Purpose:
To evaluate fundus autofluorescence findings at different stages of macular telangiectasia type 2 (MacTel 2) and to document their change over time.
Methods:
Retrospective analysis of patients diagnosed with MacTel 2 who underwent fundus autofluorescence (FAF) imaging as part of their clinical work-up. FAF imaging was performed using the Heidelberg Retina angiograph II, Spectralis HRA+OCT (Heidelberg Engineering Inc., Heidelberg, Germany) or a Topcon fundus camera (Topcon Optical, Tokyo, Japan) fitted with filters according to Spaide’s specifications (excitation at 580nm, barrier filters at 695nm). Clinical information including age, sex and best-corrected visual acuity, fluorescein angiographic findings, and optical coherence tomography (OCT) observations were recorded. Prior treatments including intravitreal anti-VEGF therapy were reviewed.
Results:
Fifty-two eyes of 26 patients [8 male; 18 female; mean age: 62.7 years (39 - 82 years)] were included in the study. Thirteen patients had additional FAF examinations with a mean follow-up of 25.4 months. Nine patients had treatment with intravitreal anti-VEGF therapy. Two patients had prior intravitreal steroid injections. At baseline, 16 eyes were classified as stage 1, 12 eyes as stage 2, 12 eyes as stage 3 and 10 as stage 4 (Yannuzzi classification). Two eyes did not show any angiographic evidence of telangiectasia. Either increased areas of hyper- or iso-FAF were seen in stages 1 and 2 eyes. Eyes with more advanced stages showed heterogenous findings including hypofluorescence related to pigment and hyper-FAF related to subretinal neovascularization. Changes in FAF patterns over time were seen in all but 1 patient with stages 3-4 and in 3 eyes with stages 1 and 2.
Conclusions:
Changes in FAF correlate with disease severity in eyes with MacTel 2. Advanced stages show more extensive FAF alterations, which seem more likely to progress over time. Larger prospective studies, such as the MacTel study, are needed to verify these observations and to determine if FAF changes are solely related to advanced disease or possibly accelerated by intravitreal anti-VEGF therapy.
Keywords: retina • imaging/image analysis: clinical • macular pigment