Retinal Navigated Laser (Navilas®) Compared Versus Conventional Laser In Diabetic Macular Edema

Abstract

Purpose: : To compare clinical outcomes and re-treatment rates for a novel navigated laser (Navilas) versus conventional laser in the treatment of clinically significant macular edema (CSME).

Methods: : Focal laser for diabetic macular edema (DME) in 38 patients was digitally planned on fundus images and performed utilizing retina navigation with the Navilas® system (OD-OS GmbH, Teltow, Germany). Up to one year clinical follow-up of the case series at two sites investigated number of re-treatments and visual acuity. For a control group propensity score matching (nearest neighbour method) was performed based on of the chart review of 113 patients treated by conventional retina laser at the same institutions during the same time period.

Results: : In total, 79% of laser spots were visible on color images, of which 96% were within 100 µm from the planned target. In the unmatched complete group, the number of laser spots performed per patient with Navilas was 105+/-94; significantly (p<0.001) higher than with conventional laser (43+/-36). Before matching, follow-up available for Navilas patients was significantly shorter than for conventional patients (median 6.8 versus 13.5 months, p<0.001). Propensity score matching of Navilas patients with the conventional laser group for age, gender, baseline visual acuity, number of laser spots and follow-up time yielded 22 matched patients from the control group. Visual acuity at baseline was 0.50 +/- 0.37 LogMAR for Navilas and 0.35 +/- 0.38 LogMAR for conventional laser and remained stable (+/- 3 lines) in all patients after 3 and 6 months. The laser retreatment rate using Kaplan-Meier analysis showed separation of the curves after 2 months with less retreatments in Navilas group over the first 8 months. Given limited follow-up time this difference did not reach statistical significance.

Conclusions: : When performing navigated laser treatment (Navilas) for diabetic macular edema, significantly more laser spots were placed compared to conventional laser. This may be due to the ability to pre-plan and efficiently execute the treatment with the Navilas device. While longer follow-up times are required, the tendency for lower retreatment rates with Navilas may be an important factor when considering possible combination laser and anti-VEGF drug therapy.

Keywords: diabetic retinopathy • laser • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)