Ahmed glaucoma valve and single-plate Molteno implants in treatment of refractory glaucoma: a comparative study.

PURPOSE: To report 2-year follow-up data after Ahmed valve implantation (New World Medical, Inc) and Molteno single-plate implantation surgical treatment of refractory glaucoma. DESIGN: Prospective, randomized, comparative study. METHODS: Patients with refractory glaucoma, defined as uncontrolled intraocular pressure (IOP) of more than 21 mm Hg despite maximal antiglaucoma medication, previously failed nonseton surgical treatment, or a combination thereof were included. Ninety-two patients were allocated randomly to each of the study groups and underwent implantation of either the Ahmed valve implant (model FP7; 184 mm(2) surface area) or Molteno single-plate implant (134 mm(2) surface area) and were followed up for 24 months. Main outcome measures were IOP and surgical success rate. Other outcome measures were changes in visual acuity, number of ant-glaucoma medications, mean deviation of visual field, and rate of intraoperative and postoperative complications. RESULTS: Those who successfully completed the trial (28 in the Molteno group and 29 in the Ahmed group) achieved significantly less IOP and fewer glaucoma medications, but worse visual acuity 24 months after surgery. The Molteno group, compared with the Ahmed group, achieved significantly lower IOPs after the early postoperative period until the end of the study. Both groups reasonably maintained visual field during the follow-up. The rate of surgical failure was comparable in both groups. Median survival time was 24 months for both groups. There were no devastating intraoperative or postoperative complications in either group. CONCLUSIONS: Both Ahmed and Molteno implants successfully preserved visual field, although IOP control was more pronounced in the Molteno implant group.

Comparison of 2 surgical techniques in phacotrabeculectomy: 1 site versus 2 sites.

PURPOSE: To compare 1-site and 2-site phacotrabeculectomies with regard to visual acuity, intraocular pressure (IOP) control, antiglaucoma medication requirements, and postoperative complications. METHODS: In a randomized controlled trial, 169 eyes with coexisting visually significant cataract and glaucoma were randomly allocated into 2 groups: eyes that had a trabeculectomy in a superior quadrant combined with phacoemulsification through the same incision (1-site group; n=85) or those with a separate, temporal, clear corneal incision for phacoemulsification (2-site group; n=84). Postoperative evaluation, including visual acuity, intraocular pressure (IOP), glaucoma medication requirements, and surgical complications, was for up to 18 months. RESULTS: After 18 months, there was no significant difference between the 2 groups with respect to visual acuity and antiglaucoma medication requirements. There was a 0.6 to 1.4 mmHg difference in mean IOP, with the 2-site technique demonstrating statistically significant advantage over the 1-site technique in some follow-up visits with nonparametric analysis; however, the difference cannot be clinically significant. Success rates (IOP<21 mmHg with the maximum use of medication) of 1-site and 2-site groups were 85.9% and 92.8%, respectively, which was not statistically significant (p=0.153). Nevertheless, the incidence of failure in the 1-site group was almost twice that of the 2-site group (12 vs 6). Postoperative complications were comparable in both groups. CONCLUSIONS: Results for 18-month follow-ups of 1-site and 2-site phacotrabeculectomies were comparable in terms of visual acuity, antiglaucoma medication requirements, and postoperative complications. While lowering of IOP was more pronounced in the 2-site group, this was not clinically significant.

A comparison of corneal endothelial cell changes after 1-site and 2-site phacotrabeculectomy.

PURPOSE: To compare the corneal endothelial cell (CEC) changes that occurred after phacotrabeculectomy performed at 1 or 2 sites. DESIGN: A historical cohort study. METHODS: The records of patients who had 1-site (n = 61) or 2-site (n = 52) limbus-based phacotrabeculectomy over a 4-year period (2002-2005) at 1 eye surgery center (Vanak Eye Surgery Center, Tehran, Iran) by a single surgeon were reviewed, and postoperative CEC indices were measured. Preoperative CEC indices, performed for a then-ongoing trial, were compared with postoperative measurements of the last follow-ups. The main outcome measure was endothelial cell count. RESULTS: The median follow-up time was 12 months (range 9-24 months). There was no difference between the operations in improving visual acuity, lowering intraocular pressure, and decreasing the number of antiglaucoma medications required. However, 2-site surgery was associated with significantly more expansion in the CEC area (P < 0.001). On multivariate analysis, longer follow-up, 2-site surgery, and grade 4 cataract density were independently associated with more CEC loss, and longer follow-up, 2-site surgery, and steroid-induced glaucoma were associated with CEC area expansion. Postoperative complications were not markedly different between the 2 groups. CONCLUSIONS: In both groups, the longer the follow-up time was, the higher the CEC loss and the CEC area expansion were. One-site surgery seems to cause less CEC damage than the 2-site operation during the median follow-up time of 1 year.

Corneal endothelial cell injury induced by mitomycin-C in photorefractive keratectomy: nonrandomized controlled trial.

PURPOSE: To evaluate the effect of intraoperative use of mitomycin-C (MMC) on the corneal endothelium during excimer laser photorefractive keratectomy (PRK). SETTING: Vanak Eye Surgery Center, Tehran, Iran. METHODS: This nonrandomized trial comprised 81 patients (162 eyes) with bilateral low to moderate myopia and adequate corneal thickness to allow PRK (estimated postoperative residual stromal thickness >350 microm without considering epithelial thickness). The indication for intraoperative application of MMC 0.02% (0.2 mg/mL) was an ablation depth of 75 microm or more. Patients were divided into 3 groups: bilateral (both eyes treated with MMC), unilateral (only 1 eye treated with MMC), and untreated (no eye treated with MMC). Visual acuity, refraction, endothelial cell density (ECD), and corneal thickness were measured preoperatively as well as 1 week and 1, 3, and 6 months postoperatively. RESULTS: Overall, 76 eyes were treated with MMC. Eyes treated with MMC and untreated eyes were comparable in postoperative visual acuity and refraction. Preoperative to postoperative changes in ECD were statistically significantly greater in the treated eyes (-14.8%) than in untreated eyes (-5.1%) 6 months after PRK (P<.001). Longer MMC contact time (P<.001) and male sex (P= .04) were the only factors independently associated with greater endothelial cell loss. CONCLUSIONS: The prophylactic use of diluted intraoperative MMC 0.02% solution caused corneal endothelial cell loss. The rate of cell loss was correlated with the duration of MMC exposure.