TREATMENT & DIABETES

Both intravitreal bevacizumab and triamcinolone appear to improve outcomes in patients with diabetic macular oedema (DME) undergoing cataract surgery, with little difference seen between the two agents, reported Salmaan Al-Qureshi MBBS, FRANZCO at the annual meeting of the American Society of Retina Specialists in San Diego, California.

Dr Al-Qureshi provided an update on the latest results from the prospective randomised trial of intravitreal bevacizumab versus triamcinolone for patients with DME at the time of cataract surgery (DiMECAT study).

“We know cataract and diabetes co-exist and both are common causes of vision loss. The outcome of cataract surgery in diabetics is unpredictable, with poorest outcomes seen in patients who have DME at the time of cataract surgery. Yet, despite advances in surgery there is little evidence regarding use of anti-VEGF agents or triamcinolone in this setting,” he said.

The lack of any prospective studies looking at this question prompted Dr Al-Qureshi and colleagues at the University of Melbourne, Australia to design a single masked prospective randomised trial. All patients participating in the trial had to have visually significant cataracts, with co-existing DME not amenable to laser treatment.

The patients were randomised to receive either intravitreal triamcinolone or bevacizumab following cataract surgery. The primary endpoint was best-corrected visual acuity at one, six and 12 months. Researchers also looked at macular thickness, the number of re-treatments and adverse effects.

Dr Al-Qureshi presented interim results for 46 patients available for follow-up at six months. At three months, both treatment groups showed significant improvement in visual acuity, with triamcinolone recipients gaining an average of 21 letters and bevacizumab patients gaining 14 letters.

Patients receiving triamcinolone, but not those receiving bevacizumab, also showed a slight decrease in central macular thickness. This pattern continued at six months. However, these differences did not reach statistical significance.

Re-treatments were done monthly if there was an increase in central macular thickness of 50 microns or more, or decrease of five letters or more. At six months the re-treatment rate was 0.19 in the triamcinolone group, compared with 1.93 in the bavacizumab group.

Adverse events were rare, with one case of an intraocular pressure (IOP) spike following treatment with triamcinolone. This was controlled effectively with topical agents.

“The discussion really is that there are few studies of DME and cataract surgery. Intravitreal triamcinolone acetonide has been advocated by some as best treatment for DME. Cataract surgery appears to be an inflammatory insult to the diabetic eye. While anti-VEGF agents work only via one modality, triamcinolone will work in both an anti-inflammatory mode and with anti-VEGF action. The early clinical experience supports this premise,” said DrAl-Qureshi.

Meanwhile, the ESCRS has announced the launch of the PREvention of Macular EDema after cataract surgery (PREMED) study, which has now enrolled its first patients.

Salmaan Al-Qureshi: shq@unimelb.edu.au