Abstract: Objective To investigate the effects of pan-retinal photocoagulation (PRP) in patients with preproliferative （PPDR）and proliferative（PDR）diabetic retinopathy (DR) that underwent cataract surgery. Design Retrospective case series. Participants Sixty five patients (95 eyes) diagnosed with FFA as having proliferative and preproliferative DR with moderate or severe cataract. Methods In all patients we were able to see the fundus, patients with PPDR and PDR were divided into two groups according to patient′s condition after obtaining informed consent. Group A was treated with IOL implantation following peripheral laser for 2 times, then photocoagulation was carried out for 2 times during 1 month. Group B was treated with IOL implantation and then PRP treatment were given for 3 times (each time interval for one week) after 1 month. The results of FFA were used to grade DR. Obvious effects: The original neovascularization was completely atrophied and non-perfusion areas disappeared. Effectiveness: neovascularization and non-perfusion areas mostly disappeared. Ineffectiveness: no change in neovascularization, presence of vitreous hemorrhage or neovascular glaucoma. Main Outcome Measures Best corrected visual acuity, new blood vessels and areas of no perfusion evaluated with FFA, macular center thickness evaluated by OCT. Results The proportion of patients with improved visual acuity and stable visual acuity in PPDR patients before and after laser surgery was 90.5% (19/21) in group A and 86.4% (19/22) in group B, with no significant difference between the two groups (P=0.12). In PDR patients, the proportion of patients with improved visual acuity and stable visual acuity was 76.9% (20/26) in group A and 65.4% (17/26) in group B, with a statistically significant difference (P=0.02). In PPDR patients, as shown by FFA, non-perfusion areas largely disappeared in Group A (85.7% (18/21)), and in Group B (81.8% (18/22)), without significant difference between the two groups (P=0.1). In PDR patients, non-perfusion areas largely disappeared in group A (61.5% (16/26)) and in group B (42.3% (11/26)), with a  significant difference between the two groups (P=0.03). There was no significant change in the thickness of the macular center in the two treatment groups of PPDR patients (Group A: 213±11.8 μm; Group B: 189±10.4 μm, P=0.1). The macular foveal thickness of PDR treatment Group A was significantly lower in treatment Group B (group A: 286±16.7 μm; group B: 425±20.7 μm; P=0.01). Conclusion Pan-retinal photocoagulation treatment in PDR patients with  cataract is more effective for PDR when given before IOL implantation than after. (Ophthalmol CHN, 2013, 22:90-93)

Key words: diabetic retinopathy (DR), cataract/surgery, pan-retinal photocoagulation (PRP)