Ahmed Valve for Secondary Glaucoma in Patients with Hereditary Transthyretin Amyloidosis

Objective To evaluate the surgical outcomes of patients with hereditary transthyretin amyloidosis (TTR-FAP) who underwent Ahmed glaucoma valve (AGV) implantation. Methods A retrospective cohort study was performed on patients with a diagnosis of TTR-FAP secondary glaucoma, who underwent AGV implantation in our department, between November 2010 and July 2019. The cumulative probability of treatment success was measured with Kaplan-Meier survival analysis. The primary outcome was success, defined as intraocular pressure (IOP) ≥ 6 mmHg and ≤21 mmHg with or without medication, with no need for further glaucoma surgery and without loss of light perception at last follow-up. Secondary outcomes were postoperative IOP, number of IOP-lowering medications, and rates of complications. Results The study included 114 eyes of 87 patients. The mean follow-up duration was 3.81 ± 2.11 years (y) [range, 1.00–8.28 y]. Compared to the preoperative values, the mean IOP was reduced from 28.20 ± 7.01 to 12.87 ± 3.76 mmHg at the final visit ( p < 0.001), with a reduction in the number of medications from 3.89 ± 0.66 to 1.86 ± 1.43 ( p < 0.001). Early and late postoperative complications occurred in 20 (17.09%) and 9 (7.89%) eyes, respectively. Kaplan–Meier analysis indicated probabilities of success of 0.98 at 1 y, 0.97 at 2 y, 0.95 at 3 y, 0.89 at 4 y, 0.77 at 5 y and 0.72 at 6 y. The linear correlation analysis showed a correlation between some characteristics of the natural history of TTR-FAP patients and AGV implantation success. Conclusion Although glaucoma in TTR-FAP patients is very difficult to manage, AGV implantation is an effective and relatively safe procedure.