Trabeculectomy: is releasable suture trabeculectomy a cause of better bleb?

Purpose: To compare the outcome of fixed suture trabeculectomy with releasable suture trabeculectomy in terms of IOP control, bleb morphology, complications and need of antiglaucoma medication post-surgery.

Methods

This study enlisted 200 cases of open angle glaucoma, whose IOP was uncontrolled despite maximal medication. Trabeculectomy was performed using releasable suture in one group of 100 patients and fixed suture in another group of 100 with mitomycin 0.02% in both groups. The study was randomized, the method being the simple randomization. Fornix based trabeculectomy was done in both groups. Two 10-0 nylon releasable sutures were used at two corners of the rectangular flap and one fixed 10-0 vicryl suture was used in the center of the flap. Two mattress sutures (conjunctiva cornea) were also used. Essentially, all the sutures were removed postoperatively over a period of 2-4 weeks depending upon the level of IOP. Mitomycin c 0.02% was used in both groups.

Results

The mean preoperative intraocular pressure was 33 ± 12 mmHg in the single suture group and 39 ± 13 mmHg in the releasable suture group (p). We observed a highly significant reduction of intraocular pressure at all times in both groups compared with the preoperative intraocular pressure (P, 0.0001). There was an obvious difference between the bleb morphology between conventional trabeculectomy and releasable suture trabeculectomy. Blebs in releasable suture trabeculectomy were more diffuse, low lying and presented a more ideal vascularity.

Conclusion

Releasable suture trabeculectomy is a far much better technique than conventional trabeculectomy. Results are very good in terms of IOP control, post-operative complications, and bleb morphology. They may possibly have a role in wound modulation thereby achieving an ideal bleb, though more large sample studies need to be done.