Comparison of structural and functional features in primary angle closure and open-angle glaucoma
Reviewed by Su Young

In this large cross-sectional study, differences in structural and functional damage were assessed among patients with primary open-angle glaucoma (POAG) and primary angle closure glaucoma (PACG) with optical coherence tomography and reliable visual field testing. Two-hundred and eighty-three patients with PACG and 4110 patients with POAG were included. Despite similar mean deviation on visual fields (mean [SD] –7.73 [7.92] vs. –7.53 [6.90]dB, p=0.72), patients with PACG had thicker global retinal nerve fibre layer (RNFL), smaller cup volume, smaller cup-to-disc ratio, and larger rim area than POAG (77 [20] vs. 71 [14]µm, 0.32 [0.28] vs. 0.40 [0.29]mm3, 0.6 [0.2] vs. 0.7 [0.1], 1.07 [0.40] vs. 0.89 [0.30]mm2, p<0.001 for all), while patients with POAG had more pronounced inferior RNFL thinning (82 [24] vs. 95 [35]µm, p<0.001). Using multivariable analysis, hyperopia [odds ratio (OR): 1.24, confidence interval (CI): 1.13–1.37], smaller cup-to-disc ratio (OR: 0.69, CI: 0.61–0.78), thicker inferior RNFL (OR: 1.15, CI: 1.06–1.26) and worse mean deviation (OR: 0.95, CI: 0.92–0.98) were associated with PACG. Functionally, POAG was associated with superior paracentral loss and PACG with inferior field loss. After adjusting for average RNFL thickness, PACG was associated with more diffuse loss than POAG (total deviation differences 1.26–3.2dB). The study concludes that patients with PACG had less structural damage than patients with POAG despite similar degrees of functional loss. Regional differences in patterns of functional and structural loss between POAG and PACG may improve disease monitoring for these glaucoma subtypes.

Comparison of structural and functional features in primary angle closure and open angle glaucomas.
Sun JA, Yuan M, Johnson GE, et al.
JOURNAL OF GLAUCOMA
2024;33(4):254–61.