Foveal Hypoplasia in Patients with Stickler Syndrome

Abstract

Purpose: To determine the microstructure of the fovea in patients with Stickler syndrome using imaging by spectral-domain optical coherence tomography (SD OCT) and swept-source OCT.

Design: Retrospective case series study.

Participants: A total of 39 eyes of 25 patients with genetically confirmed Stickler syndrome were studied.

Methods: All of the patients had mutations in the COL2A1 gene and were diagnosed with Stickler syndrome. Cross-sectional OCT images, OCT angiography (OCTA), and en face OCT images were assessed. The ratio of the foveal inner retinal layer (fIRL) thickness to the parafoveal inner retinal layer (pIRL) thickness, the ratio of the foveal outer retinal layer (fORL) thickness to the parafoveal outer retinal layer (pORL) thickness, and the size of the foveal avascular zone (FAZ) were determined.

Main outcome measures: The degree of foveal hypoplasia and the best-corrected visual acuity in patients with Stickler syndrome.

Results: A persistence of the inner retinal layers in the fovea with an fIRL/pIRL ratio >0.2 was present in 32 of the 39 eyes (82%). Optical coherence tomography angiography showed that the FAZ was smaller, 0 to 0.19 mm², than that of normal eyes, in 25 eyes of 17 patients who underwent OCTA. There was no significant correlation between the visual acuities and the fIRL/pIRL ratios.

Conclusions: A mild foveal hypoplasia with a persistence of the IRL is characteristic of eyes with Stickler syndrome. The visual acuities were not correlated with the fIRL/pIRL ratios.