Panretinal Photocoagulation Indications

Primary Indications

The American Diabetes Association recommends panretinal photocoagulation (PRP) to reduce the risk of vision loss in patients with high-risk proliferative diabetic retinopathy (PDR) and, in select cases, severe nonproliferative diabetic retinopathy (NPDR) 1, 2
PRP is most strongly indicated when any three of the following four features are present: neovascularization at or near the optic disc, neovascularization elsewhere, vitreous or preretinal hemorrhage, or any neovascularization at any location when combined with the above features 3
The Diabetic Retinopathy Study (DRS) demonstrated that PRP reduced severe vision loss from 15.9% in untreated eyes to 6.4% in treated eyes, with the greatest benefit in those with more advanced baseline disease including disc neovascularization or vitreous hemorrhage 1, 2

PRP may be considered in select cases of severe NPDR, particularly in very severe NPDR defined by the 4-2-1 rule: severe intraretinal hemorrhages in all 4 quadrants, venous beading in 2+ quadrants, or prominent intraretinal microvascular abnormalities (IRMA) in 1+ quadrant 3
Type 2 diabetes patients with severe NPDR benefit more from early PRP than type 1 patients, with a 50% reduction in severe vision loss or vitrectomy (2.5% vs 5%) 4, 5

The American Academy of Ophthalmology suggests that for Type 1 Diabetes, the timing of PRP depends on patient compliance with follow-up, status of the fellow eye, and presence of pregnancy or impending cataract surgery 4, 5
For Type 2 Diabetes, early PRP before high-risk PDR develops is particularly appropriate, as these patients show greater benefit from early intervention 4, 5
Anti-VEGF therapy (ranibizumab, aflibercept, bevacizumab) is a reasonable alternative to PRP for proliferative diabetic retinopathy, with the DRCR.net Protocol S demonstrating that ranibizumab was noninferior to PRP at 2 years 1, 2, 6

When center-involved diabetic macular edema (CI-DME) is present with PDR requiring PRP, combined anti-VEGF therapy and PRP at the first treatment session should be considered 4
PRP can exacerbate macular edema and should not be performed in isolation when significant DME threatens vision 4

Do not delay PRP when high-risk PDR is present, even if macular edema is present—treat both concurrently 4
Do not perform partial or limited PRP—full PRP with 1200-1600 spots is the proven treatment approach 3, 4
Do not choose anti-VEGF monotherapy for patients with poor compliance or unreliable follow-up—these patients require the durability of PRP 3, 4
Do not assume pregnancy is a contraindication to PRP—pregnancy accelerates retinopathy progression and PRP can minimize vision loss risk 1, 7