing shape irregularity. SV of each pore was automatically calculated by a MATLAB code. The overall SV value was generated as the average of SV in the stack of individual slices. Age effect on SV was examined in all healthy eyes and a subset of 14 eyes was selected for age-matched comparison with the glaucomatous eyes (Table 1).

Results : No significant correlation was detected between SV and age (p=0.145; Spearman correlation) in all healthy subjects. Examining the effect of depth on the difference between SV of glaucomatous and healthy eyes, the posterior third of the LC had significantly lower than other sections (p=0.007; Figure 1(b)). SV in glaucoma eyes was significantly higher than in the healthy group (p=0.008; Figure 1(c)).

Conclusions : We demonstrated morphological differences in pore shape variation between healthy and glaucoma eyes that is mostly affecting the anterior 2/3 of the LC. Further studies are warranted to assess the use of SV as a structural biomarker in glaucoma.

This is a 2021 ARVO Annual Meeting abstract.

 

Fig. 1. (a) Shape variation. Shape variation changes by (b) LC depth (36 eyes) and (c) diagnosis (14 eyes).