title: Prophylactic removal and microbiological evaluation of calcified plaques after pterygium surgery.
abstract: OBJECTIVE
  The aim of this study was to investigate microbiological characteristics of prophylactically removed calcified plaques developed after pterygium excision, and to evaluate risk factors for the growth of microorganisms.
  
  
  METHODS
  Only exposed calcified plaques developed at the same site of previous pterygium excision were prospectively removed in 15 eyes of 14 patients. Plaques were completely removed, divided into small pieces and evaluated for microbiological identification. Underlying scleral defects were reconstructed using a conjunctival autograft, amniotic membranes and scleral patch grafts according to the size and depth of the defects. Based on the results of microbiologic cultures, eyes were divided into two groups and risk factors for microbial growth were analyzed.
  
  
  RESULTS
  At surgery, the mean age of the patients was 71.2 ± 5.8 years and 71.4 % were females. The mean time interval between pterygium excision and calcified plaque removal was 19.3 ± 13.8 years. Six of 15 (40 %) removed plaques showed bacterial growth, and Stenotrophomonas maltophilia was the most frequently isolated microorganism. The size of calcified plaques was the only risk factor for culture-positive results (p = 0.045). Underlying scleral defects were successfully repaired without any serious complication.
  
  
  CONCLUSIONS
  Microorganisms can be isolated from calcified plaques developed at the site of previous pterygium excision, and the size of plaques is the only risk factor for culture-positive results. To remove potential source of infection, prophylactic removal of calcified plaques and scleral surface reconstruction should be considered, especially when the plaques are exposed and large.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Tai Jun
authors.initials: TJ
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea. docchoi@hanmail.net.|Department of Ophthalmology, Seoul National University Hospital Healthcare System Gangnam Center, 39th FL., Gangnam Finance Center, 737 Yeoksam-dong, Gangnam-gu, Seoul, 135-984, Republic of Korea. docchoi@hanmail.net.|Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, Republic of Korea. docchoi@hanmail.net.
authors.forename: Hyuk Jin
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.|Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, Republic of Korea.
authors.forename: Mee Kum
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.|Laboratory of Ocular Regenerative Medicine and Immunology, Seoul Artificial Eye Center, Seoul National University Hospital Biomedical Research Institute, Seoul, Republic of Korea.
authors.forename: Won Ryang
authors.initials: WR
authors.lastname: Wee
mesh_terms: D000368:Aged; D001419:Bacteria / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D002114:Calcinosis / Q000382:microbiology* / Q000601:surgery; D003229:Conjunctival Diseases / Q000382:microbiology* / Q000601:surgery; D015818:Eye Infections, Bacterial / Q000382:microbiology* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011183:Postoperative Complications; D011446:Prospective Studies; D011625:Pterygium / Q000601:surgery*; D012307:Risk Factors; D015422:Scleral Diseases / Q000382:microbiology* / Q000601:surgery
keywords: Calcified plaque; Microorganism; Pterygium; Stenotrophomonas maltophilia