Difference in the efficacy of intravitreal dexamethasone implant before and after silicone oil removal: A case report

Clinical Outcome of Cystoid Macular Edema in Silicone Oil-Filled Eyes

Purpose: To investigate the clinical outcome of cystoid macular edema (CME) in eyes undergoing silicone oil (SO) tamponade with subsequent SO removal (SOR). Methods: A retrospective case series of adult patients with CME treated with SO tamponade and SOR was conducted between January 2015 and January 2021. Exclusion criteria included eyes with a prior SO tamponade, those that did not undergo SOR, or those with infectious/inflammatory diagnoses. The primary outcomes were the incidence and resolution rates of CME in eyes with SO tamponade that had undergone SOR. The secondary outcomes included changes in best-corrected visual acuity (BCVA) and central field thickness (CFT). Results: Nineteen eyes of 19 patients (58% men) aged 52 years (interquartile range [IQR], 45-66 years) met the study inclusion criteria. The median (IQR) follow-up duration post SOR was 22 (8-35) months. The mean CFT decline for the CME-resolved cases was 13.1 µm/mo (P = .257). CME resolved in only 10 eyes (53%), 7 (67%) of which occurred after SOR. The median (IQR) BCVA was 20/400 (20/200 to 20/1262) at CME diagnosis and 20/796 (20/252 to hand motions) after SOR, with 0.184 worsening in logMAR BCVA (P = .340). Medical treatment was not associated with CME resolution compared with observation (50% vs 89%, respectively; P = .069). Eyes with proliferative vitreoretinopathy (PVR) had a higher rate of persistent CME compared with eyes with other diagnoses (78% vs 10%, respectively; P = .005). Conclusions: Nearly half had nonresolution of CME after SO was removed. The VA at the last follow-up was unaffected by CME resolution. Preoperative PVR may be a risk factor for unresolved CME.

Intravitreal Dexamethasone Implant at the Time of Silicon Oil Removal to Treat Persistent Macular Edema after Rhegmatogenous Retinal Detachment Repair

BACKGROUND

An intravitreal dexamethasone implant (DEX-I) was found to be effective and safe for the treatment of cystoid macular edema (CME) after vitrectomy for rhegmatogenous retinal detachment (RRD) and in silicone oil (SO)-filled eyes. We aimed to investigate the efficacy and safety of DEX-I at the time of SO removal for the treatment of recalcitrant CME after successful RRD repair.

METHODS

A retrospective review of the medical records was performed on 24 consecutive patients (24 eyes) with recalcitrant CME after RRD repair who were treated with a single 0.7-mg DEX-I at the time of SO removal. The main outcome measures were changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT). A regression model was performed to assess the relationship between BCVA and CMT at 6 months and independent variables.

RESULTS

In all 24 patients, CME occurred after RRD repair and remained despite topical therapy. The mean time of CME onset was 27.4 ± 7.7 days after vitrectomy. The mean time between vitrectomy and DEX-I was 106.8 ± 10.1 days. The mean CMT was significantly decreased from 429.6 ± 59.1 µm at baseline to 294 ± 46.4 µm at month 6 (p < 0.0001). The mean BCVA significantly improved from 0.99 ± 0.3 at baseline to 0.60 ± 0.3 at month 6 (p < 0.0001). An elevation of intraocular pressure was observed in one (4.1%) eye, which was medically managed. A univariate regression model revealed a relationship between month-6 BCVA after DEX-I and gender (β = -0.27; p = 0.03) and macular status (β = -0.45; p = 0.001) when RRD occurred. No relationship between month-6 CMT and independent variables was found.

CONCLUSIONS

DEX-I at the time of SO removal had an acceptable safety profile and achieved favorable outcomes in eyes affected by recalcitrant CME that occurred after RRD repair. RRD-related macular status is significantly associated with visual acuity after DEX-I.