title: Anterior segment optical coherence tomography in the long-term follow-up and detection of glaucoma in Boston type I keratoprosthesis.
abstract: OBJECTIVE
  To evaluate the role of anterior segment (AS) optical coherence tomography (OCT) as a standardized method of imaging Boston type I keratoprosthesis (KPro) after surgery, particularly in the visualization of iris and angle structures.
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  Twenty patients who underwent KPro implantation in 1 eye.
  
  
  METHODS
  Patients underwent AS OCT imaging before surgery. After KPro implantation, patients were imaged using the AS single, dual, and quad scans to obtain transverse images of the eye every 15° over 360°. High-resolution, corneal quad, and anterior chamber scans were also obtained. This imaging protocol allowed juxtaposition and comparison of the same imaging coordinates obtained before surgery and 3, 6, and 12 months after surgery.
  
  
  METHODS
  Postoperative visual acuity (VA), glaucoma progression on clinical examination and formal visual field testing, and anatomic angle changes on AS OCT defined by angle closure, peripheral anterior synechiae (PAS), iris-KPro backplate touch, and graft-host interface changes over time.
  
  
  RESULTS
  Mean follow-up was 18.8±3.2 months. The average preoperative VA was 1.9±0.5 logarithm of the minimum angle of resolution. After surgery, VA improved to 1.0±0.9 at last follow-up (P = 0.002). Fourteen of 20 patients had glaucoma before surgery. After surgery, 5 of these patients deteriorated clinically and 1 de novo diagnosis of glaucoma was made. On OCT, the average total degrees of angle closure for all patients increased from 158.5±158.9° before surgery to 205.4±154.0° after surgery (P = 0.04). The number of eyes with 360° of PAS increased from 6 of 20 before surgery to 9 of 20 after surgery. Iris-backplate touch was demonstrated in 5 of 20 patients, with an average area of involvement of 24.2±36.2°. Overall, of the 12 of 20 patients with clear signs of anatomic angle narrowing and synechiae progression on imaging, 3 had glaucoma deterioration detected by clinical examination. In the other 9 patients, angle changes on OCT were not accompanied by any detectable clinical signs of glaucomatous deterioration.
  
  
  CONCLUSIONS
  Anterior segment OCT can be used to observe anatomic changes after KPro implantation that cannot be detected otherwise. We were unable to demonstrate a correlation between anatomic features and clinical progression.
authors.affiliation: Department of Ophthalmology, Université de Montréal, Québec, Canada; Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts.
authors.forename: Cynthia X
authors.initials: CX
authors.lastname: Qian
authors.affiliation: Department of Ophthalmology, Université de Montréal, Québec, Canada.
authors.forename: Salima
authors.initials: S
authors.lastname: Hassanaly
authors.affiliation: Department of Ophthalmology, Université de Montréal, Québec, Canada. Electronic address: monadagher@hotmail.com.
authors.forename: Mona
authors.initials: M
authors.lastname: Harissi-Dagher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000473:pathology*; D001705:Bioprosthesis; D003315:Cornea; D005260:Female; D005500:Follow-Up Studies; D015812:Glaucoma, Angle-Closure / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D019736:Prostheses and Implants; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology