title: Intermediate-term results of a randomized clinical trial of the 350- versus the 500-mm2 Baerveldt implant.
abstract: BACKGROUND
  The Baerveldt glaucoma implant is a large equatorial aqueous shunting device that is installed through a single-quadrant conjunctival incision. The intermediate-term results of a randomized study comparing the 350- and 500-mm2 Baerveldt implants are reported.
  
  
  METHODS
  Seventy-three patients with medically uncontrollable, nonneovascular glaucomas associated with aphakia, pseudophakia, or failed filters were enrolled in a randomized, prospective study comparing 350- and 500-mm2 Baerveldt implants. Surgical success was defined as 6 mmHg < or = final intraocular pressure < or = 21 mmHg without glaucoma reoperation or devastating complication.
  
  
  RESULTS
  Of patients with 350- and 500-mm2 implants, 93% and 88%, respectively, achieved surgical success (18-month life-table analysis, P = 0.93). The 500-mm2 implants afforded intraocular pressure control with significantly fewer medications (0.7 versus 1.3; P = 0.006). The postoperative visual acuities remained within one line of the preoperative visual acuities or improved in 62% and 66% of patients in the 350- and 500-mm2 groups, respectively (P = 0.93). Complication rates were statistically similar. The most frequent ones in the 350- and 500-mm2 groups, respectively, were serous choroidal effusion (16% and 32%), strabismus (16% and 19%), anterior uveitis (14% and 11%), and corneal or corneal graft edema (11% each).
  
  
  CONCLUSIONS
  The intermediate-term results of the 350- and 500-mm2 Baerveldt implants were statistically comparable with respect to surgical and visual outcomes, as well as complications, although the larger implant was associated with a higher rate of some complications. However, the 500-mm2 Baerveldt implant afforded intraocular pressure control with fewer medications than the 350-mm2 implant.
authors.affiliation: Department of Ophthalmology, University of Southern California School of Medicine, Los Angeles.
authors.forename: M A
authors.initials: MA
authors.lastname: Lloyd
authors.forename: G
authors.initials: G
authors.lastname: Baerveldt
authors.forename: P S
authors.initials: PS
authors.lastname: Fellenbaum
authors.forename: P A
authors.initials: PA
authors.lastname: Sidoti
authors.forename: D S
authors.initials: DS
authors.lastname: Minckler
authors.forename: J F
authors.initials: JF
authors.lastname: Martone
authors.forename: L
authors.initials: L
authors.lastname: LaBree
authors.forename: D K
authors.initials: DK
authors.lastname: Heuer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D004322:Drainage / Q000295:instrumentation; D005901:Glaucoma / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D019736:Prostheses and Implants; D016896:Treatment Outcome; D014463:Ultrasonography