Evaluation of best corrected visual acuity and central macular thickness after intravitreal dexamethasone implant injections in patients with Irvine-Gass syndrome: A retrospective study of six cases

Purpose: Irvine-Gass syndrome is a macular edema (ME) that specifically occurs after cataract surgery. Its incidence varies from 0.2-2%. The purpose of this study is to evaluate the effectiveness of intravitreal dexamethasone implant injections in patients with Irvine-Gass syndrome.

Methods: Patients with ME secondary to cataract surgery who underwent intravitreal injections of dexamethasone implant between December 2011 to October 2014 at François-Quesnay hospital (Mantes-la-Jolie, France) were retrospectively reviewed. The patients were followed for at least 10 months. All the patients were handled by intravitreal injection of dexamethasone in the eye of study among which some resisted to a preliminary treatment by non-steroidal anti-inflammatory drug (NSAID) and acetazolamide. The patients were examined each month. The patients were again handled by intravitreal injection of dexamethasone if they presented a recurrence. The primary endpoint of the study was determined on best corrected visual acuity (BCVA) using early diabetic retinopathy study (ETDRS) scale and central macular thickness (CMT) [μm] using optical coherence tomography (OCT) 3 and 6 months after the first injection. Secondary endpoints were the number of recurrences, the number of injections, the duration average before the first recurrence, the BCVA 10 months after the first injection and the tolerance.

Results: Six eyes of six patients were studied. At baseline, the mean (standard deviation [SD]) of the BCVA was 59.8±11. Three months after the first injection, the mean (SD) of the BCVA showed a statistically significant increase to 72.2±8.6 (P=0.03). Six months after the first injection, the mean (SD) of the BCVA showed a statistically significant increase to 72±11.8 (P=0.03). Concerning the CMT, the mean (SD) was 495.6±135.2 before treatment. Three months after the first injection, the mean (SD) of the CMT showed a statistically significant decrease to 268.6±57.8 (P=0.03). Six months after the first injection, the mean (SD) of the CMT showed a significant decrease to 350.1±56.3 (P=0.09).

Conclusion: In this study, both mean BCVA and mean CMT had significantly improved from baseline after treatment with dexamethasone implant in patients with Irvine-Gass syndrome.