Enzymatic sclerostomy: Pilot human study
Archives of Ophthalmology
Objective: To evaluate the feasibility and safety of enzymatic sclerostomy as a new modality to lower intra-ocular pressure in patients with open-angle glaucoma. Methods: This single-center, prospective, noncomparative, interventional case series included 15 blind symptomatic eyes of 15 patients with primary open-angle glaucoma. Enzymatic sclerostomy was performed with the patient under topical or peribulbar anesthesia. A specially designed polymethylmethacrylate enzyme applicator filled with a mean±SD of 123±13 μg of collagenase was introduced through a 5-mm peritomy, and affixed to the limbus by means of cyanoacrylate tissue glue. After 22 to 24 hours, the applicators were removed and the patients were followed up for 1 year. Intraocular pressure changes from baseline and complications related to the procedure were the main outcome measures. Results: Controlled thinning of the treated sclera associated with aqueous percolation and shallow filtration bleb was seen in all eyes in the immediate postoperative period. The mean±SD intraocular pressure decreased from 43.5±9.8 mm Hg (while the patients were receiving a mean±SD of 1.75±0.75 antiglaucoma medications) preoperatively to 24.8±10.6 mm Hg (a 43.0% decrease from baseline with no antiglaucoma medication) on the first postoperative day and to 34.8±10.5 mm Hg (a 20.0% decrease from baseline with no antiglaucoma medication) at the end of 1 year. Ophthalmic adverse effects were limited to the treated area and included immediate post-operative transient conjunctival reaction ranging from mild chemosis to conjunctival maceration. Immediate full-thickness perforation developed in 1 eye; the patient was treated and excluded from data analysis. Two eyes developed symptoms related to increase in intraocular pressure after 9 months; the patients were treated and excluded from further data analysis. No systemic complications were noted. Conclusions: Enzymatic sclerostomy demonstrated immediate and sustained intraocular pressure reduction and provided symptomatic relief in blind eyes with primary open-angle glaucoma. The procedure, however, needs further technical refinement.
Dan, J., Honavar, S., Belyea, D., Mandal, A., Garudadri, C., Levy, B., Ramakrishnan, R., Krishnadas, R., Lieberman, M., Stamper, R., & Yaron, A. (2002). Enzymatic sclerostomy: Pilot human study. Archives of Ophthalmology, 120 (5). http://dx.doi.org/10.1001/archopht.120.5.548