Flourescein Fundus Angiography Features of Macular Ischemia in Radiation Retinopathy

Abstract

Purpose: This study aims to describe and investigate the changes seen on flourescein fundus angiography (FA) in the macula of patients diagnosed with radiation retinopathy (RR).

Methods: Design: Retrospective, case control study. Participants: Seven patients with RR secondary to radiation therapy. Methods: The on-line patient database at Moorfields Eye Hospital, London was searched to find patients diagnosed with RR that had undergone FA. Digital images derived from the FA were analysed using custom software to quantify areas of macular ischemia. Main Outcome Measures: FA derived measurements for areas of macular ischemia and rate of change in these areas.

Results: Seventeen patients were found to have a diagnosis of RR, of which seven had FA of sufficient quality to allow analyses. All seven patients developed RR secondary to external radiation therapy for non-ocular malignancy. The mean age of the patients was 61.2 years (SD 21.5) with a male to female ratio of 4:3. Of the seven patients investigated, nine eyes showed evidence of RR, of which five eyes had repeat FA which we were able to compare. In the seven eyes studied, the mean area of macular ischemia was 0.507mm² ± 0.461. Of the five eyes with repeat FA, all eyes demonstrated an increase in the area of macular ischemia between imaging with a mean time interval between angiographies of 2.4 years ± 1.173. Four of the five eyes suffered loss of visual acuity between imaging studies. The mean area of macular ischemia in the repeat FA was 0.639mm² ± 0.537 and the mean change in macular ischemia was 0.350mm² ± 0.406, with a mean rate of change in macular ischemia being 0.177mm²/year ± 0.194.

Conclusions: This study shows that macular ischemia is present in patients with RR and that changes in macular ischemia may correlate with loss in visual acuity. Monitoring of changes in areas of macular ischemia on FA may provide a tool for monitoring disease progression and therefore provide an indicator to which patients are more likely to benefit from early treatment to prevent loss of visual acuity and complications associated with RR.

Keywords: 671 radiation therapy • 585 macula/fovea • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)