Spectral Domain Optical Coherence Tomography in Detecting Sub-Clinical Retinal Findings in Asian Indian Children with Down Syndrome.

Purpose: Trisomy 21, also known as Down syndrome (DS), is the most common trisomy worldwide. Although ocular associations have been reported, retinal anatomy and pathology remain uninvestigated. We evaluate the role of spectral domain optical coherence tomography (SD-OCT) in analyzing foveal morphology of children with DS. Methods: Nineteen consecutive DS children and eight controls were enrolled under a cross-sectional study in an institutional practice. All subjects underwent SD-OCT imaging on a hand-held device. The morphology and thickness of central fovea, inner retinal layers, outer retina, and photoreceptor layers were measured and compared with age-group sub-analysis. Results: Mean age of the cases was 24 months (3-78 months). All cases and controls had a normal fundus on ophthalmoscopy and foveal thickness was comparable (p = 0.718). Inner retinal fusion was complete in the foveal center in only three eyes (15.8%) of cases compared to all eyes (100%) of controls (p < 0.001). The outer plexiform layer was normal in 10 eyes of cases (52.6%) compared to all eyes (100%) of the controls. Only 10 eyes of DS (52.6%) had a normal external limiting membrane, compared to all eyes of controls (100%, p = 0.01). The interdigitation zone (outer segment) was normal in one (5.3%) case compared to eight (67%) controls (p = 0.001). On subgroup analysis, in older cohorts, cases had a greater proportion of abnormal layers compared to controls. Visual acuity was found to be lower in cases when compared to controls, although not significant (p = 0.19). Conclusion: DS babies have abnormal foveal morphology and persistence of inner retinal layers. This may assist our understanding of their visual development.