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Repeatability and agreement of ocular biometry measurements: Aladdin versus Lenstar
  1. Colm McAlinden1,2,3,
  2. Rongrong Gao1,4,
  3. Ayong Yu1,4,
  4. Xiaorui Wang1,
  5. Jing Yang1,
  6. Ye Yu1,4,
  7. Hao Chen1,4,
  8. Qinmei Wang1,4,
  9. Jinhai Huang1,4
  1. 1 School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
  2. 2 ABM University Health Board, Swansea, UK
  3. 3 Flinders University, Adelaide, South Australia, Australia
  4. 4 Key Laboratory of Vision Science, Ministry of Health of the People's Republic of China, Wenzhou, Zhejiang, China
  1. Correspondence to Dr Qinmei Wang, Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, Zhejiang 325027, China; wqm6{at}; and Dr Jinhai Huang; vip999vip{at}


Objective To assess the repeatability and agreement between the Aladdin and Lenstar biometers.

Methods Three consecutive measurements of the right eye of 102 subjects were acquired by the Aladdin (V.1.1.3) and the Lenstar (V.1.0.3), respectively, with a random order of which biometer to use first. Parameters compared included axial length (AL), anterior chamber depth (ACD), flat keratometry (Kf), steep keratometry (Ks), mean keratometry (Km), J0, J45 and white-to-white (WTW) distance. Intraocular lens (IOL) power formulas included SRK/T (Sanders-Retzlaff-Kraff/Theoretical), Holladay 1, Hoffer Q and Haigis. Repeatability (Sr), repeatability limit (r) and Bland-Altman limits of agreement (LoA) were calculated.

Results Sr was marginally better with the Lenstar for AL (0.02 mm), ACD (0.02 mm) and WTW distance (0.07 mm), but Sr was marginally better with the Aladdin for Kf (0.10 dioptre (D)), J0 (0.07 D) and J45 (0.06 D). In terms of agreement, the mean difference was small and non-statistically significant between the two devices for ACD, Ks and J45. The mean difference for Kf, Km, J0 and WTW distance were all statistically significantly lower with the Aladdin than the Lenstar for the exception of WTW distance. The Bland-Altman LoA displayed narrow ranges implying good agreement with the exception for WTW distance. For IOL formulas, the mean difference was very small and not statistically significantly different. The LoA were narrow (within 0.50 D), implying acceptable use of each device interchangeably.

Conclusions High levels of repeatability and agreement were found between the Aladdin and Lenstar suggesting that the devices may be used interchangeably in normal eyes with refractive error.

  • Imaging
  • Anterior chamber

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  • CM and RG contributed equally.

  • Contributors CM, RG, QW and JH: study conception and design. XRW and JY: performed the experiments. AY, YY and HC: analysed and interpreted the data. CM, RG, QW and JH: wrote the paper. CM, AY, YY, QW and JH: revised the paper. CM, RG, AY, XRW, JY, YY, HC, QW and JH: read and approved the final manuscript.

  • Funding Supported in part by the National Natural Science Foundation of China (81300807); the National Key Research and Development Programme of China (2016YFC0100200, 2016YFC0100201); Foundation of Wenzhou City Science & Technology Bureau (J20140014, Y20150076); Medical and Health Science and Technology Program of Zhejiang Province (2016RCB013); Zhejiang Provincial & Ministry of Health Research Fund For Medical Sciences (WKJ-ZJ-1530).

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval The study was adhered to the tenets of the Declaration of Helsinki for the use of human participants in biomedical research and approved by the Research Ethics Committee at Eye Hospital of Wenzhou Medical University.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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