Abstract
Purpose:
Glaucoma drainage devices (GDD) are frequently used to control intraocular pressure (IOP) in complicated or refractive glaucomas. After implantation, the IOP typically undergoes a hypertensive phase (HP). The reason for this transient rise in IOP is poorly understood and can cause further damage to the optic nerve. The purpose of this study was to prospectively investigate the effectiveness of glaucoma medical therapy in preventing the HP following a GDD procedure.
Methods:
Patients who underwent a GDD procedure were monitored every week for 1 month and every month for 6 months postoperatively. HP was defined as an IOP > 21mmHg during the first 3 months after surgery. Patients were randomized to receive aqueous suppressants (including beta-blockers, alpha-agonists, or carbonic anhydrase inhibitors) when the postoperative IOP was >10mmHg (early-treatment group) or when the postoperative IOP was >17mmHg (standard-treatment group). Outcome measures included the occurrence of HP and IOP control.
Results:
53 eyes (50 patients) received a GDD, with a mean age of 64.1±13.8 years and 49.1% of patients Caucasian. Preoperative IOP was 26.3±8.6mmHg. HP was observed in 20 eyes (38.8%) with average peak IOP of 28.7±6.6mmHg. There were no significant differences between the early-treatment group (n=26 eyes) and standard-treatment group (n=27 eyes) with regard to the occurrence of HP (34.6% and 40.7%, respectively) or the average peak IOP (27.1±5.9 and 31.0±7.5mmHg, respectively). No eyes in the early-treatment group and two eyes in standard-treatment group required additional glaucoma surgery within 6 months postoperatively. Medical therapy initiated prior to the development of HP was not associated with hypotony (defined as IOP < 6 mmHg) or maculopathy.
Conclusions:
Medical therapy with topical aqueous suppressants initiated before the expected HP is comparable to standard treatments used to reduce the occurrence of HP after GDD procedure. It is not associated with hypotony even if the therapy was initiated when the postoperative IOP was already low. The effect of early treatment did not differ significantly between starting the topical therapy when the postoperative IOP was in the low versus high teens.
Keywords: 568 intraocular pressure •
466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials