title: [Intraocular lens power calculation after corneal refractive surgery].
abstract: OBJECTIVE
  To investigate the effective method for the calculation of intraocular lens power retrospectively from post-LASIK cases.
  
  
  METHODS
  It was a retrospective case series. 40 eyes of 28 patients (14 male and 14 Female) had the Phacoemulsification post-LASIK in HongKong Sanitorium & Hospital; the age ranged from 41.00 to 69.00 years ages, (50.68 +/- 6.56) years. LASIK was done from January, 1997 to April, 2005. Phacoemulsification was done from October, 2000 to September, 2005.
  
  
  RESULTS
  Average axial length was (28.06 +/- 1.98) mm (rang from 24.28 to 31.96 mm). The initial refraction power (Spherical Equivalent, SE) before LASIK was from -3.13 to -18.00 D, (-10.44 +/- 3.93) D. K value pre-LASIK was 41.40 to 46.90 D, (43.57 +/- 1.47) D. The best corrected visual acuity (BCVA) preLASIK was 20/20 in 19 eyes, 20/25 in 10 eyes, 20/30 in 7 eyes and 20/40 in 4 eyes. The refraction power of 6 months post-LASIK (SE) was -2.83 to +1.25 D, (-0.32 +/- 0.95) D. The refraction power pre-phaco (SE) was -5.75 to +1.13 D, (-2.35 +/- 2.16) D. The calculated K1 (KpreLASIK-RpostLASIK + RpreLASIK) was 27.60 to 40.70 D, (34.62 +/- 3.56) D. The K from the IOLmaster (K2) was 32.39 to 43.53 D, (38.04 +/- 2.45) D. The target refraction of K1 was -3.69 to 0.61 D, (-1.32 +/- 1.00) D, the target refraction of K2 was -3.67 approximately 3.95 D, (-0.60 +/- 1.84) D. There was significant difference between these two target refraction, (t = -2.40, P = 0.02). The refraction power of post-phaco (> 3 months) was -4.50 to +1.75 D, (-1.10 +/- 1.51) D. The BCVA post-Phaco was 20/20 in 20 eyes, 20/25 in 9 eyes, 20/30 in 5 eyes and 20/40 in 6 eyes.
  
  
  CONCLUSIONS
  The formula used in the study for the calculation of intraocular lens power is accurate and effective.
authors.affiliation: Department of Ophthalmology, Beijing Hospital, Beijing 100730, China. yonglilv@gmail.com
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Dai
authors.forename: Yao-zhen
authors.initials: YZ
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.forename: Tong
authors.initials: T
authors.lastname: Wu
authors.forename: Wei-da
authors.initials: WD
authors.lastname: Li
authors.forename: Shu-ming
authors.initials: SM
authors.lastname: Zhang
authors.forename: Shao-ping
authors.initials: SP
authors.lastname: Xu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.forename: Dao-xin
authors.initials: DX
authors.lastname: Xie
authors.forename: Jia-hao
authors.initials: JH
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D011184:Postoperative Period; D012029:Refraction, Ocular; D012189:Retrospective Studies