title: The effect of pupil dilation on AL-Scan biometric parameters.
abstract: The purpose of this study was to investigate the effects of pupil dilation on the parameters of the AL-Scan (Nidek Co., Ltd, Gamagori, Japan). We compared the measurements of axial length (AL), anterior chamber depth (ACD), central corneal keratometry reading, pupil diameter, and intraocular lens (IOL) power of 72 eyes of 72 healthy volunteers and patients scheduled for cataract surgery before and 45 min after instillation of cyclopentolate hydrochloride 1 % using the AL-Scan. Intraobserver repeatability was assessed by taking three consecutive recordings of ACD and AL. Only ACD readings were significantly different between predilation and postdilation (P < 0.001). The difference of the other measurements between two sessions was not statistically significant (P > 0.001). Only two cases in the study demonstrated changes in IOL power higher than 0.5 D. The intraobserver repeatability of both devices was good (CV values for ACD and AL were 0.16 and 0.20 %, respectively). Dilated pupil size did not affect the measurement of IOL power using the A-Scan optical biometer, but increase in ACD after dilation should be taken into account when performing refractive surgeries in which ACD is very important such as phakic anterior chamber IOL implantation.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ondokuz Mayıs University, 55139, Samsun, Turkey. canertugrul73@hotmail.com.
authors.forename: Ertuğrul
authors.initials: E
authors.lastname: Can
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ondokuz Mayıs University, 55139, Samsun, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Duran
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ondokuz Mayıs University, 55139, Samsun, Turkey.
authors.forename: Tuğba
authors.initials: T
authors.lastname: Çetinkaya
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ondokuz Mayıs University, 55139, Samsun, Turkey.
authors.forename: Nurşen
authors.initials: N
authors.lastname: Arıtürk
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000502:physiology; D058452:Axial Length, Eye / Q000187:drug effects / Q000502:physiology; D001699:Biometry; D002386:Cataract / Q000503:physiopathology*; D003315:Cornea / Q000502:physiology; D003519:Cyclopentolate / Q000494:pharmacology; D005260:Female; D006801:Humans; D007564:Japan; D007908:Lens, Crystalline / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000494:pharmacology; D011680:Pupil / Q000187:drug effects / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D009184:Mydriatics; D003519:Cyclopentolate
keywords: AL-Scan; Anterior chamber depth; Axial length; Optical biometry