Article Text

Download PDFPDF
Original article
Screening for amblyopia risk factors in pre-verbal children using the Plusoptix photoscreener: a cross-sectional population-based study
  1. Ali Akbar Saber Moghaddam1,
  2. Abbas Kargozar1,
  3. Mehran Zarei-Ghanavati1,
  4. Marzieh Najjaran2,
  5. Vahideh Nozari2,
  6. Mohammad Taghi Shakeri3
  1. 1Eye Research Center of the Mashhad University of Medical Sciences, Khatam-al-Anbia Eye Hospital, Mashhad, Iran
  2. 2Khatam-al-Anbia Eye Hospital, The Mashhad University of Medical Sciences, Mashhad, Iran
  3. 3The Mashhad University of Medical Sciences, Mashhad, Iran
  1. Correspondence to Mehran Zarei-Ghanavati, Mashhad University of Medical Sciences (MUMS), Eye Research Center and Department of Ophthalmology, Khatam-al-Anbia Eye Center, Abotaleb Blvd., Mashhad, Iran; mehran_zarei{at}


Aims To evaluate the accuracy and applicability of Plusoptix photoscreener in screening pre-verbal children at risk of amblyopia.

Methods In this cross-sectional population-based study 996 children aged 6–36 months were screened with the Plusoptix. The children underwent complete examinations that included a manual cycloplegic retinoscopy, slit lamp examination, cover test, the Hirschberg test and an assessment of fixation pattern. In addition, the prevalence of amblyogenic risk factors was estimated, the Plusopix measurements were compared with cycloplegic retinoscopy, and the referral criteria were modified to improve the accuracy of the device.

Results Amblyogenic hyperopia >+3.50 D, myopia >−3.00 D, astigmatism >1.50 D in the orthogonal meridian or >1.00 D in the oblique meridian, or anisometropia >1.50 D was detected in 4.7%, 0.0%, 12.3% and 0.5% of the samples, respectively. The average difference between retinoscopy and photorefraction for spherical equivalence was −0.16±1.0 D (p<0.05). Testability was 98.1% for the Plusoptix. The Plusoptix vision screener referred 47.8% of these children for sensitivity, specificity, positive predictive value and false-negative rates of 100%, 38.7%, 19% and 100%, respectively. These same measurements with the modified referral criteria (hyperopia ≥2.00 D in children under 12 months and astigmatism ≥1.25 D) were 93.6%, 51.2%, 21.7% and 98.2%.

Conclusion The Plusoptix is a useful objective screening instrument, but still has low specificity for detecting amblyopia risk factors in the paediatric population.

  • Plusoptix
  • photoscreener
  • retinoscopy
  • amblyopia
  • Mashhad
  • vision
  • public health
  • diagnostic tests/investigation
  • child health (paediatrics)

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Funding The study was funded by Mashhad University of Medical Sciences and Welfare Organization of Khorasan Razavi.

  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval This study was conducted with the approval of the Mashhad University of Medical Sciences.

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

Linked Articles

  • At a glance
    Harminder S Dua Arun D Singh