Randomised trial of wide-field guided PRP for diabetic macular oedema treated with ranibizumab.

BACKGROUND: Diabetic macular oedema (DMO) is effectively treated with ranibizumab but multiple injections are required. Where there is also peripheral ischaemia, it has been promoted that targeted panretinal photocoagulation (PRP) may reduce the number of injections. METHOD: Patients with optical coherence tomography confirmed DMO and Ultra-widefield Fundus Fluorescein Angiography confirmed peripheral retinal ischaemia were randomised to PRP plus ranibizumab or ranibizumab monotherapy. After three injections, repeat injections were given until the visual acuity was stable and the macula was dry. Re-treatment was given if there was a drop of visual acuity and/or a recurrence of intra-retinal fluid. The primary outcome was the number of repeat injections required after the first 6 months up until 1 year. RESULTS: There were 49 patients, 25 in the ranibizumab only group and 24 in the ranibizumab + PRP group recruited at seven UK sites. The average number of injections in the ranibizumab-only arm was 6.84 over 1 year and 2.52 between months 6 and 12. The average number of injections in the combined arm was 6.67, with the number of injections in the second 6 months 1.92. For the primary outcome, comparing the number of 6- to 12-month injections, the result was not statistically significant (p = 0.33). CONCLUSION: The addition of targeted PRP to areas of non-perfusion in a patient with DMO does not reduce the number of injections required in the first year. It seems most likely that local VEGF at the macula is the main cause of DMO.

Pharmacokinetic evaluation of pegaptanib octasodium for the treatment of diabetic edema.

INTRODUCTION: Diabetic macular edema (DME) is a leading cause of visual impairment in patients with diabetic retinopathy. Pegaptanib octasodium (Macugen) was the first anti-VEGF agent approved for the treatment of neovascular age-related macular degeneration. It is a selective anti-VEGF agent, which only blocks VEGF. It has been shown to be safe and effective in treatment of DME in randomized controlled trials and it may be a safer first-line treatment in patients with diabetes with a predisposition to cardiovascular risk factors. AREAS COVERED: This review covers the pharmacokinetics of pegaptanib octasodium. The authors also evaluate pegaptanib octasodium's clinical efficacy, safety and tolerability in DME. EXPERT OPINION: DME is the most common cause of visual loss in patients with diabetes. Pegaptanib has been found to be more effective than laser therapy alone for center-involving DME, its efficacy might be slightly worse than other pan-VEGF blockers, but the number of patients that have significant improvement of vision after treatment are similar to those treated with pan-VEGF blockers. As a selective VEGF blocker, it may have a better ocular and systemic safety profile than pan-VEGF blocking agents. It is reasonable to consider pegaptanib as the first-line treatment for center-involving DME with pan-VEGF blockers reserved for non-responders.