Abstract
Purpose: :
Fundus autofluorescence (FAF) indicates metabolic changes of the retinal pigment epithelium (RPE). The activity of overlying photoreceptors depends on the functional integrity of the RPE. Aim of this study was based on this background to evaluate AF as a possible prognostic indicator for therapeutic outcome of intravitreal treatment of exsudative age related macular degeneration (AMD) with ranibizumab.
Methods: :
We evaluated retrospectively 131 AF images (Heidelberg Retina Angiograph, 488 nm) of 131 eyes (131 patients, 87 women, 44 men, mean age 75 years) affected by exsudative AMD before initiation of ranibizumab loading therapy and on follow up. We analysed FAF of the macula in circles of 500, 1000, and 2000 µm diameter around the foveola. Results were graded as normal, decreased or increased autofluorescence. On inhomogeneous images the major area of autofluescence change was considered. The therapeutic outcome of ranibizumab loading therapy was determined by change of visual acuity (VA) and central retinal thickness as measured by optical coherence tomography (OCT).
Results: :
In the analysis of FAF in the central 500 µm area 42,0 % (55/131) of patients showed normal, 46,6 % (61/131) increased and 11,5 % (15/131) decreased AF. In the 500 µm area group eyes with normal FAF had significant better outcome of VA compared to eyes with increased FAF (p= 0,023) and decreased FAF (p= 0,037). In the 1000 and 2000 µm area groups no statistic significant differences were found. There was no significant relation between FAF patterns and change of the central retinal thickness measured by OCT.
Conclusions: :
Our results show that VA in patients without metabolic changes of RPE in the central 500 µm area improves significantly after ranibizumab loading therapy compared to patients with alterations in FAF. As FAF alterations presumably represent different stages of AMD progression, the metabolic status of RPE is a significant indicator for the therapeutic outcome of ranibizumab loading therapy.
Keywords: age-related macular degeneration • macula/fovea • vitreous