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A new algorithm for automated nystagmus acuity function analysis
  1. Zheng Tai1,2,
  2. Richard W Hertle1,
  3. Richard A Bilonick1,
  4. Dongsheng Yang1
  1. 1The Laboratory of Visual and Ocular Motor Neurophysiology, The UPMC and Children's Eye Center, Department of Ophthalmology, Pediatric Ophthalmology, The Children's Hospital of Pittsburgh and University of Pittsburgh, Pittsburgh, Pennsylvania, USA
  2. 2Southwest Eye Hospital, Southwest Hospital, Third Military Medical University, Chongqing, China
  1. Correspondence to Dr Dongsheng Yang, The Ocular Motor Neurophysiology Laboratory, The UPMC Eye Center, Department of Ophthalmology, Pediatric Division, The Children's Hospital of Pittsburgh of UPMC and University of Pittsburgh, 3rd Floor, Room 3649, One Children Drive, 4401 Penn Avenue, Pittsburgh, Pennsylvania 15201, USA; yangd{at}


Aims We developed a new data analysis algorithm called the automated nystagmus acuity function (ANAF) to automatically assess nystagmus acuity function. We compared results from the ANAF with those of the well-known expanded nystagmus acuity function (NAFX).

Methods Using the ANAF and NAFX, we analysed 60 segments of nystagmus data collected with a video-based eye tracking system (EyeLink 1000) from 30 patients with infantile or mal-development fusional nystagmus. The ANAF algorithm used the best-foveation positions (not true foveation positions) and all data points in each nystagmus cycle to calculate a nystagmus acuity function.

Results The ANAF automatically produced a nystagmus acuity function in a few seconds because manual identification of foveation eye positions is not required. A structural equation model was used to compare the ANAF and NAFX. Both ANAF and NAFX have similar measurement imprecision and relatively little bias. The estimated bias was not statistically significant for either methods or replicates.

Conclusions We conclude that the ANAF is a valid and efficient algorithm for determining a nystagmus acuity function.

  • Nystagmus
  • eye movement disorders
  • visual acuity
  • muscles
  • vision
  • diagnostic tests/investigation

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  • Funding This project has been partly supported by the Competitive Medical Research Fund (CMRF) from the University of Pittsburgh and by the Department of Ophthalmology, University of Pittsburgh.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval This study was conducted with the approval of the Institutional Review Board of the University of Pittsburgh.

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

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