The effect of multispot laser panretinal photocoagulation on retinal sensitivity and driving eligibility in patients with diabetic retinopathy

IMPORTANCE: Panretinal photocoagulation (PRP) for proliferative diabetic retinopathy (PDR) may lead to peripheral field loss that prevents driving. Anti-vascular endothelial growth factor agents are proposed as treatments for PDR that spare peripheral vision. If multispot lasers cause less visual field loss, continuing to perform PRP may be justified. OBJECTIVE: To assess the effect of bilateral multispot laser PRP on retinal sensitivity and driving visual fields in PDR. DESIGN, SETTING, AND PARTICIPANTS: This prospective nonrandomized interventional cohort analysis performed at a tertiary referral center included 43 laser-naive patients with PDR that required bilateral PRP. Participants were recruited from June 27,2012, to October 14, 2013. At baseline and 6-month follow-up, patients underwent detailed static and kinetic perimetry, microperimetry, optical coherence tomography, wide-field color fundus photography, and fluorescein angiography. Quantitative change in retinal sensitivity was assessed by comparing the mean global retinal sensitivity before and after laser treatment and by comparing the modeled hill of vision by deriving a volumetric measure. Final follow-up was completed on May 21, 2014. INTERVENTIONS: Multispot laser treatment was applied using standard parameters, until neovascularization regressed or complete retinal coverage was achieved. MAIN OUTCOMES AND MEASURES: Participants who passed the Esterman binocular visual field test for driving in the United Kingdom (at least 120° horizontal field with no significant defects within the central 20°) and full-field and macular retinal sensitivity. RESULTS: Of the 43 patients (17 men; 26 women; mean [SD] age, 46.6 [13.3] years), 38 (88%) completed the study. Before treatment, 41 of 43 patients (95%) passed the Esterman visual field test for driving; after completion of laser treatment, 35 of 38 patients (92%) passed. The mean (SD) change in retinal sensitivity on static perimetry was -1.4 (3.7) (95% CI, -2.7 to -0.1) dBODand -2.4 (2.9) (95% CI, -3.4 to-1.4) dB OS. Mean (SD) 4° macular sensitivity decreased by 3.0 (5.2) dB OD and 2.6 (5.4) dB OS. CONCLUSIONS AND RELEVANCE: This prospective study investigating the effects of multispot laser PRP on retinal sensitivity demonstrates a high likelihood of retaining eligibility to drive based on adequate visual field. A mild loss of retinal sensitivity was detected at 6 months after completion of laser treatment. Further change to visual fields may have occurred with longer follow-up. This study provides information that might be used to counsel patients requiring PRP and informs the debate regarding the role of anti-vascular endothelial growth factor therapy in patients with PDR who might otherwise receive laser treatment.