■ Writing in the journal Ophthalmology, Felipe A. Medeiros, MD, PhD, and colleagues reported on their 20-month study of the bimatoprost implant (Durysta; Allergan, an AbbVie company). The researchers evaluated its safety and efficacy in reducing IOP in subjects with open-angle glaucoma (OAG) and ocular hypertension (OHT), after initial and subsequent administrations.

The randomized, multicenter, parallel-group, phase 3 clinical study examined adults with OAG or OHT in each eye, open iridocorneal angle inferiorly in the study eye, and a study eye baseline IOP (hour 0; 8 am) of 22 mmHg and 32 mmHg after washout. The Durysta implant releases its prostaglandin analog steadily for 90 days, stimulating the outflow of aqueous humor and reducing IOP.

Study eyes were implanted with Durysta dosed at 10 μg (n=198) or 15 μg (n=198) on day 1 and then readministered at 16 weeks and 32 weeks, or topical timolol maleate 0.5% (n=198) 2 times per day. Researchers measured each participant’s IOP at hours 0 and 2 at each visit. Both Durysta dosage strengths were noninferior to timolol in reducing IOP after administration. The incidence of corneal endothelial cell loss and iritis was higher with Durysta than with timolol, and higher with the 15-μg dose than the 10-μg dose. Corneal treatment-emergent adverse events increased with repeated treatment, but mean BCVA was stable.

Researchers found that a year after treatment, most subjects showed controlled IOP, and the 10-μg implant produced a better risk-benefit assessment than the 15-μg implant. They also concluded that the implant can potentially improve medication adherence and reduce the glaucoma treatment burden for both patients and doctors. Studies are ongoing to find ways to reduce the chances of corneal endothelial cell density loss by altering the drug’s administration regimen.