Risk factors for hypertensive phase after Ahmed glaucoma valve implantation.

Abstract

To investigate the risk factors and the clinical characteristics of the hypertensive phase (HP) after Ahmed glaucoma valve (AGV) implantation. This retrospective study included 60eyes of 57 patients who underwent AGV implantation and with at least 1-year follow-up. HP was defined as intraocular pressure (IOP) > 21mmHg in the first 3months after the surgery. Independent samples t-test and Chi-square test were used to compare differences in patients with the HP and the non-HP groups. Univariable and multivariable logistic regression analyses were used to determine the risk factors for the development of the HP. Statistical significance was assumed at p < 0.05 level. HP was observed in 31 eyes (51.7%) with an average peak IOP of 27.6 ± 4.5mmHg (range 22-40mmHg). The resolution of HP was noted in 27eyes (87.1%) at the 3rd month postoperative visit. The number of glaucoma medications at the last postoperative visit and IOP values from 1month to 1year were significantly higher in the HP group (all p < 0.05). Patients with traumatic glaucoma showed the highest rate (83.3%) of HP development. In the multivariable analysis, a preoperative IOP > 30mmHg (p = 0.03, OR:5.82; reference: ≤ 25mmHg) and younger age (41-64years, p = 0.02, OR:8.49; ≤ 40years, p = 0.001, OR:19.62; reference: ≥ 65years) were independently associated with the occurrence of HP. Hypertensive phase was observed in half of the patients undergoing AGV implantation. A higher mean preoperative IOP and younger age were risk factors for HP development. Although the majority resolved at the 3-month visit, eyes with HP had higher mean IOPs and required more IOP lowering medications.