CME MANAGEMENT

The ESCS-funded PREvention of Macular EDema after cataract surgery (PREMED) study should help to provide evidence-based recommendations for clinical guidelines to prevent the occurrence of cystoid macular oedema (CME) after cataract surgery in patients with and without diabetes mellitus (DM). The PREMED study is an initiative of the University Eye Clinic Maastricht UMC, the Netherlands, under the supervision of Prof Rudy Nuijts MD, PhD.

“To our knowledge, only few well-designed randomised studies have compared nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids as a solitary antiinflammatory treatment in the prevention of CME after cataract surgery. The incidence of CME varies in the scientific literature between four per cent and 20 per cent in healthy subjects after cataract surgery. However, the majority of these patients have no reduction of visual acuity. Therefore, the incidence of clinically significant macular oedema (CSME) is estimated between zero and 5.8 per cent,” Laura H P Wielders MD told delegates at the XXXI Congress of the ESCRS in Amsterdam. The enhanced risk of CME after cataract surgery in diabetic patients has also been factored into the study design, said Dr Wielders.

“About 16 per cent of all patients undergoing cataract surgery are diabetics and 50 per cent of postoperative CME patients also have DM. It is known that patients with DM have a higher risk of developing CME after cataract surgery: in up to 56 per cent in previous studies,” she said. Current preventive measures to reduce the potential risk of CME after cataract surgery vary widely from centre to centre, noted Dr Wielders.

“There is a lot of variety in clinical practice. Of 12 centres currently participating in the PREMED study, most use an NSAID and a corticosteroid to prevent inflammation and CME after cataract surgery. However, some centres use no NSAIDs and others do not use corticosteroids at all. It should also be borne in mind that none of these centres has a separate protocol for patients with DM,” she said. When enrolment is complete, the PREMED study will include 1,050 non-diabetic and 300 diabetic patients.

All patients undergoing routine phacoemulsification will be included in the study, except those meeting exclusion criteria such as previous ocular surgery, history of glaucoma or increased IOP, retinal vein occlusion, uveitis or macular pathology that might influence visual acuity. The final results of the study are expected in the 2015-2016 time frame.

Further treatment

Only one eye per patient will be included in the study. The choice of antibiotics used will be left to the participating centre, although the chief investigators recommend intracameral cefuroxime as per the ESCRS Endophthalmitis Study.

Further treatment will differ for diabetic and non-diabetic patients, noted Dr Wielders. Non-diabetic patients will be randomised to receive topical Bromfenac, topical Dexamethasone or both of these drugs, while diabetic patients, with a higher risk of CME, will receive both. Diabetic patients will be randomised to receive no additional drugs, a subconjunctival injection of Triamcinolone Acetonide, an intravitreal injection of Bevacizumab or both.

The primary endpoint of the study is the change in central subfield mean macular thickness (CSMT) as compared to baseline at six weeks postoperatively. The secondary endpoint is the occurrence of CSME within 12 weeks postoperatively. In case of CSME, treatment will be initiated and its effect will be part of the evaluation at 12 weeks. Medical data of all patients who develop CSME during the study will be checked at the end of the study and at least six months after surgery.