Evolution of the laser treatment of diabetic retinopathy (DR): from laser surgery to laser therapy

Purpose To review benefits and collateral effects of conventional photocoagulation, the standard of care for DR, in comparison with newer laser techniques reported to provide comparable benefits with reduced treatment’s hardship and side effects. Methods Literature review and physical/technical considerations. Results Conventional photocoagulation lowers the risk of severe visual loss, but is associated with long, painful, multiple treatments and with iatrogenic anatomical and functional damage. Light panretinal photocoagulation (PRP) has shown efficacy similar to that of conventional PRP with fewer sessions and complications. A patterned scanning laser (PASCAL) allows PRP with reduced surgeon’s time, in 1 or 2 sessions, but still with discomfort and anatomical‐functional damages due to the visible "burn" endpoint. Conversely, subthreshold diode‐laser micropulse (SDM) PRP is a new laser therapy that comparably reduces the incidence of vitreous hemorrhage and vitrectomy with a gentle well tolerated treatment that does not cause iatrogenic vision deterioration or laser‐lesions detectable at any time postoperatively. Conclusion Retinal destruction has never been demonstrated to be a prerequisite for the therapeutic benefits. Whatever the elusive mechanisms of action of laser photocoagulation are, long term benefits can be provided either with high intensity/low density laser surgery or with low intensity/high density laser therapy. Non‐laser treatments for DR are being tested, often with good, rapid, but also only transient effects. The combination of pharmacotherapy's short term beneficial effects with the long term benefits of a less damaging laser therapy appears as a new treatment paradigm that should undergo rigorous investigation.Commercial interest