Antihypertensive therapy following glaucoma valve implantation: analysis of the effectiveness of carbonic anhydrase inhibitors and prostaglandin analogues

Abstract

Introduction. The Ahmed glaucoma valve (GV) type drainage implantation is characterized by high efficiency and low complication rate, and is finding an increasing application in clinical practice. Although GV provides better intraocular pressure (IOP) control and higher surgical success rates compared to trabeculectomy, the so-called hypertensive phase (HP), typically defined as an IOP elevation more than 21 mmHg, can occur at the period from one to three months postoperatively, related to the fibrous capsule reservoir formation, which does not have the character of persistent hypertension.Aim. To analyze the effectiveness of the Dorzolamide-Optic carbonic anhydrase inhibitor and the Latanoprost-Optic prostaglandin analogue as the drugs of choice in clinical conditions at different periods during postoperative follow-up when antihypertensive therapy after GV implantation is needed.Materials and methods. The study included 80 glaucoma patients who underwent GV implantation in the clinic “Eye Surgery Rascheskov” with a postoperative follow-up period of at least one year. In order to increase the effectiveness of surgical intervention and preserve visual functions, hypotensive therapy was prescribed in studied patients either when IOP exceeded the target pressure, or when there was a tendency to a constant increase between control visits. 180 operated patients with IOP level within the target level during the follow-up period were excluded from the study.Results. The overall incidence rate of the hypertensive phase (GF) was 44.4%. In all studied patients to compliance with the operation technique and early therapy appointment, Dorzolamide-Optic monotherapy was sufficient to achieve stabilization of visual functions for up to 3 months after surgery. During a follow-up period more than 3 month, 15 patients (18.8%) required additional appointment of Latanoprost-Optic to achieve the target IOP level. After 2 months following the implantation, the antihypertensive therapy was discontinued under the IOP control in 17 patients (21.3%).Conclusions. Medical management of HP is crucial for preventing further optic nerve damage and preserving visual functions, as reduction of the incidence and severity of HP are known to be associated with higher operative success rates and a better long-term IOP control.