Accuracy of Focal Laser Treatment Based on External Imaging (OCT) Using a Navigated Retinal Laser System - a Case Series.

Background The navigated laser photocoagulation system (NAVILAS®, OD-OS GmBH, Teltow, Germany) is a laser treatment device that provides navigated laser treatment of the retina based on a fundus image. The purpose of this study was to investigate the accuracy of laser treatment based on external optical coherence tomography (OCT) images - a new application of the device. Patients and Methods This retrospective case series evaluated the accuracy of laser spot placement in 7 eyes after using overlaid external OCT images for planning NAVILAS laser treatment. After a mean time of 33 days, a post-treatment OCT was obtained and compared with the pretreatment plan on the previous OCT. Laser spots touching or overlapping the planned 100 µm laser spots were classified as "match" and invisible laser spots as "laser spot not evolved". Results A total of 477 laser spots in 7 eyes were evaluated (mean: 68 spots per eye). Of all planned laser spots, 361 (75.7 %) were visible on post-treatment OCT. 58.7 % of these spots matched the pretreatment plan. Non-matching laser spots showed no uniform pattern of dislocation. Conclusions Planning navigated NAVILAS Laser treatment based on manually imported OCT images seems to be less accurate than planning with NAVILAS integrated imaging. These findings warrant further evaluation, not only regarding the recently installed automated picture importing tool but also concerning its clinical impact, which is possibly outweighed by the advantages of the additional image information.