Swept-source optical coherence tomography study of choroidal morphology in Stargardt disease

BACKGROUND: Stargardt disease, a juvenile retinal dystrophy, may show secondary changes in the choroid which may have importance while considering future treatments such as stem cell transplant. OBJECTIVE: To evaluate the choroidal and retinal morphology in patients with Stargardt disease and compare with age-matched normals. SETTING AND DESIGN: This was a case–control study at a tertiary level eye care institute. METHODS: Twenty-six patients (52 eyes) clinically diagnosed with Stargardt disease underwent detailed evaluation with swept-source optical coherence tomography. Retinal and choroidal layers were analyzed and compared with 52 eyes of controls. RESULTS: The median age of patients with Stargardt disease was 23 years. The mean best-corrected visual acuity was 0.82 logMAR (20/125 Snellen). Mean diameter of the lesion was 2810.92 ± 1311.15 μ. The lesion size increased with increasing extent of flecks and was significantly correlated with visual acuity (r = 0.622, P < 0.001). The retinal and choroidal thicknesses (CTs) were significantly reduced in Stargardt group. The mean subfoveal CT was 290.59 ± 60.43 μ(range: 184–395) in Stargardt and 331.31 ± 68.90 μ (range: 199–464) in normal group, P = 0.043. CT in Early Treatment Diabetic Retinopathy Study grid pattern showed significant thinning in Stargardt group. The small choroidal vessel (SCV) layer was more affected than the large choroidal vessel (LCV) layer. There was thinning of SCV and thickening of LCV inside the macular lesion. The CT was not correlated to lesion size, extent of flecks, or visual acuity. CONCLUSIONS: Stargardt disease shows generalized thinning of the choroid affecting mainly the SCVs. In the macular lesion, there is atrophy of SCV with compensatory dilation of LCV. The visual acuity did not correlate with CT but showed worsening with increasing lesion size and wider extent of flecks.