Optical Microangiography and Progressive Retinal Nerve Fiber Layer Loss in Primary Angle-closure Glaucoma

Abstract

Precis Younger patient age (coefficient: 0.10, P=0.04) and greater peak IOP during follow-up (coefficient: -0.14, P=0.03), but not baseline optical microangiography parameters, were significantly associated with a faster rate of RNFL loss in mild-moderate PACG. Purpose: To evaluate the association between optical microangiography (OMAG) measurements and progressive retinal nerve fiber layer (RNFL) loss in primary angle-closure glaucoma (PACG). Methods: In a prospective study, 45 eyes of 30 PACG patients (86 hemifields) with mild to moderate functional damage were longitudinally studied for at least 2 years and with a minimum of 3 optical coherence tomography (OCT) examinations. OMAG imaging was performed at the baseline visit. Effect of clinical parameters (age, gender, presence of systemic diseases, central corneal thickness, mean, peak and fluctuation of intraocular pressure during follow-up), baseline hemifield mean deviation (MD) and baseline OMAG (quadrant peripapillary and macular perfusion density [PD]) on the rate of RNFL change was evaluated using linear mixed models. Results: Average (±SD) hemifield MD, RNFL thickness, peripapillary PD and macular PD of the analyzed quadrants at baseline were -6.0±3.4 dB, 89±21 µm, 40.1±3.5% and 29.6±10.3%, respectively. Rate of quadrant RNFL change was -2.5±1.7 µm/year. Multivariate mixed models showed that younger patient age (coefficient: 0.10, P=0.04) and higher peak IOP during follow-up (coefficient: -0.14, P=0.03) were significantly associated with a faster rate of RNFL loss. Conclusions: Younger patient age and greater peak IOP during follow-up were significantly associated with a faster rate of RNFL loss in PACG patients with mild to moderate severity of functional damage. None of the OMAG parameters at baseline were associated with RNFL thinning suggesting a limited role of OCTA imaging in predicting structural progression in mild-moderate PACG.