Abstract
Purpose :
Trisomy 21 is the commonest trisomy reported 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 Down’s Syndrome.
Methods :
Twenty-one consecutive patients (13 males and 8 females) with a clinical and genetically confirmed diagnosis of Trisomy 21 were enrolled as cases in the study. The 21 controls (15 males and 6 females) were derived from the pediatric ophthalmology clinic. Both cases and controls were of Asian Indian ethnicity. Those recruited underwent SD-OCT imaging on a hand-held device (Envisu, Bioptigen, USA). Scan lengths of 8 mm x 8 mm, 150 frames/eye/second were captured and the best frame analyzed. The morphology and thickness of the central fovea (CFT), inner retinal persistence (IRP) at the fovea, outer plexiform layer (OPL), external limiting membrane (ELM) and outer segment-retinal pigment epithelium (OS-RPE) were measured and compared between the groups.
Results :
The mean age of the cases was 23 months (range 3 – 78 months) and all had a normal fundus on ophthalmoscopy. The mean age of the cases was 28 months (range 3 - 80 months). SD-OCT imaging showed CFT was comparable between the two groups (206±38 in Down versus 221±65 in controls, p=0.213). Inner retinal fusion was complete in the foveal center in only 6 eyes (14.6%) of cases compared to 35 eyes (85.4%) of controls (p<0.001). The OPL was uniform and normal in contour in 22 eyes of cases (53.7) compared to all eyes (100%) of the controls. Only 23 eyes of DS cases (56.1 %) had a normal ELM compared to 37 eyes of controls (90.2%, p<0.001). The OS-RPE layer was normal in 2 (4.9%) cases compared to 18 (43.9%) controls (p<0.001).
Conclusions :
SD-OCT imaging offers a unique opportunity of obtaining in-vivo histology like images of sub-clinical entities. Down syndrome babies appear to have persistence of the inner retina at the fovea as well as thinner retinal layers compared to their normal counterparts and may contribute to the visual development.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.