Evaluation of macular microvasculature by optical coherence tomography angiography in children with amblyopia

Author: Meher Henchiri (Tunisia)

Co-authors: Rahma Saidane, Racem Choura, Asma Khallouli, El Ouafi Bouazzaoui, Afef Maalej, Riadh Rannen

Purpose

To assess retinal microvascular changes in children with amblyopia using Optical Coherence Tomography Angiography (OCTA).

Setting/Venue

Department of Ophthalmology of the Military Hospital of Tunis, Tunisia.

Methods

We conducted an observational study including 24 amblyopic eyes of 20 children (age <18 years) and 40 control eyes of 20 age-matched healthy subjects. All included individuals underwent a complete ophthalmic examination including visual acuity, refraction, ocular motility tests, anterior and posterior segment examination as well as OCT-A. The study enrollment was led between September 2020 and February 2021. Amblyopia was defined as best-corrected visual acuity (BCVA) between 20/40 and 20/200 in one or both eyes without organic cause for the decreased vision. OCTA was performed using Optovue RTVue XR Avanti, AngioVue. 6 mm x 6 mm macular scans with measurement of the foveal avascular zone (FAZ) and vessel densities (VD) in both superficial (SCP) and deep (DCP) capillary plexus were analyzed.

Results

The mean age was 8.6 years ± 4.4 in the study group and 10.4 years ± 3.6 in healthy control group. The mean logMAR BCVA was 0.51 (0.33-0.82) in the amblyopia group and was −0.03 (−0.12 -0.00) in the control group (p < 0.001). No significant refractive difference in spherical equivalent was found between the 2 groups (p=0.08). The macular vessel densities were significantly lower in the amblyopic group than in the control in the SCP (48.2% ±4.1 and 52.1%± 2.8; p=0.02) and the DCP (53.3% ±4.8 and 60.1% ±3.3; p= 0.002). Compared to the control group, the FAZ was significantly larger in amblyopic eyes than in normal eyes (0.47 ± 0.02 mm2 and 0.38 ± 0.01 mm2 respectively; p=0.01).

Conlusions

Amblyopia is the most common cause of visual impairment in childhood. We found that OCTA reveals microvascular alterations in eyes with amblyopia. However, further studies are warranted to confirm the mechanism underlying these findings.

Financial Disclosure

The authors declare no conflict of interest.