Oedema

An audit of the safety and efficacy of a biodegradable dexamethasone intravitreal implant (OZURDEX®) in Irish patients with macular oedema has found it is less successful than the results reported in a published controlled clinical study. However, this complex Irish patient cohort primarily had chronic macular oedema that was resistant to treatment with anti-vascular endothelial growth factor (anti-VEGF) agents and Kenalog.

Ozurdex is used to treat adults with macular oedema following branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) and to treat adults with non-infectious posterior uveitis.

The Irish study aimed to compare real-life data with the results of the Geneva study (Haller, J A, et al, Randomized, Sham-Controlled Trial of Dexamethasone Intravitreal Implant in Patients with Macular Edema Due to Retinal Vein Occlusion. Ophthalmology, 2010. 117 (6)). The published study concluded that these implants reduce the risk of vision loss and improve vision in eyes with macular oedema secondary to BRVO and CRVO.

The Irish data was presented at the 2014 Irish College of Ophthalmology Annual Conference by Kevin Kennelly MB, BCh, BAO, MRCOphth, MRCSI(Oph), FEBO, BMedSc, MSc, PhD, specialist registrar in ophthalmic surgery at the Mater Misericordiae University Hospital, Dublin.

A retrospective chart review was undertaken of all patients who received the dexamethasone intravitreal implant by a single surgeon, David Keegan MB, BCh, BAO, MMeddSc, FRCSI(Oph), FRCOphth, PhD, consultant vitreoretinal surgeon. A range of data was analysed at one, three, six, 12 and 24 months post-implantation.

Some 20 patients (11 female, nine male) were included in the study, with a mean treatment age of 69.5 years. The mean duration of symptoms was 30 months. Some 50 per cent of eyes had preceding pathology in the treated eye. Patients had previously received a mean of 7.2 anti-VEGF injections, 2.2 intravitreal Kenalog injections and 0.2 sub-tenons Kenalog injections. During the study, six patients received multiple Ozurdex implants.

The mean baseline visual acuity was 50±18 EDTRS letters. The proportion of eyes that gained at least 15 letters was 22 per cent at day 30, 19 per cent at day 90 and seven per cent at day 180.

Key findings

Some 60 per cent of patients suffered at least one ocular adverse event; 50 per cent of phakic patients required cataract surgery within two years, at a mean of 12 months post-implantation. Some 30 per cent of patients developed raised intraocular pressure (IOP), which was controlled in all cases with topical IOP-lowering agents, while 20 per cent developed subconjunctival haemorrhage during the implantation.

This real-life audit found inferior beneficial effects and higher rates of ocular adverse events with Ozurdex compared to the results of the Geneva study. However, this is likely due to broader inclusion criteria, particularly the inclusion of patients with previous ocular pathology, longer duration of symptoms before treatment, off-label use and longer follow-up, Dr Kennelly said.

“In this real-life setting and complex patient cohort we found that Ozurdex was equally effective up to three months, but did not have a sustained effect to six months as was seen in the Geneva study. The higher rate of complications was most probably a consequence of longer follow-up in terms of cataract progression and related to multiple implants in terms of raised intraocular pressure. Nevertheless, our data demonstrates that intravitreal dexamethasone implants provide a definite treatment option for those patients with resistant macular oedema where first-line agents such as anti-VEGF injections have proven ineffective,” Dr Kennelly told EuroTimes.

Kevin Kennelly: kpkennelly@gmail.com