Abstract
Purpose :
Primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) have distinct disease mechanisms and clinical manifestations. We evaluated structural and functional damage in a large dataset of PACG and POAG patients, to better characterize the two glaucoma subtypes.
Methods :
In this cross-sectional study, ICD-10 diagnosis codes were used to identify PACG and POAG patients at an academic center. Optical coherence tomography (OCT) images (signal strength ≥ 6) of the peripapillary retinal nerve fiber layer (RNFL) and reliable Humphrey visual field (VF) testing within 30 days of OCT were included. Demographic and ophthalmic information was obtained from medical records. Multivariable logistic regression using Bayesian information criteria was used to determine optimal structural and functional parameters independently correlated with PACG. Total deviation differences at 52 VF locations between POAG and PACG were also assessed.
Results :
283 PACG and 4110 POAG patients were included. They did not differ in ethnicity (p = 0.18) although PACG patients were younger, more were female, and more hyperopic (67 years vs 69 years, p = 0.03; 62% vs 52%, p = 0.002; +0.29 D vs –0.96 D, p < 0.001). Despite similar mean deviation values on Humphrey VF (–7.73 dB vs –7.53 dB, p = 0.67), PACG eyes demonstrated thicker average RNFL, smaller cup volume and cup-to-disc ratio (CDR), and larger rim area than POAG eyes, while POAG eyes showed more pronounced inferotemporal RNFL thinning (Table 1). In a multivariate analysis of 1769 patients (90 PACG and 1679 POAG), hyperopia, smaller CDR, and thicker inferior RNFL were significantly associated with PACG (p ≤ 0.001 for all). Functional differences on VF were noted after adjusting for RNFL thickness: POAG was associated with superior paracentral loss, and PACG with inferior arcuate loss (Figure 1).
Conclusions :
This large cross-sectional study confirms gender and refractive differences between POAG and PACG. Novel findings include more pronounced inferotemporal RNFL thinning in POAG with superior paracentral VF loss, while PACG has thicker average RNFL and more inferior arcuate VF loss. Understanding the structural and functional differences between POAG and PACG may aid in disease diagnosis and monitoring.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.