Abstract
Abstract: :
A Prospective Randomized Clinical Trial of the Ahmed Valve Bi–plate with the Double Plate Molteno Implant: Study Design and Results of the Initial 74 Patients Purpose:Very few prospective randomized trials have been conducted comparing glaucoma drainage devices. This study was undertaken to compare two similar devices, the Ahmed Valve bi–plate with the Double Plate Molteno implant. The primary differences between the two are the presence of a flow restrictor ("valve") in the Ahmed device, and the somewhat larger total surface area of the Ahmed device. This presentation is intended to describe the study design and report the results of the first 74 patients (of 129) enrolled. Methods: This 1 year study was performed in a private referral glaucoma practice with a single surgeon. After obtaining informed consent, patients were randomized to implantation of the Ahmed or the Molteno implant. If a patient required drainage implants in both eyes, the second eye received the other device. Age, sex, glaucoma diagnosis, ethnicity and systemic illnesses were noted. Identical surgical technique and post operative management was used in both groups. Visual Acuity, IOP, and number of glaucoma medications were recorded at pre–op, 3 months, 6 months, 1 year and at the most recent visit. Complications were recorded. Maximum IOP at the hypertensive phase was also noted. Results:129 patients were enrolled and randomized. The results of the first 74 patients one year following the implantation were: Ahmed: n=33, age 67.4 ± 12.6, COAG 3, Uveitic 3, Traumatic 1 Neovascular 18, CAC 8. Pre–op IOP averaged 43 ±17 mm Hg with 3.39 ± 1.12 medications. 13 patients completed one year follow up (all others lost to follow up) Average IOP at last visit: 16.57±5.9 using 1,82 meds .Hypotony 3 Molteno: n=41, age 69.8±13.7, COAG 2, Uveitic 3, Neovascular 25, CAC 8. Pre–op IOP 47±16 mm Hg with 3.34 ±1.26 meds. 14 patients completed one year. Avg IOP at last visit 18.21±9.32 using 1.5 meds. Hypotony 10 Conclusions:Both devices lowered pressure significantly. Most required post operative glaucoma medication to maintain adequate IOP. In this preliminary analysis, the Ahmed bi–plate implant lowered IOP slightly better than the Molteno double plate. Remarkably few of the initial 74 enrolled patients (36%) returned for the required follow up visits.
Keywords: intraocular pressure • anterior segment • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled