title: An ultrasound biomicroscopic study of eyes after deep sclerectomy with collagen implant.
abstract: OBJECTIVE
  This study aimed to assess the natural history of eyes after deep sclerectomy with collagen implant (DSCI), a nonperforating glaucoma-filtering surgery.
  
  
  METHODS
  The design was a prospective, longitudinal, observational, and nonrandomized study.
  
  
  METHODS
  Forty-five eyes of 41 patients with medically uncontrolled open-angle glaucoma were studied.
  
  
  METHODS
  Deep sclerectomy with collagen implant was performed.
  
  
  METHODS
  Ultrasound biomicroscopy (UBM) of the sclerectomy site was performed 1, 2, 3, 6, 9, 12, and 18 months after surgery. The following parameters were assessed: length and height of the collagen implant, thickness of the residual trabeculodescemetic membrane, and bleb appearance.
  
  
  RESULTS
  Mean intraocular pressure decreased from a preoperative value of 26.3 +/- 3.5 mmHg (mean +/- standard deviation) to a postoperative value of 16.6 +/- 3.1 mmHg (mean +/- standard deviation) at 18 months (P < 0.001). The UBM findings showed a subconjunctival filtration with a nonperforated thin trabeculodescemetic membrane. In 23 eyes (51%), a hypoechoic area in the suprachoroidal space was observed. The thickness of the trabeculodescemetic membrane was stable throughout the study with a mean value of 0.13 mm +/- 0.02 (mean +/- standard deviation) at 18 months. The collagen implant dissolved slowly within 6 to 9 months, leaving a tunnel in the sclera.
  
  
  CONCLUSIONS
  The UBM findings are consistent with intraocular pressure lowering by aqueous filtration through the thin remaining trabeculodescemetic membrane to an area under the scleral flap, which was maintained open by the collagen implant. The authors speculate that aqueous humor then reached the subconjunctival space and, eventually, was filtered through the thin scleral wall into the suprachoroidal space. Complete resorption of the collagen implant occurred between 6 and 9 months after surgery.
authors.affiliation: Hôpital Ophtalmique Jules Gonin, Department of Ophthalmology, University of Lausanne, Switzerland.
authors.forename: A G
authors.initials: AG
authors.lastname: Chiou
authors.forename: A
authors.initials: A
authors.lastname: Mermoud
authors.forename: J P
authors.initials: JP
authors.lastname: Underdahl
authors.forename: C C
authors.initials: CC
authors.lastname: Schnyder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging; D003094:Collagen; D005260:Female; D005902:Glaucoma, Open-Angle / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D006801:Humans; D007429:Intraocular Pressure; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019736:Prostheses and Implants; D012590:Sclera / Q000000981:diagnostic imaging / Q000601:surgery; D012599:Sclerostomy; D013524:Surgical Flaps; D014463:Ultrasonography
chemical_list: D003094:Collagen