Optical Coherence Tomography Angiography in Stargardt disease

Abstract

Purpose : To describe vascular changes in different stages of Stargardt`s disease (STGD) using double swept source optical coherence tomography angiography (dSS-OCTA).

Methods : Cross-sectional, one center case control study. All 23 participating patients (13/10 females/males, 45 eyes) with ABCA4 mutation were clinically graded according to the Fishmann STGD classification and examined via dSS-OCTA (PlexElite, Zeiss). 23 healthy, age-matched participants (23 eyes) served as controls. Two independent investigators graded the foveal avascular zone in the superficial and deep capillary plexus (SCP and DCP). The areas of reduced flow and total vascular atrophy in the outer retina to choriocapillaris (ORCC) and the choriocapillaris (CC) slap, were analyzed according to the slaps predefined by the manufacturer. Mann-Whitney U test and ANOVA Bonferroni post hoc test were used for statistical analysis.

Results : The mean age at first diagnosis of STGD was 24.0 years (range 9-50) and 37.9 years (range 18-74) at time of examination. Eleven patients were assigned to the Fishman STGD classification S1, three to S2, eight to S3 and one to S4. The foveal avascular zone in the SCP and DCP were increased (p<0.0001) in all STGD stages compared to controls. In contrast to controls, STGD patients of all stages revealed enlarged foveal avascular zone in the SCP compared to the DCP slap (p=0.02). Patients of all stages revealed decreased flow in the ORCC and CC compared to the controls. The affected areas were more pronounced in the ORCC compared to the CC (p=0.03) and smaller in STGD S1 compared to other STGD stages (p<0.0001). The time since initial diagnosis of the disease correlated significantly with the extent of the enlarged foveal avascular zone in the SCP/DCP slap and with the area of reduced flow in the ORCC/CC slap (p<0.01).

Conclusions : STGD patients of all stages reveal vascular alterations in the retina and choroid. The avascular zone in the SCP/DCP and the reduced flow in the ORCC/CC slap increases with duration and stage of STGD indicating a progressive vascular decay. Interestingly, the vessels depicted in the ORCC exhibit more alterations compared to the CC indicating a significant vascular damage in the retina in STGD.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.