Long-term optic nerve head microvascular impairment after acute primary angle closure: an OCTA study

While previous studies documented transient reductions in fundus vessel density (VD) following acute primary angle closure (APAC), we investigated whether optic nerve head (ONH) and macular VD was lower long-term following APAC. The study aimed to describe long-term microvascular patterns after APAC and identify anatomical regions showing lower VD.

Resolved APAC, primary angle closure suspects (PACS), and age-sex-matched healthy controls were enrolled. Quantitative microvascular assessment was performed using spectral domain optical coherence tomography angiography (OCTA) system (RTvue XR Avanti; Optovue, Fremont, CA, USA), with 4.5*4.5 mm ONH and 3.0*3.0 mm macular scan protocols. Peripapillary VD was analyzed as the primary endpoint, while sectoral ONH VD and macular VD were evaluated as secondary measures.

The median and range of interval between APAC onset and examination was 15, (1, 60) months. APAC eyes demonstrated marked reduction in peripapillary VD compared with PACS and controls. Macular VD was less affected. ONH VD positively correlated with structural parameters in APAC eyes.

Despite clinical resolution of APAC, peripapillary VD was lower in eyes with previous APAC compared with PACS and controls.