Abnormal fundus autofluorescence results of patients in long-term treatment with deferoxamine

PURPOSE:To describe and classify patterns of abnormal fundus autofluorescence (FAF) of patients with β-thalassemia receiving long-term treatment with deferoxamine (DFO). DESIGN:Prospective, cross-sectional, case-control study. PARTICIPANTS:A total of 197 consecutive patients with β-thalassemia major or intermedia with at least 10 years of treatment with DFO were recruited in a tertiary referral center in Milan, Italy, and were investigated. Seventy-nine thalassemic patients without a history of chelation therapy were included as a control group. METHODS:All of the patients were investigated using best-corrected visual acuity (BCVA), fundus photography, and FAF imaging by confocal scanning laser ophthalmoscopy (cSLO) and were compared with the control group. MAIN OUTCOME MEASURES:Identification of abnormal FAF patterns in thalassemic patients treated with long-term DFO and their progression and relationship with visual function. RESULTS:Abnormal FAF not related to other diseases was observed in 18 of the 197 patients (9%) and was classified into 4 phenotypic patterns: minimal change, focal, patchy, and speckled. The abnormal increased or decreased FAF was bilateral in all the cases, and only in some cases did it correspond to funduscopically visible alterations. There were no FAF abnormalities in the control group. During the follow-up, progressive FAF changes related to retinal pigment epithelium (RPE) damage occurred in the patchy pattern, associated with decreasing BCVA. Patients with speckled and focal patterns showed limited or no changes in FAF during the follow-up. No changes in FAF were found in patients with a minimal change pattern. No treated patient with a normal baseline examination demonstrated FAF changes. Patients with patterns other than the minimal change showed significant BCVA deterioration (P<0.001). CONCLUSIONS: Various phenotypic patterns of abnormal FAF can be identified with cSLO imaging. Fundus autofluorescence is a helpful, fast, and noninvasive tool for monitoring the status of the macula in patients at risk of DFO toxicity. It may be useful in the decision to discontinue or switch the therapy in cases of particular high risk for disease progression. The progressive alteration of the RPE suggests an important role of pathologic RPE changes in the evolution of visual loss during long-term treatment with DFO