title: Exposure rate of hydroxyapatite orbital implants a 15-year experience of 802 cases.
abstract: OBJECTIVE
  To document the long-term experience with hydroxyapatite (HA) orbital implants (Bio-Eye) and analyze the factors influencing implant exposure, including surgical type, procedural modification, use of different wrapping materials and peg materials.
  
  
  METHODS
  Retrospective observational case series.
  
  
  METHODS
  Eight hundred two eyes from 802 patients who underwent anophthalmic socket surgery (eviscerations, enucleations, secondary implant placements) using HA implants, performed by one surgeon between May 1990 and December 2005.
  
  
  METHODS
  All patients' clinical records were reviewed. Baseline age, cause of anophthalmic surgery, surgical type, size of HA implant, wrapping material, and peg system were recorded.
  
  
  METHODS
  Postoperative complications, especially implant exposure, were recorded separately before and after pegging, and compared according to type of surgery, wrapping material, and peg system.
  
  
  RESULTS
  The main cause of anophthalmic surgery was trauma (73%). A variety of wrapping materials have been used, including Tutoplast-dura, Vicryl mesh, autogenous sclera, and polyester-urethane. Implant exposure occurred in 17 patients (2.1%) before pegging and 14 (4.0%) after pegging. The exposure rate was significantly higher in eyes eviscerated without (7.2%) than with (1.1%) keratectomy (P = 0.018), but did not differ according to type of surgery (P = 0.710). When distributed according to 5-year periods, the exposure rate was higher from 1990 to 1994 (4.7%) than in later periods (P = 0.004). In patients who underwent enucleation or secondary implantation, there was no difference in exposure rate between Tutoplast-dura- and Vicryl mesh-wrapped implants (P = 0.235). Among the 353 patients (44.0%) who underwent pegging, those who received titanium-pegged implants had a significantly lower incidence of peg extrusion (5.2%), major discharge (5.2%), and pyogenic granuloma (9.1%) than those with nonsleeved polymethyl methacrylate and sleeved polycarbonate peg materials (P<0.05).
  
  
  CONCLUSIONS
  Exposures associated with HA orbital implants decreased with the improvement of surgical technique over time and have been managed successfully, both before and after pegging. The incidence of peg-related complications have decreased since the introduction of the titanium peg system.
authors.affiliation: Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Yoon
authors.forename: Helen
authors.initials: H
authors.lastname: Lew
authors.forename: Sung Joo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Sang Yeul
authors.initials: SY
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000853:Anophthalmos / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D015353:Eye Enucleation; D017234:Eye Evisceration; D005137:Eye, Artificial; D005260:Female; D005548:Foreign-Body Migration / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D020273:Orbital Implants; D011183:Postoperative Complications; D012189:Retrospective Studies; D012307:Risk Factors; D013529:Surgical Wound Dehiscence / Q000453:epidemiology*
chemical_list: D020099:Coated Materials, Biocompatible; D017886:Durapatite