Intravitreal dexamethasone implant for recalcitrant cystoid macular edema secondary to retinitis pigmentosa: a pilot study

To determine the utility of the intravitreal dexamethasone implant as therapy for cystoid macular edema (CME) secondary to retinitis pigmentosa (RP) recalcitrant to carbonic anhydrase inhibitor therapy over 2 years as a pilot study.

This was a prospective case series. Patients who showed either an incomplete or no response to topical dorzolamide for at least 1 month and oral acetazolamide therapy for at least 15 days were recruited for the study with informed consent. A complete anterior and posterior segment examination was performed including fundus fluorescein angiography (FFA), optical coherence tomography scan (OCT) and electroretinogram to confirm the diagnosis. The dexamethasone implant was injected using a standardized technique. Follow ups were scheduled on days 1, 7, and 30 and then monthly thereafter for 2 years. The primary outcome measure was the change in corrected distance visual acuity (CDVA) and central subfield thickness (CST) at months 1, 6, 12, 18, and 24. The secondary outcome measure was complications, if any. Appropriate statistical analysis was done.

Five patients (two males; six eyes; median age 49 years) were recruited for the study. All patients required at least two injections over 2 years. All patients demonstrated significant improvement in CDVA (p = 0.004) as well as CST measurements (p = 0.0038) over 2 years. No complications were noted.

The intravitreal dexamethasone implant provides significant improvement in CDVA and CST measurements in patients with recalcitrant CME secondary to RP.