Advantages:

Surgically induced cystoid macular edema (SICME) is a complication that can occur after various types of intra-ocular surgeries. SICME could be seen following glaucoma surgery, iridotomies, penetrating keratoplasty, scleral buckling, anterior vitrectomy and pars plana vitrectomy (PPV). The incidence of SICME is usually higher in more complicated procedure (combined procedures). There are several articles documenting that SICME may influence the recovery of vision after anterior segment surgery. However, there are only a few papers describing the incidence of SICME following the PPV. In our patients the incidence of SICME was 12.8% after PPV and of 16.4% after PPV (done due to ERM) combined with cataract surgery (study under review). The most common anti-inflammatory topical medication can usually give complete resolution of SICME secondary to anterior segment surgery. However, SICME secondary to pars plana vitrectomy often becomes chronic and refractory. The purpose of this study was to evaluate the efficacy of the intravitreal implant of Dexamethasone 0.7 mg (Ozurdex, Allergan, Irvine, Calif, USA) (IVO) for the treatment of refractory SICME after PPV performed due to ERM.

Methods:

Six eyes of 5 patients, affected by refractory SICME, had undergone IVO. Best corrected visual acuity (BCVA), intraocular pressure and fundus examination were performed at baseline and every month after IVO. Central foveal thickness (CFT) and macular morphology were studied with optical coherence tomography (OCT) every month during the six-month follow-up.

Effectiveness / Safety:

The mean duration of SICME was 21,7±18,86 months. Mean pre-operative ETDRS logMAR BCVA was 0,62±0,35 (0,70-1). Mean pre-operative CFT was 655±173 microns (445-800 microns). In control group, mean post-operative logMAR BCVA was 0,4±0,37, (1-0) and mean post-operative CFT was 279±78 microns (180-350 microns). There was a recurrence of SICME more than six months after IVO.

The visual recovery after treatment with IVO was related to the duration of edema, while CFT reduction did not seem to depend on the duration of the disease. Further studies are needed to understand factors playing role in the formation and persistence of SICME. There are unknown reasons why SICME may occur, reoccur or respond differently to various treatments. However, the IVO proved to be an effective and safe treatment. It reduces the SICME and limits the damage of photoreceptors that occurs if fluid persists in the foveal region.