title: Use of anterior segment optical coherence tomography to assess secondary glaucoma after penetrating keratoplasty.
abstract: OBJECTIVE
  To describe the use of anterior segment optical coherence tomography (AS-OCT) in the evaluation of a patient with raised intraocular pressures after penetrating keratoplasty.
  
  
  METHODS
  A 52-year-old Indian male with bilateral keratoconus underwent multiple penetrating keratoplasties because of repeated episodes of endothelial rejection and graft failure. He also had secondary glaucoma bilaterally for which he underwent bilateral posterior implantation of glaucoma drainage device. During the early postoperative period after a repeat right penetrating keratoplasty with anterior synechiolysis, his right intraocular pressure was persistently raised. The AS-OCT was used to aid in the assessment of the patient.
  
  
  RESULTS
  The AS-OCT showed obstruction of the glaucoma drainage device by iris tissue and enabled precise placement of the iridectomy immediately overlying the tube orifice.
  
  
  CONCLUSIONS
  The AS-OCT is a useful investigative tool that enables a better evaluation of the structures within the AS. The noncontact nature of the AS-OCT also makes it suitable in postpenetrating keratoplasty eyes where undue pressure on the corneal graft should be avoided.
authors.affiliation: Cornea and External Disease Service, Singapore National Eye Centre, Singapore. jocelynchua77@yahoo.com
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Chua
authors.forename: Jodhbir S
authors.initials: JS
authors.lastname: Mehta
authors.forename: Donald T H
authors.initials: DT
authors.lastname: Tan
mesh_terms: D000869:Anterior Eye Segment / Q000473:pathology*; D004868:Equipment Failure; D005901:Glaucoma / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D020327:Glaucoma Drainage Implants / Q000009:adverse effects; D006801:Humans; D007429:Intraocular Pressure; D032801:Iridectomy; D007498:Iris / Q000473:pathology; D007640:Keratoconus / Q000601:surgery; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012086:Reoperation; D041623:Tomography, Optical Coherence