Circulating antiretinal antibodies predict the outcome of anti-VEGF therapy in patients with exudative age-related macular degeneration.

PURPOSE

To determine serum antiretinal antibody (ARA) levels in response to treatment with intravitreal bevacizumab of exudative age-related macular degeneration (AMD).

METHODS

The study comprised 22 patients treated with intravitreal bevacizumab (Avastin) 1.25mg. In all patients, serum ARA levels were assessed by indirect immunofluorescence on normal monkey retina substrate. The ophthalmic examination including best corrected visual acuity (BCVA), fundoscopy, fluorescein angiography, optical coherence tomography (OCT) and immunohistochemical investigations. These were repeated at 4-week intervals during a loading phase of antiangiogenic therapy. Sera of 22 sex- and age-matched healthy subjects were used as controls for immunohistochemical studies.

RESULTS

Before bevacizumab therapy, ARAs were detected in the sera of all patients at titres ranging from 1:40 to 1:1280. The titres were significantly higher (p < 0.01) than in controls (1:10-1:40). There was no significant correlation between serum ARA titres and neither the type nor the dimensions of choroidal neovascularization, as well as central retinal thickness. Following treatment, all patients demonstrated significant decrease in ARA levels. This correlated with improvement of BCVA, decreased leakage of fluorescein and reduction of subretinal fluid on OCT.

CONCLUSION

Serum ARA levels demonstrate a dynamic change which occurs in parallel with clinical outcomes of antiangiogenic therapy. They also may act as markers of the therapeutic benefits of vascular endothelial growth factor inhibition.