EFFICACY OF DEXAMETHASONE INTRAVITREAL IMPLANT FOR REFRACTORY MACULAR EDEMA CAUSED BY RETINAL VEIN OCCLUSION

Abstract

To investigate efficacy of dexamethasone intravitreal (DEX) implant in treating refractory macular edema caused by retinal vein occlusion. Retrospective chart review. Twenty-two eyes with refractory macular edema caused by retinal vein occlusion were treated with a mean of 2.2 DEX over 12 months. Patient had previously received a mean of 7 treatments (laser, bevacizumab, and/or triamcinolone) for macular edema present for at least 4 months duration (mean 20.8 ± 17.6 months, range 4-72 months) before starting DEX. Mean baseline visual acuity was 20/91, and mean central subfield thickness was 506 μm. DEX improved mean best-corrected visual acuity to 20/75 and 20/66 at 7 weeks and 6 months follow-up, although it worsened to 20/132 at 12 months. Mean central subfield thickness improved to 292, 352, and 356 μm at 7 weeks, 6 months, and 12 months follow-up, respectively. There was a statistically significant association between number of DEX treatments and central subfield thickness (P = 3.28 × 10). There was a statistically significant association between number of days followed and best-corrected visual acuity (P = 0.006). Six of 12 (50%) phakic patients developed visually significant cataract requiring surgery. Five of 22 (23%) patients developed ocular hypertension (intraocular pressure > 30) and consequently did not undergo further treatment with DEX. DEX resulted in sustained anatomical reduction of retinal vein occlusion-associated refractory macular edema, although this did not translate into long-term best-corrected visual acuity improvement in either phakic or pseudophakic patients, possibly related to chronic structural alterations in the retina despite reduction of edema.