Spectral Domain Optical Coherence Tomography Angiography in Children with Amblyopia

Abstract

Purpose : Amblyopic patients have thicker choroid, choroidal capillary atrophy and increased thickness of the outer segment layer. The purpose of this study is to evaluate novel retinal and microvascular parameters using Spectral Domain Optical Coherence Tomography Angiography in patients with amblyopia younger than 18 years old. There are no studies comparing blood flow in the retinal capillary layers in amblyopic children and controls using non-invasive optical coherence tomography angiography (OCT-A).

Methods : OCT-A case-control study of patients with amblyopia. OCT-A parameters included macular vessel density (MVD) and foveal avascular zone (FAZ) area in the superficial retinal capillary plexus (SCP) and the deep retinal capillary plexus (DCP). Parafoveal thickness of the inner retina was also obtained. Initially, we performed a t-test but then, to adjust by age and refractive error, we performed a logistic regression.

Results : 11 amblyopic eyes of 11 patients and 46 age-matched controls were included. Mean age was 10.1 years (range 5-17 years). Mean MVD of the SCP in the 6x6 scan was 49.5% for the amblyopia patients and 51.1% for the controls (p=0.03). MVD of the DCP was 54.43% and 59.06%, respectively (p=0.02). FAZ at the level of the SCP was 0.26 mm² in patients with amblyopia versus 0.27 mm² in controls (p=0.63). At the level of the DCP, FAZ measured 0.35 mm² in the amblyopia cohort versus 0.34 mm² in controls (p=0.70). Parafoveal thickness was 118.9 μm in the amblyopia patients and 122.45 μm in the control group (p=0.28).

Conclusions : OCT-A in amblyopic eyes demonstrates a statistically significant lower macular vessel density in the superficial and deep retinal capillary plexus. These irreversible structural changes may contribute to decreased visual acuity and poor response to amblyopia treatment.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.