title: Long-term Visual Outcomes and Complications of Boston Keratoprosthesis Type II Implantation.
abstract: To report the long-term visual outcomes and complications after Boston keratoprosthesis type II implantation in the largest single-center case series with the longest average follow-up.
  
  
  
  Retrospective review of consecutive clinical case series.
  
  
  
  Between January 1992 and April 2015 at the Massachusetts Eye and Ear Infirmary, 48 eyes of 44 patients had keratoprosthesis type II implanted by 2 surgeons (C.H.D. and J.C.).
  
  
  
  For each eye, data were collected and analyzed on the preoperative characteristics, intraoperative procedures, and postoperative course.
  
  
  
  Visual acuity outcomes, postoperative complications, and device retention.
  
  
  
  The most common indications for surgery were Stevens-Johnson syndrome in 41.7% (20 of 48 eyes) and mucous membrane pemphigoid in 41.7% (20 of 48 eyes). Mean follow-up duration was 70.2 months (standard deviation, 61.8 months; median, 52 months; range, 6 months to 19.8 years). Almost all patients (95.8%, 46 of 48 eyes) had a preoperative visual acuity of 20/200 or worse. Postoperative visual acuity improved to 20/200 or better in 37.5% (18 of 48 eyes) and to 20/100 or better in 33.3% (16 of 48 eyes) at the last follow-up visit. The most common postoperative complication was retroprosthetic membrane formation in over half (60.4%, 29 of 48 eyes). The most pressing postoperative complication was glaucoma onset or progression in about a third. Preexisting glaucoma was present in 72.9% (35 of 48 eyes). Glaucoma progressed in 27.1% (13 of 48 eyes) and was newly diagnosed in 8.3% (4 of 48 eyes) after surgery. Other postoperative complications were tarsorrhaphy revision in 52.1% (25 of 48 eyes), retinal detachment in 18.8% (9 of 48 eyes), infectious endophthalmitis in 6.3% (3 of 48 eyes), and choroidal detachment or hemorrhage in 8.3% (4 of 48 eyes). Half of eyes retained their initial keratoprosthesis at the last follow-up (50.0%, 24 of 48 eyes).
  
  
  
  The Boston keratoprosthesis type II is a viable option to salvage vision in patients with poor prognosis for other corneal procedures. Retroprosthetic membranes, keratoprosthesis retention, and glaucoma are major challenges in the postoperative period; however, the keratoprosthesis can still provide improved vision in a select group of patients.
authors.affiliation: Harvard Medical School, Boston, Massachusetts.
authors.forename: Ramon
authors.initials: R
authors.lastname: Lee
authors.affiliation: Glaucoma Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Ziad
authors.initials: Z
authors.lastname: Khoueir
authors.affiliation: Glaucoma Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Edem
authors.initials: E
authors.lastname: Tsikata
authors.affiliation: Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: James
authors.initials: J
authors.lastname: Chodosh
authors.affiliation: Cornea Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts.
authors.forename: Claes H
authors.initials: CH
authors.lastname: Dohlman
authors.affiliation: Glaucoma Service, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts. Electronic address: teresa_chen@meei.harvard.edu.
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D001187:Artificial Organs; D003316:Corneal Diseases / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000601:surgery; D006085:Graft Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000706:statistics & numerical data*; D060489:Prosthesis Retention / Q000706:statistics & numerical data; D012189:Retrospective Studies; D014792:Visual Acuity