Use of log-scaled crowded visual acuity charts in clinical studies regarding amblyopia
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Abstract
Purpose
Log-scaled crowded charts using standardized testing protocol are essential for precise and reproducible visual acuity (VA) testing regarding amblyopia. Despite common acceptance of these standards, current VA testing clinical practice shows considerable diversity. The purpose of this retrospective literature review was to investigate the methodology of VA measurement and reporting in pediatric ophthalmology literature regarding amblyopia.
Methods
We searched PubMed for clinical trials regarding amblyopia, published from January 1994 to July 2016. Primary outcomes included VA measurement methodology, namely use of (a) log-scaled chart, (b) crowded chart, and (c) specified testing protocol. The study design, publication year, and the journal’s impact factor were analyzed in relation to the primary outcomes.
Results
Out of the 165 initial reports, 150 were included. VA was measured with a log-scaled chart in 65%, with a crowded chart in 57%, and with a specified protocol in 51% of studies. All three criteria were met in 43% of studies and in multivariable logistic model, they were associated with more recent publication year (odds ratio [OR] = 1.11, 95% confidence interval [95%CI] = 1.03–1.20) and were more likely to be present in higher impact factor journals (OR = 1.42, 95%CI = 1.17–1.72) or randomized controlled trials (OR = 3.09, 95%CI = 1.44–6.59).
Conclusions
In the last two decades, more than half of clinical trials addressing amblyopia have not followed the recommended methodology for optimal visual acuity assessment. Thus, their measurements may have been contaminated with noise, and their respective results and conclusions may include errors. Adhering to optimal, standardized methodology is key to progress in both clinical and research grounds.
Keywords
Visual acuity logMAR Crowded Standardized protocolNotes
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
References
- 1.Bailey I, Lovie J (1976) New design principles for visual acuity letter charts. Am J Optom Physiol Optic 53:740–745CrossRefGoogle Scholar
- 2.Lovie–Kitchin J (1988) Validity and reliability of visual acuity. Ophthal Physiol Opt 8:363–370CrossRefGoogle Scholar
- 3.Elliott D (2016) The good (logMAR), the bad (Snellen) and the ugly (BCVA, number of letters read) of visual acuity measurement. Ophthalmic Physiol Opt 36:355–358. https://doi.org/10.1111/opo.12310 CrossRefGoogle Scholar
- 4.Hartmann E, Dobson V, Hainline L et al (2001) Preschool vision screening: summary of a task force report. Ophthalmology 108:479–486CrossRefGoogle Scholar
- 5.Lovie-Kitchin J (2015) Is it time to confine Snellen charts to the annals of history? Ophthalmic Physiol Opt 35:631–636. https://doi.org/10.1111/opo.12252 CrossRefGoogle Scholar
- 6.McGraw P, Winn B, Gray L, Elliott D (2000) Improving the reliability of visual acuity measures in young children. Ophthal Physiol Opt 20:173–184CrossRefGoogle Scholar
- 7.Stewart C (2000) Comparison of Snellen and log-based acuity scores for school aged children. Br Orthopt J 57:32–38Google Scholar
- 8.Fern K, Manny R, Davis J, Gibson R (1986) Contour interaction in the preschool child. Am J Optom Physiol Optic 63:313–318CrossRefGoogle Scholar
- 9.Rydberg A, Ericson B, Lennerstrand G et al (1999) Assessment of visual acuity in children aged 1 1/2-6 years, with normal and subnormal vision. Strabismus 7:1–24CrossRefGoogle Scholar
- 10.Elliott M, Firth A (2009) The logMAR Kay picture test and the logMAR acuity test: a comparative study. Eye(Lond) 23:85–88. https://doi.org/10.1038/sj.eye.6702990 Google Scholar
- 11.Hessa RF, Jacobsa RJ (1979) A preliminary report of acuity and contour interactions across the amblyope’s visual field. Vis Res 19:1403–1408CrossRefGoogle Scholar
- 12.Blackhurst D, Maguire M (1989) Reproducibility of refraction and visual acuity measurement under a standard protocol. The Macular Photocoagulation Study Group. Retina 9:163–169Google Scholar
- 13.Bailey I, Lovie-Kitchin J (2013) Visual acuity testing. From the laboratory to the clinic. Vis Res 90:2–9. https://doi.org/10.1016/j.visres.2013.05.004 CrossRefGoogle Scholar
- 14.Birch E, Strauber S, Beck R, Holmes J (2009) Comparison of the amblyopia treatment study HOTV and the electronic-early treatment of diabetic retinopathy study visual acuity protocols in amblyopic children aged 5 to 11 years. JAAPOS 13:75–78. https://doi.org/10.1016/j.jaapos.2008.07.007
- 15.Wilson M (2009) The art and science of examining a child. In: Wilson M, Trivedi R, Saunders R (eds) Pediatric ophthalmology: current thought and a practical guide. Springer Berlin Heidelberg, Berlin Heidelberg, pp 1–6Google Scholar
- 16.Holmes J, Beck R, Repka M et al (2001) The amblyopia treatment study visual acuity testing protocol. Arch Ophthalmol 119:1345–1353CrossRefGoogle Scholar
- 17.Williams M, Moutray T, Jackson A (2008) Uniformity of visual acuity measures in published studies. Invest Ophthalmol Vis Sci 49:4321–4327. https://doi.org/10.1167/iovs.07-0511 CrossRefGoogle Scholar
- 18.Tsou B, Bressler N (2017) Visual acuity reporting in clinical research publications. JAMA Ophthalmol 135:651–653. https://doi.org/10.1001/jamaophthalmol.2017.0932 CrossRefGoogle Scholar
- 19.Maldonado G, Greenland S (1993) Simulation study of confounder-selection strategies. Am J Epidemiol 138:923–936CrossRefGoogle Scholar
- 20.Pediatric Eye Disease Investigator Group, Repka M, Kraker R et al (2015) A randomized trial of levodopa as treatment for residual amblyopia in older children. Ophthalmology 122:874–881. https://doi.org/10.1016/j.ophtha.2015.01.002 CrossRefGoogle Scholar
- 21.Paudel P, Ramson P, Naduvilath T et al (2014) Prevalence of vision impairment and refractive error in school children in Ba Ria - Vung Tau province, Vietnam. Clin Exp Ophthalmol 42:217–226. https://doi.org/10.1111/ceo.12273 CrossRefGoogle Scholar
- 22.Li R, Ngo C, Nguyen J, Levi D (2011) Video-game play induces plasticity in the visual system of adults with amblyopia. PLoS Biol 9:e1001135. https://doi.org/10.1371/journal.pbio.1001135 CrossRefGoogle Scholar
- 23.Koklanis K, Le T, Georgievski Z (2010) The base-to-base induced-tropia prism test for detection of amblyopia: a pilot study. J AAPOS 14:484–487. https://doi.org/10.1016/j.jaapos.2010.08.015 CrossRefGoogle Scholar
- 24.Holladay J (2004) Visual acuity measurements. J Cataract Refract Surg 30:287–290. https://doi.org/10.1016/j.jcrs.2004.01.014 CrossRefGoogle Scholar
- 25.Schulze-Bonsel K1, Feltgen N, Burau H, Hansen L, Bach M (2006) Visual acuities “hand motion” and “counting fingers” can be quantified with the freiburg visual acuity test. Invest Ophthalmol Vis Sci 47(3):1236–1240CrossRefGoogle Scholar