title: The effect of cycloplegia on the lenstar and the IOLMaster biometry.
abstract: OBJECTIVE
  To evaluate the effect of cycloplegia on ocular biometry measurements and intraocular lens (IOL) power calculation using the Lenstar LS900 (Haag-Streit AG, Koeniz, Switzerland) and the IOLMaster (Carl Zeiss Meditec AG, Jena, Germany) biometers and to assess the agreement between the devices.
  
  
  METHODS
  Measurements were taken with the Lenstar and the IOLMaster on 43 healthy volunteers with a mean age of 22.1 ± 4.7 years (range, 18 to 37 years). Axial length (AL), anterior chamber depth (ACD), corneal curvature, and horizontal iris width (white-to-white [WTW]) measurements were performed with and without cycloplegia. The IOL powers were calculated using four formulas: Sanders-Retzlaff-Kraff/Theoretical, Holladay 1, Hoffer Q, and Haigis.
  
  
  RESULTS
  Cycloplegia had no significant effect on AL or corneal curvature. However, ACD and WTW significantly increased postcycloplegia (Lenstar, 0.09 ± 0.06 mm and 0.10 ± 0.17 mm, respectively; IOLMaster, 0.06 ± 0.07 mm and 0.43 ± 0.35 mm, respectively; p <0.001). The Lenstar AL measurements were statistically but not clinically significantly longer than those of the IOLMaster (precycloplegia, 0.03 ± 0.03 mm; postcycloplegia, 0.02 ± 0.03 mm; p < 0.001). For ACD measurements, the 95% limits of agreement were -0.19 to 0.20 mm without cycloplegia and -0.11 to 0.17 mm with cycloplegia. The 95% limits of agreement for WTW measurements were -1.07 to 0.45 mm with cycloplegia. The only significantly different IOL power precycloplegia and postcycloplegia was with the Haigis formula and the Lenstar measurements: 15.12 ± 3.87 diopters and 15.26 ± 3.92 diopters (p < 0.01).
  
  
  CONCLUSIONS
  Cycloplegia affected ACD and WTW but not AL or corneal curvature measurements. Generally, good agreement was found between the Lenstar and the IOLMaster, although not for WTW. Differences between these devices do not produce a clinically significant impact on IOL power.
authors.affiliation: School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Huang
authors.forename: Colm
authors.initials: C
authors.lastname: McAlinden
authors.forename: Binbin
authors.initials: B
authors.lastname: Su
authors.forename: Konrad
authors.initials: K
authors.lastname: Pesudovs
authors.forename: Yifan
authors.initials: Y
authors.lastname: Feng
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Hua
authors.forename: Feng
authors.initials: F
authors.lastname: Yang
authors.forename: Chao
authors.initials: C
authors.lastname: Pan
authors.forename: Huyong
authors.initials: H
authors.lastname: Zhou
authors.forename: Qinmei
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000867:Anterior Chamber / Q000033:anatomy & histology* / Q000187:drug effects; D001699:Biometry / Q000295:instrumentation*; D003315:Cornea / Q000033:anatomy & histology* / Q000187:drug effects; D005260:Female; D006801:Humans; D007368:Interferometry; D007908:Lens, Crystalline / Q000033:anatomy & histology* / Q000187:drug effects; D008297:Male; D009184:Mydriatics / Q000494:pharmacology*; D012372:ROC Curve; D012029:Refraction, Ocular; D055815:Young Adult
chemical_list: D009184:Mydriatics