Longitudinal evaluation of macular vascular density alterations in unilateral amblyopic children undergoing therapy: An optical coherence tomographic angiography study

Importance: Understanding the pathophysiology of the macula in amblyopic eyes is an active research area. Objective: To correlate macular retinal vascular density changes with best-corrected visual acuity changes following occlusion therapy for amblyopia in children. Design: A prospective cohort study of children visiting the Pediatric Ophthalmology Division of our institution between January 2020 and January 2022 was conducted. Setting: A specialist eye hospital in Saudi Arabia. Participants: Thirty children with unilateral amblyopia. Exposure: Occlusion therapy for amblyopia. Main Outcome and Measures: Best corrected visual acuity (logMAR) before and at each of the four optical coherence tomographic angiographies was compared in amblyopic and fellow eyes. The effect of pretreatment determinants on the correlation between best-corrected visual acuity and retinal vascular density changes was reviewed. Results: In this cohort of 30 amblyopic and 30 fellow eyes from 30 children (mean age 8.7 +/- 1.4 years; male: female 18:12. The best-corrected visual acuity improved from a median of 0.6 (interquartile range 0.5; 1.1) pretreatment to a median of 0.4 (interquartile range 0.2; 0.6) posttreatment in amblyopic eyes, and from a median of 0.1 to 0.05 in the fellow eyes. The total percentage change in retinal vascular density in the amblyopic eye was significantly higher than that in the fellow eye (Z = -1.92, P = 0.05). The change in best-corrected visual acuity in the amblyopic eye after a median of 98 months (interquartile range, 69-126 months) of intervention was significantly correlated with the refraction-adjusted change in retinal vascular density (B = -0.03, 95 % confidence interval -0.04, -0.02, P < 0.001) and was influenced by strabismus (B = -0.46, 95 % confidence interval -0.59, -0.34, P < 0.001), type of amblyopia (B = 0.24, 95 % confidence interval 0.12, 0.36, P < 0.001), duration of occlusion (B = -0.43, 95 % confidence interval -0.65, -0.22, P < 0.001), and occlusion compliance (B = 0.24, 95 % confidence interval 0.11, 0.36, P < 0.001). Conclusions: and Relevance: The RVD in amblyopic eyes in the first six months of therapy was significantly lower than that in fellow eyes, but not in subsequent assessments.