title: Effects of scleral encircling surgery on vitreous cavity length and diopter.
abstract: OBJECTIVE
  To observe the changes of vitreous cavity length and diopter after scleral encircling (SE) produce.
  
  
  METHODS
  This prospective study included 68 eyes of 68 non-consecutive patients with macula-off retinal detachment who were operated by SE surgery. The corneal refractive power, ocular axial length and diopter were measured by keratometer, A-mode ultrasonic meter and computed dioptometer.
  
  
  RESULTS
  There was no significant difference in corneal refractive power among preoperative and postoperative 1, 3 and 6 mo (0.57±0.54 D at pre-surgery;0.72±0.26 D at 1mo; 0.71±0.34 D at 3mo; 0.69±0.31 D at 6mo; all P>0.05 ). Axial lengths were obviously lengthened, especially in vitreous cavity length (17.87±3.09 mm, 19.69±3.12 mm, 18.97±3.56 mm, 18.76±3.47 mm, 18.68±3.42 mm at pre-surgery, 1wk, 1, 3 and 6mo postoperatively, P <0.05) and diopter also increased at beginning and then recovered gradually. After 1 and 3 mo, axial length (vitreous cavity length) and myopia were more and in higher degree than before surgery.
  
  
  CONCLUSIONS
  The change of postoperative vitreous cavity length is the main factor that results in the changes of axial length and then makes the change of diopter.
authors.affiliation: Department of Ophthalmology, Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, Anhui Province, China.
authors.forename: Zi-Cheng
authors.initials: ZC
authors.lastname: Zhu
authors.affiliation: Department of Ophthalmology, Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, Anhui Province, China.
authors.forename: Gen-Jie
authors.initials: GJ
authors.lastname: Ke
authors.affiliation: Department of Ophthalmology, Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, Anhui Province, China.
authors.forename: Yue-Chun
authors.initials: YC
authors.lastname: Wen
authors.affiliation: Department of Ophthalmology, Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, Anhui Province, China.
authors.forename: Zhang-You
authors.initials: ZY
authors.lastname: Wu
keywords: axial length; diopter; sclera encircling; vitreous cavity length