Peripapillary capillary density in acute angle closure crisis and angle closure suspect: A structure, flow and function correlation study

Purpose: to describe peripapillary vascular changes using Optical Coherence Tomography Angiography (OCT-A) in patients with acute angle closure crisis (AACC) and primary-angle closure-suspects (PACS) in comparison to normal controls. Methods: This cross-sectional/case-control/non-randomized study was conducted at Cairo University Hospitals. It included 21 eyes following AACC, 21 eyes of PACS and 32 eyes of age-matched-controls. Participants underwent visual field (VF) examination, retinal nerve fiber layer (RNFL) assessment using spectral-domain-OCT (SD-OCT), and radial peripapillary capillary density (RPC%) using OCT-A. Results: There was a statistically significant difference in MD and PSD among the three groups ( p ⩽ 0.001). There was a significant difference in mean RNFL among the three groups ( p ⩽ 0.001), this decrease was still present when comparing the AACC group to controls p = 0.032. There was a significant decrease in the peripapillary RPC% in all groups p ⩽ 0.001. The correlation between structure, function and flow was studied for all groups. Peripapillary RPC% in AACC was positively correlated to MD and peripapillary RNFL ( p ⩽ 0.001). In PACS, RPC% was positively correlated to RNFL ( p = 0.012). In controls, RPC% was positively correlated to PSD and peripapillary RNFL ( p ⩽ 0.001). AUC was 0.8 for the MD, 0.56 for the RPC and 0.38 for the RNFL Conclusions: Peripapillary vessel density was lower in AACC eyes than in suspects and control eyes. OCT-A parameters could be a more sensitive marker than OCT parameters after an AACC attack as evident on ROC analysis. PACS remains a clinical diagnosis as we could not find any significant differences in OCT or OCT-A parameters between suspects and normal healthy controls.