Amniotic Membrane Transplantation Improves the Mid–Term Outcome of Filtration Surgery for Intractable Glaucoma

Abstract

Abstract: : Purpose:To evaluate the effectiveness of amniotic membrane transplantation (AMT) as an adjunct to filtration surgery for intractable glaucoma. Methods:Retrospective review of the records of 19 consecutive eyes of 16 patients with glaucoma who underwent filtration surgery with or without AMT after repeated filtration surgeries was conducted. Trabeculectomy or bleb revision with AMT was performed on 11 eyes of 10 patients (group A), whereas conventional trabeculectomy without AMT on 11 eyes of 10 patients (group B). Since 3 eyes included in group B eventually underwent filtration surgery with AMT, they were also included in group A. The number of prior glaucoma filtration surgeries in group A and B was 2.7±1.2 (1–5) and 3.1±1.0 (2–5), respectively (p=0.49). In group A, trabeculectomy or bleb revision with limbal–based conjunctival flap using 0.4mg/ml mitomycin–C was performed. Then AM was placed between sclera and conjunctiva with the epithelial side up. Limbal side of AM was sutured with sclera and fornix side with Tenon’s capsule, respectively. In group B, trabeculectomy was similarly performed except for AMT. All eyes were followed up for at least 12 months and mean of 16.6±5.9 months. Postoperative intraocular pressure (IOP) and the number of antiglaucoma medications of every month and the bleb appearance at final visit were studied. Success was defined as an IOP less than 22mmHg regardless of the use of ocular hypotensive medication or needle revision of bleb. Kaplan–Meier analysis was performed in assessing cumulative IOP success. Mann–Whitney U test was used as a statistic analysis for IOP, number of medication, and success rate of each follow–up period comparison. The bleb appearance was analyzed with Fisher’s exact probability test. P<0.05 was judged as significant. Results:At 12–month follow–up period, mean IOP of group A and B was 12.6±5.7mmHg and 18.3±6.5mmHg (p=0.19) and mean number of antiglaucoma medication was 0.89±1.56 and 1.20±1.07(p=0.23), respectively. Cumulative survival rate of Kaplan–Meier analysis at 12–month follow–up period was 81.8% in group A and 45.5% in group B. However there was also no significance probably because of small sample size. In group A 8 eyes had diffuse bleb and 3 eyes had failed bleb such as encapsulated or flat bleb, while 8 eyes in group B had failed bleb (p=0.03). Conclusions:AMT may improve the IOP control and maintain diffuse bleb after filtration surgery for intractable glaucoma.

Keywords: wound healing