Incidence, outcomes, and risk of surgical failure after development of early hypotony following Aurolab aqueous drainage implant surgery

PURPOSE: To report the incidence, outcomes, and risk of surgical failure after early postoperative hypotony following Aurolab Aqueous Drainage Implant (AADI) surgery for adult and pediatric refractory glaucoma. METHODS: Medical records of patients who underwent AADI between January 2013 and March 2017 with a minimum of 2-years follow-up were retrospectively reviewed. Early postoperative hypotony was defined as IOP ≤5 mmHg within the first 3 months after AADI. Surgical failure of AADI was defined as IOP >21 mmHg or reduced <20% below baseline on two consecutive follow-up visits after 3 months, IOP ≤5 mmHg on two consecutive follow-up visits after 3 months, reoperation for glaucoma or a complication, or loss of light perception vision. RESULTS: Early postoperative hypotony was seen in 15/213 eyes (7%) in the adult group and in 6/101 eyes (6%) in the pediatric group. The onset of hypotony was significantly earlier in the pediatric group (median = 39 days post AADI, IQR = 20–58 days) compared with adult eyes (median = 51 days post AADI, IQR = 30–72 days) (P = 0.02). Eyes with early postoperative hypotony did not have an increased risk of cumulative surgical failure as compared with eyes without hypotony in both adult (33.3% vs. 23.7%; P = 0.48) and pediatric (33.3% vs. 13.7%; P = 0.16) refractory glaucoma. All eyes recovered from hypotony, though one adult eye developed retinal detachment and one pediatric eye developed corneal decompensation and lost vision. CONCLUSION: Early postoperative hypotony was an infrequent complication post AADI and occurred earlier in pediatric eyes. Early postoperative hypotony did not increase risk of surgical failure up to 2 years.