Comparison of Lamina Cribrosa Curvature in Pseudoexfoliation and Primary Open-Angle Glaucoma

Abstract

To compare lamina cribrosa curvature (LCC) in pseudoexfoliation glaucoma (PXG) and primary open-angle glaucoma (POAG) and to elucidate the factors associated with LCC in both groups. Retrospective, cross-sectional study. Forty eyes with PXG and visual field mean deviation-matched 40 eyes with POAG were included. Spectral domain optical coherence tomography enhanced depth imaging was used to acquire LC images. The LCC index (LCCI) was calculated as LCC depth/LCC width× 100. Calculated LCCI values were compared between the PXG and POAG groups. Logistic regression analysis was performed to investigate the factors related to the presence of PXG. Factors associated with LCCI were determined by uni- and multivariable linear regression analyses in both groups. Visual field mean deviation (-11.7 ± 9.7 dB vs-1.0 ± 8.5 dB, P= .731) and retinal nerve fiber thickness (647.4 ± 22.7μm vs 68.3 ± 19.9μm, P= .857) did not differ between the 2 groups. However, the mean (8.8 ± 2.9 in PXG, 6.6 ± 1.9 in POAG) and sectoral LCCIs assessed at 0, 30, 60, 90, and 120° were significantly greater in the PXG than in the POAG group (all, P < .05), but not at 150° (P= .113). Logistic regression analysis revealed that higher average LCCI (odds ratio [OR]= 1.509 [95% confidence interval 1.180-2.047], P= .003) and older age (OR= 1.074 [95% confidence interval 1.017-1.147], P= .019) were associated with the presence of PXG. IOP was associated with mean LCCI only in the POAG group (β= 0.150 [95% confidence interval 0.018-0.281], P= .027) while none of the factors showed association with LCCI in PXG. PXG eyes had more steeply curved LC than POAG eyes with a similar level of glaucoma severity. The clinical implication(s) of steeper LCC in PXG should be investigated in a forthcoming study.