PurposeTo evaluate the long-term effects of early postoperative intraocular pressure (IOP) after Ahmed glaucoma valve (AGV) implantation on long-term surgical outcomes.MethodsThis retrospective, non-randomized study included 100 eyes of 100 patients who underwent AGV surgery. We divided the enrolled patients into four groups according to the presence of transient hypotony within the first postoperative week or the presence of a hypertensive phase during the first three postoperative months. Postoperative IOP, the number of glaucoma medications, and cumulative success rate were compared among the groups.ResultsThere was significantly better IOP control and a better success rate in the non-hypertensive phase group 2 years postoperatively. However, no significant difference was found in the IOP or success rate at 2 years postoperatively between the transient hypotony and non-hypotony groups. Further subgroup analysis showed that the non-hypotony, non-hypertensive phase group had a significantly higher success rate (100%) at 2 years postoperatively.ConclusionsWe can predict the long-term prognosis after AGV implantation by considering the early postoperative IOP state and the presence of a hypertensive phase.