Subretinal Fibrosis in Stargardt's Disease with Fundus Flavimaculatus and ABCA4 Gene Mutation

Abstract

Purpose: To report on 4 patients affected by Stargardt's disease (STGD) with fundus flavimaculatus (FFM) and ABCA4 gene mutation associated with subretinal fibrosis.

Methods: Four patients with a diagnosis of STGD were clinically examined. All 4 cases underwent a full ophthalmologic evaluation, including best-corrected visual acuity measured by the Snellen visual chart, biomicroscopic examination, fundus examination, fundus photography, electroretinogram, microperimetry, optical coherence tomography and fundus autofluorescence. All patients were subsequently screened for ABCA4 gene mutations, identified by microarray genotyping and confirmed by conventional DNA sequencing of the relevant exons.

Results: In all 4 patients, ophthalmologic exam showed areas of subretinal fibrosis in different retinal sectors. In only 1 case, these lesions were correlated to an ocular trauma as confirmed by biomicroscopic examination of the anterior segment that showed a nuclear cataract dislocated to the superior site and vitreous opacities along the lens capsule. The other patients reported a lifestyle characterized by competitive sport activities. The performed instrumental diagnostic investigations confirmed the diagnosis of STGD with FFM in all patients. Moreover, in all 4 affected individuals, mutations in the ABCA4 gene were found.

Conclusions: Patients with the diagnosis of STGD associated with FFM can show atypical fundus findings. We report on 4 patients affected by STGD with ABCA4 gene mutation associated with subretinal fibrosis. Our findings suggest that this phenomenon can be accelerated by ocular trauma and also by ocular microtrauma caused by sport activities, highlighting that lifestyle can play a role in the onset of these lesions.

Keywords: ABCA4 gene; Lifestyle; Ocular trauma; Stargardt's disease; Subretinal fibrosis.

Fig. 1

Case 1 – left eye: diffuse area of subretinal fibrosis. b Case 2 – right eye: area of subretinal fibrosis in the superior juxta-papillar region associated with diffuse pigmentation. c Case 3 – left eye: small area of subretinal fibrosis, macula temporally. d Case 4 – left eye: area of subretinal fibrosis in mid-periphery.

Fig. 2

RPE dystrophy associated with a reduction of macular thickness.