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

Abstract

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.

Keywords: Amblyopia; OCTA; Occlusion therapy; Retinal vascular density; Vision recovery.

Fig. 1

Retinal vascular density in amblyopic and fellow eyes. Panel A displays an Optical Coherence Tomography Angiography (OCTA) scan of the macula in an amblyopic eye. The image reveals reduced retinal vascular density (RVD) in comparison to the fellow eye. The OCTA scan shows thinner and fewer blood vessels in the macular region, which is indicative of impaired blood flow and structural anomalies commonly associated with amblyopia. The detailed view provided by the OCTA scan emphasizes areas of decreased perfusion, highlighting the vascular changes occurring in the amblyopic eye. Panel B displays an OCTA scan of the macula in the fellow non-amblyopic eye, which serves as a control. The image exhibits a normal distribution and density of retinal blood vessels, reflecting typical macular perfusion. The contrast between the vascular density in the amblyopic and non-amblyopic eyes is evident, emphasizing the vascular deficits present in the amblyopic eye.

Fig. 2

Scatter plot of changes in retinal vascular density and visual acuity.Panel A examines the relationship between changes in best-corrected visual acuity (measured in logMAR) and changes in retinal vascular density (RVD) in amblyopic eyes. The scatter plot depicts a positive correlation, indicating that improvements in visual acuity are accompanied by increases in retinal vascular density. Panel B displays the relationship between alterations in visual acuity (measured in logMAR) and changes in retinal vascular diameter (RVD) in the fellow, non-amblyopic eye. The scatter plot suggests a modest association, with little fluctuation in visual acuity and RVD. The x-axis denotes the change in best-corrected visual acuity (logMAR) at 4th follow up compared to that before amblyopia therapy. The y-axis denotes the percentage change in retinal vascular density at 4th follow up compared to before amblyopia therapy.