title: [Quantitative observation on changes of anterior segment by ultrasound biomicroscopy after posterior chamber phakic intraocular lens implantation].
abstract: OBJECTIVE
  The objective is to study the safety and effectiveness of implantation of posterior chamber phakic intraocular contact lens (ICL) by observing the changes in anterior segment using ultrasound biomicroscopy (UBM).
  
  
  METHODS
  It was a perspective study. The study sampled 30 high myopia patients (30 eyes) who were treated with posterior chamber phakic ICL implant. Central anterior chamber depth (ACD), trabecular-iris angle (TIA), angle opening distance (AOD500), trabecular-ciliary processes distance (TCPD) and iris-ciliary processes distance (ICPD) were measured using UBM preoperatively, 3 months and 1 year postoperatively. The distance from ICL to the central surface of lens and peripheral lens and intra-ocular pressure were measured postoperatively and examined using slit-lamp biomicroscope. One-way ANOVA was used to analyze the distance between peripheral surface of ICL and the lens. One-way repeated measures ANOVA and Bonferroni were conducted.
  
  
  RESULTS
  Preoperatively, 3 months and 1 year postoperatively, ACD were (3.16±0.08) mm, (2.76±0.13) mm, (2.74±0.14) mm; AOD500 were (0.45±0.04) mm, (0.41±0.04) mm, (0.41±0.03) mm; TIA were (35.00±3.24)°, (32.47±3.56)°, (32.40±3.23)°, respectively. There were significant difference in TIA, ACD and AOD (P<0.05) between preoperative and postoperative data. There was no significant difference between the two postoperative periods tested. TCPD and ICPD showed no significant difference between various time points (F=0.49, F=0.57; P>0.05).
  
  
  CONCLUSIONS
  The decrease in ACD depth and correction in TIA and AOD were the noticeable changes observed in morphological structure of the ocular anterior segment after the ICL treatment. The incidence of complication did not increase as the result of the minor changes in morph structure during the course of the study. However, the long-term effects would require further long-term observation.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China.
authors.forename: Rui-na
authors.initials: RN
authors.lastname: Wang
authors.forename: Guang-ying
authors.initials: GY
authors.lastname: Zheng
authors.forename: Song-tian
authors.initials: ST
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Zhao
authors.forename: Hong-liang
authors.initials: HL
authors.lastname: Guo
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D033401:Microscopy, Acoustic; D009216:Myopia / Q000000981:diagnostic imaging* / Q000601:surgery; D011446:Prospective Studies; D055815:Young Adult