Study of efficacy and timing of laser suture lysis in reducing intraocular pressure after trabeculectomy with mitomycin-C

Abstract

Context: Laser suture lysis is used to enhance filtration after trabeculectomy. Aims: The aim of this is to evaluate the change in intraocular pressure (IOP) after laser suture lysis after trabeculectomy with mitomycin-C and to correlate the efficacy of suture lysis in relation to the time of lysis. Settings and design: Prospective interventional study of seventy eyes of seventy patients. Subjects and methods: Trabeculectomy with mitomycin-C was performed for 352 patients with glaucoma. Laser suture lysis was carried out when indicated for seventy patients during 2nd-8th week posttrabeculectomy. Primary outcome measures were IOP at immediate postsuture lysis, 1, 2, 4, 6, and 8 weeks, 3 and 6 months following laser suture lysis. For the purpose of statistical analysis, patients were divided into three groups depending on the week of suture lysis as <3 weeks, 3rd-5th week, and >5 weeks posttrabeculectomy and 21 mmHg was used as the cutoff for the achievement of target IOP. Statistical analysis used: Descriptive statistical analysis has been carried out. Significance is assessed at 5% level of significance. Student's t-test (two-tailed, independent) has been used to find the significance of study parameters on continuous scale between two groups. Chi-square/Fisher exact test has been used to find the significance of study parameters on categorical scale between two or more groups. Results: On immediate postsuture lysis, 62 patients (88.6%) had IOP of <21 mmHg which increased to 68 patients (98.6%) at the end of 6 months postsuture lysis. When laser suture lysis was performed during 3rd-5th week posttrabeculectomy, 34 patients (73.9%) achieved the target IOP. Conclusions: Laser suture lysis during 3rd-5th week posttrabeculectomy with mitomycin-C is an effective and safe technique for reducing IOP.

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