Feeder Vessel Navigated Laser Treatment In Non-responder Exudative Age-related Macular Degeneration

Abstract

Purpose: : To evaluate the feasibility of feeder vessel (FV) treatment in non-responder exudative age-related macular degeneration (AMD) patients, using a navigated laser system.

Methods: : Consecutive patients affected by exudative AMD that underwent 3 monthly intravitreal injections of ranibizumab were evaluated with visual acuity testing (VA), optical coherence tomography (OCT) and dynamic indocyanine green angiography (ICGA). Patients were defined as non-responders if they showed a decrease in VA and/or stable/worsened central retinal thickness (CRT) by OCT. Dynamic ICGA was evaluated to detect the choroidal FV. Non-responder patients with evidence of FV were enrolled in the study and underwent laser photocoagulation of the FV. A navigated laser system (Navilas® laser system, OD-OS, Teltow, Germany) was used to perform the treatment. Early frames of ICGA showing the location of the FV were imported into the laser instrument and used to plan the treatment. Laser was delivered on the FV with spots of 100 ms and 100 µm. Laser was repeated with increasing power values, starting from low intensity, until one of the following was obtained: 1) reduction/disappearance of the FV in color fundus photographs; 2) grayishing of tissue in the treated area. After treatment, dynamic ICGA was repeated to assess the closure of FV. Patients were re-evaluated 1 and 3 months later with VA testing, OCT and ICGA.

Results: : Five eyes from 5 patients were enrolled in the study. The navigated laser allowed a precise treatment of the area corresponding to the FV. Four patients required only one laser session to obtain closure of the FV. One patient required 2 consecutive laser sessions. At one-month follow-up the FV was closed in 4 out of 5 patients. Visual acuity was stable (mean difference from baseline +2 ETDRS letters). OCT showed a reduction from 353 to 300 µm in the mean CRT. After three months FV was still closed in 4 out of 5 patients. Visual acuity was stable (mean difference from baseline +1.6 ETDRS letters). OCT showed a mean CRT of 325 µm.

Conclusions: : In patients affected by exudative AMD the treatment of FV may be alternative to observation. The use of a navigated laser system with integration of ICGA images makes the treatment feasible and accurate.

Keywords: age-related macular degeneration • choroid: neovascularization • laser