AN ULTRASOUND BIOMICROSCOPIC STUDY OF EYES AFTER DEEP SCLERECTOMY WITH COLLAGEN IMPLANT

Objective: This study aimed to assess the natural history of eyes afte r deep sclerectomy with collagen implant (DSCI), a nonperforating glau coma-filtering surgery. Design: The design was a prospective, longitud inal, observational, and nonrandomized study. Participants: Forty-five eyes of 41 patients with medically uncontrolled open-angle glaucoma w ere studied. Intervention: Deep sclerectomy with collagen implant was performed. Main Outcome Measures: Ultrasound biomicroscopy (UBM) of th e sclerectomy site was performed 1, 2, 3, 6, 9, 12, and 18 months afte r surgery. The following parameters were assessed: length and height o f the collagen implant, thickness of the residual trabeculodescemetic membrane, and bleb appearance. Results: Mean intraocular pressure decr eased from a preoperative value of 26.3 +/- 3.5 mmHg (mean +/- standar d deviation) to a postoperative value of 16.6 +/- 3.1 mmHg (mean +/- s tandard deviation) at 18 months (P < 0.001). The UBM findings showed a subconjunctival filtration with a nonperforated thin trabeculodesceme tic membrane. In 23 eyes (51%), a hypoechoic area in the suprachoroida l space was observed. The thickness of the trabeculodescemetic membran e was stable throughout the study with a mean value of 0.13 mm +/- 0.0 2 (mean +/- standard deviation) at 18 months. The collagen implant dis solved slowly within 6 to 9 months, leaving a tunnel in the sclera. Co nclusions: The UBM findings are consistent with intraocular pressure l owering by aqueous filtration through the thin remaining trabeculodesc emetic membrane to an area under the scleral flap, which was maintaine d open by the collagen implant. The authors speculate that aqueous hum or then reached the subconjunctival space and, eventually, was filtere d through the thin scleral wall into the suprachoroidal space. Complet e resorption of the collagen implant occurred between 6 and 9 months a fter surgery.