In the era of antivascular endothelial growth factor (anti-VEGF) injections, one of the most frequent questions I get asked is whether there is any role for laser in the treatment of diabetic eye disease. The short answer is simply “yes.” Laser photocoagulation is noninvasive, generally well-tolerated, and has long-lasting effects that may reduce overall treatment burden compared with anti-VEGF regimens. I’m more likely to use laser as first-line therapy in eyes with proliferative diabetic retinopathy than in eyes with macular edema, but it can be a useful treatment alternative for each of these conditions.
The role of laser as treatment for diabetic macular edema has diminished considerably since 2010, when results from the first phase 3 trial of anti-VEGF therapy demonstrated that, on average, vision gains in eyes receiving anti-VEGF were threefold higher than in eyes receiving laser. Nonetheless, although anti-VEGF therapy is highly effective in many eyes with diabetic macular edema, it necessitates frequent, invasive, and often costly procedures for optimal outcomes. In addition, approximately 50% of patients don’t respond completely to anti-VEGF with complete resolution of edema or return of 20/20 vision. I occasionally use laser as adjuvant therapy to treat eyes with persistent edema and visual impairment despite at least 6 months of prior anti-VEGF therapy. I also perform laser as first-line treatment for selected patients who are not good candidates for anti-VEGF because of pregnancy, recent stroke or heart attack, or inability to comply with the injection procedure or monthly follow-up visits. In eyes with good vision and focal leakage from just a few microaneurysms, I’ll occasionally use macular laser to see if I can reduce the thickening and avoid the need for anti-VEGF therapy.
Laser has a larger role as first-line therapy for many patients with proliferative diabetic retinopathy. The question of whether to use laser vs anti-VEGF injections is trickier in these patients. On one hand, 2 large-scale protocols (the Diabetic Retinopathy Clinical Research Network Protocol S and the CLARITY study) have now demonstrated that anti-VEGF therapy is highly effective at regressing retinal neovascularization and that visual outcomes over 1 to 2 years of anti-VEGF treatment are at least noninferior and possibly superior to those obtained with panretinal photocoagulation. Anti-VEGF, unlike laser, is not inherently destructive and thus avoids the damage to the peripheral visual fields that is commonly present in laser-treated eyes. On the other hand, anti-VEGF injections are a costly and invasive therapy that may not have the same durability-of-treatment effect as laser. Whereas laser-treated eyes often remain stable with quiescent proliferative disease for decades, the recurrence of neovascularization can lead to disastrous visual outcomes in patients treated with anti-VEGF injections who are then lost to follow-up because of sickness or other factors. Ill health and hospitalizations are common among the diabetic population, and even more likely in patients with severe microvascular complications such as proliferative diabetic retinopathy. In general, if an eye presents with both diabetic macular edema and proliferative disease, I’ll treat with anti-VEGF injections and defer laser treatment until the macular edema has resolved, then reevaluate my treatment strategy. In eyes with proliferative diabetic retinopathy that don’t have central-involved macular edema, I like to use anti-VEGF therapy when I can since it avoids the destructive effects of laser. However, I have a low threshold for using laser as first-line treatment for patients who can’t tolerate anti-VEGF injections, who have a history of noncompliance with follow-up visits, or who are medically unstable and might have difficulty with future monthly visits.
I’ve been told by many retina colleagues that their lasers are gathering dust in a corner these days. Our lasers aren’t nearly as active now as they were a couple of decades ago, but I still use them regularly. As longer-acting anti-VEGF formulations become available or new therapeutic alternatives are developed, ophthalmic lasers may well become obsolete. But for now, they still offer a useful tool in the therapeutic armamentarium for diabetic eye disease.