title: Effect of pupil size on biometry measurements using the IOLMaster.
abstract: OBJECTIVE
  To evaluate the effect of pupil dilation on biometric measurements and intraocular lens power calculation using the IOLMaster (Carl Zeiss Meditec).
  
  
  METHODS
  Prospective, observational case series.
  
  
  METHODS
  In this prospective study, 2 consecutive optical biometry measurements, before and after pupil dilation, were obtained using the IOLMaster on 318 eyes of 214 patients at the cataract presurgery clinic. The parameters compared were axial length, corneal power, cylinder, and the corresponding intraocular lens power, which was calculated using the Sanders-Retzlaff-Kraff/Theoretical formula.
  
  
  RESULTS
  This study found no statistically significant difference before and after dilation in axial length (0.005 mm; P = .476), corneal power (0.001 diopters [D]; P = .933), or calculated intraocular lens power (0.011 D; P = .609). A statistically significant difference was shown in cylinder measurements before and after dilation (0.102 D; P < .001).
  
  
  CONCLUSIONS
  This study demonstrated there is no clinically significant effect of pupil dilation on the IOLMaster measurements of axial length, corneal power, and corresponding theoretical intraocular lens power calculated using the Sanders-Retzlaff-Kraff/Theoretical formula.
authors: Hebrew University Hadassah Medical School, Jerusalem Israel. Electronic address: galiadler@gmail.com.
authors: Galia
authors: G
authors: Adler
authors: Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Jonathan
authors: J
authors: Shahar
authors: Department of Radiology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Rivka
authors: R
authors: Kesner
authors: Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Eldar
authors: E
authors: Rosenfeld
authors: Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Naomi
authors: N
authors: Fischer
authors: Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Anat
authors: A
authors: Loewenstein
authors: Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
authors: Shimon
authors: S
authors: Kurtz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058452:Axial Length, Eye / Q000473:pathology*; D001699:Biometry / Q000379:methods*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007368:Interferometry; D007910:Lenses, Intraocular; D008027:Light; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D055095:Optics and Photonics; D010656:Phenylephrine / Q000008:administration & dosage; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects / Q000502:physiology*; D014331:Tropicamide / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D004338:Drug Combinations; D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine; D014331:Tropicamide