Comparing structural and vascular parameters between healthy eyes and eyes with primary angle-closure disease

To compare structural and vascular parameters between healthy control eyes and eyes with primary angle-closure suspect (PACS), Primary angle-closure (PAC), and primary angle-closure glaucoma (PACG). Thirty control, 30 PACS, 31 PAC, and 31 PACG eyes were enrolled in this cross-sectional investigation. In addition to demographic and ocular evaluations, the measurements of circumpapillary retinal nerve fiber layer (cpRNFL), ganglion cell complex (GCC), and vessel densities (VD) in the radial peripapillary capillary (RPC) and superficial capillary plexus (SCP) were conducted for all eyes. Generalized estimating equations were used for the analysis. The Sidak method was applied for pairwise comparison. The median (IQR) age in the entire group was 58 (51 to 62) years, and 62.5% (40) of the subjects were female. The PACG eyes had the thinnest cpRNFL and GCC and the lowest VD in the circumpapillary and macular area compared to the control and PACS groups (p < 0.05). The structural parameters were comparable between the PAC and PACS and control groups. The PAC eyes had lower VD in the inferotemporal, inferonasal, and nasal inferior sectors of the RPC compared to the control or PACS group. Also, the VD in the macular whole image, the average parafoveal VD, and the VD in the superior quadrants of both the parafovea and perifovea were lower than those of the control group (P < 0.05). Compared to the PACS and control groups, the PAC eyes had lower VD in some sectors of RPC and SCP. This supports the possibility that, within the spectrum of primary angle-closure disease, retinal microvascular loss may occur earlier than structural deterioration.