Circulating anti‐retinal antibodies in response to anti‐angiogenic therapy in exudative age‐related macular degeneration

Purpose To determine changes in anti‐retinal antibodies ( ARA s) during anti‐ VEGF therapy in patients with exudative age‐related macular degeneration ( AMD ) and to assess the correlations between ARA s and disease activity. Methods The study comprised 98 patients treated with intravitreal bevacizumab. The ophthalmic examination included best corrected visual acuity ( BCVA ), slit lamp biomicroscopy, fundoscopy, fluorescein angiography ( FA ), and optical coherence tomography ( OCT ). Serum ARA s levels were assessed by indirect immunofluorescence ( IIF ) on normal monkey retina substrate. These studies were repeated at 4 week intervals within 8 months of a follow‐up. The sera of 50 sex‐ and age‐matched healthy subjects were used as controls. Results At baseline examination, 94 (95.5%) of the 98 patients were positive for ARA s. The ARA s titres were significantly higher (p = 0.0000) than in controls. A positive correlation was found between titres of ARA s and the diameter of choroidal neovascularization ( CNV ) as measured by FA (p = 0.0000), and central retinal thickness ( CRT ) assessed by OCT (p = 0.0000). A positive correlation was also found between the diameter of CNV , CRT and the complexity of circulating ARA s. Following treatment all patients demonstrated significant decrease in ARA s levels as well as improvement of BCVA , reduction of subretinal fluid on OCT and decreased leakage on FA . Conclusion Changes in serum ARA s levels occurred in parallel with clinical outcomes of anti‐ VEGF therapy. Treatment reduced serum levels of ARA s , with the greatest reduction occurring during the ‘loading’ phase. This study demonstrated that ARA s may act as a serum biomarker of the efficacy of anti‐ VEGF therapy.