Anatomical and functional recurrence after dexamethasone intravitreal implants: a 6-month prospective study

To evaluate the efficacy, safety, and delay of anatomical and functional recurrence after a first intravitreal injection of dexamethasone implant in eyes with cystoid macular edema (CME) secondary to retinal vein occlusion (RVO).

A 6-month prospective, monocentric and noncomparative case-series of 26 eyes of 26 patients. Best-corrected visual acuity (BCVA) and central subfield thickness (CST) were measured at baseline and each visit at 1 week, and months 1, 2, 3, 4, 5, and 6 after a first treatment. Primary efficacy outcome was the proportion of eyes with a minimum three-line improvement from baseline BCVA at each visit and at 6 months. We also defined different patterns of recurrence: qualitative anatomical recurrence, quantitative anatomical recurrence and functional recurrence. A P-value <5% was considered statistically significant.

Mean population age was 69.3 years (SD=12.2; range=42-94 years). Mean ME duration before treatment was ~9.2 months (SD=11.43; range=0.4-40 months). Eighty eight percent of eyes achieved a three-line improvement from baseline at 2 months (P=0.02). The mean delay from baseline until qualitative anatomical, functional, or quantitative anatomical recurrence was 4.11 months (±0.86), 4.31 months (±1.33), and 4.40 months (±1.14), respectively. Qualitative anatomical recurrence occurred on average 14.4 days (SD=42.18) before a minimum of one-line BCVA impairment (functional recurrence).

Dexamethasone intravitreal treatment seems to be effective for ME after RVO even with long-duration ME or poor visual acuity before treatment. Other longer studies should assess the delay of recurrence after second and further treatments with DEX implants or combined therapies for ME after RVO.