One year clinical observation of dexamethasone intravitreal implant (Ozurdex) in the treatment of macular edema secondary to retinal vein occlusion

Abstract

Objective To evaluate the efficacy and safety of dexamethasone intravitreal implant (Ozurdex) in the treatment of macular edema (ME) secondary to retinal vein occlusion (RVO). Methods Thirty-nine patients (39 eyes) with ME secondary to RVO were enrolles in this study. Of the patients, 27 were male and 12 were female. The mean age was (41.9±16.3) years. The mean course of disease was (5.0±5.3) months. The best corrected visual acuity (BCVA), intraocular pressure and optical coherence tomography (OCT) were performed. BCVA was measured by Early Treatment Diabetic Retinopathy Study charts. Central macular thickness (CMT) was measured by OCT. The mean BCVA was (13.4±15.3) letters. The mean intraocular pressure (IOP) was (14.1±2.8) mmHg (1 mmHg=0.133 kPa). The mean CMT was (876.1±437.9) μm. Of the 39 eyes, 33 were central RVO, 6 were branch RVO. Patients were categorized into ischemic (18 eyes)/nonischemic (21 eyes) groups and previous treatment (22 eyes)/treatment naive (17 eyes) groups. All eyes underwent intravitreal 0.7 mg Ozurdex injections. BCVA, IOP and CMT were assessed at 1, 2, 3, 6, 9, 12 months after injection. Three months after injection, intravitreal injections of Ozurdex, triamcinolone acetonide or ranibizumab could be considered for patients with ME recurrence or poor treatment effects. Change of BCVA, IOP and CMT were evaluated with paired t test. The presence of ocular and systemic adverse events were assessed. Results BCVA, IOP significantly increased and CMT significantly decreased at 1 month after injection compared to baseline in all groups (t=3.70, 3.69, 4.32, 3.08, 4.25, 6.09, 6.25, 4.02, 5.49, 8.18, 6.54, 5.73; P 0.05); BCVA of non-ischemic RVO group and treatment naive group significantly increased compared to baseline (t=2.27, 2.30; P<0.05); IOP significantly increased and CMT significantly decreased in all groups (t=0.30, 0.13, 4.60, 3.26, 0.64, 1.53, 3.00, 4.87; P<0.05). Twenty-seven eyes (69.2%) experiences ME recurrence (4.5±1.5) months after injection. Most common side-effect was secondary glaucoma. 41.0% eyes had IOP more than 25 mmHg, most of which were lowered to normal range with use of topical IOP lowering drugs. Four eyes (10.3%) presented with significant cataract progression and needed surgical treatment, all were central RVO eyes. No serious ocular or systemic adverse events such as vitreous hemorrhage, retinal detachment or endophthalmitis were noted. Conclusions Intravitreal injection of Ozurdex for patients with ME secondary to RVO is effective in increasing BCVA and lowering CMT in the first few months. Significant treatment effect could be seen at 1 month after injection and was most significant at 2 months after injection. The long-term vision of eyes in non-ischemic RVO group and treatment naive group are better. 69.2% eyes experience ME recurrence at 4 months after injection. Short term adverse events were mostly secondary glaucoma and long term adverse events are mostly cataract progression. Key words: Dexamethasone/therapeutic use; Retinal vein occlusion/drug therapy; Macular edema/drug therapy