Documenta Ophthalmologica

, Volume 124, Issue 2, pp 99–107 | Cite as

Reliability of acuities determined with the sweep visual evoked potential (sVEP)

  • William H. RidderIII
  • Anna Tong
  • Theresa Floresca
Original Research Article


sVEPs are generally used to rapidly obtain visual acuity. Several studies have determined the reliability of acuity measurements with psychophysical techniques. The aim of this study was to determine the intersession and intrasession variabilities of sVEP measurements. Twenty-four normal, adult subjects took part in this project. Stimulus production and data analyses were done using an Enfant 4010. Standard VEP recording techniques were employed. Data were collected on two separate days (at least 1 week apart). At each visit, two complete sets of sVEP data were collected and averaged. A logMAR acuity chart was also used to determine the acuity at each visit. Paired t tests, 95% confidence intervals, intraclass correlation coefficients, and coefficients of repeatability were used to determine whether there was a difference in the intrasession and intersession acuities. The mean acuity difference and coefficient of repeatability were +0.01 and 0.191 for visit 1 and −0.019 and 0.186 for visit 2, respectively. The mean acuity difference and coefficient of repeatability across visits were +0.008 and 0.176 for the first acuity and−0.02 and 0.170 for the second acuity, respectively. Paired t tests did not find a significant difference between any set of data or the average for visits one and two (all P values > 0.05). The intraclass correlation coefficients comparing the average sVEP data and the logMAR data for visits 1 and 2 were 0.71 and 0.88, respectively. The coefficients of repeatability for the averaged sVEP acuity and the logMAR acuity for the two visits were 0.11 and 0.07, respectively. The repeatability of the sVEP acuity estimate in a large population of adults is similar to that of previous published reports on infants and is nearly as high as that of logMAR acuity chart data. The repeatability is the same for single best estimates of acuity and averaged estimates of acuity across visits.


Visual acuity Sweep visual evoked potential logMAR acuity 


Conflict of interest



  1. 1.
    Arditi A, Cagenello R (1993) On the statistical reliability of letter-chart visual acuity measurements. Invest Ophthalmol Vis Sci 34:120–129PubMedGoogle Scholar
  2. 2.
    Camparini M, Cassinari P, Ferrigno L, Macaluso C (2001) ETDRS-fast: implementing psychophysical adaptive methods to standardized visual acuity measurement with ETDRS charts. Invest Ophthalmol Vis Sci 42:1226–1231PubMedGoogle Scholar
  3. 3.
    Manny RE, Hussein M, Gwiazda J, Marsh-Tootle W (2003) Repeatability of ETDRS visual acuity in children. Invest Ophthalmol Vis Sci 44:3294–3300PubMedCrossRefGoogle Scholar
  4. 4.
    Kheterpal S, Jones HS, Auld R, Moseley MJ (1996) Reliability of visual acuity in children with reduced vision. Ophthalmic Physiol Opt 16:447–449PubMedCrossRefGoogle Scholar
  5. 5.
    Tyler CW, Apkarian P, Levi DM, Nakayama K (1979) Rapid assessment of visual function: an electronic sweep technique for the pattern visual evoked potential. Invest Ophthalmol Vis Sci 18:703–713PubMedGoogle Scholar
  6. 6.
    Norcia AM, Tyler CW (1985) Infant VEP acuity measurements: analysis of individual differences and measurement error. Electroencephalogr Clin Neurophysiol 61:359–369PubMedCrossRefGoogle Scholar
  7. 7.
    Prager TC, Zou YL, Jensen CL, Fraley JK, Anderson RE, Heird WC (1999) Evaluation of methods for assessing visual function of infants. J Aapos 3:275–282PubMedCrossRefGoogle Scholar
  8. 8.
    Hamer RD, Norcia AM, Tyler CW, Hsu-Winges C (1989) The development of monocular and binocular VEP acuity. Vis Res 29:397–408PubMedCrossRefGoogle Scholar
  9. 9.
    Lauritzen L, Jorgensen MH, Michaelsen KF (2004) Test-retest reliability of swept visual evoked potential measurements of infant visual acuity and contrast sensitivity. Pediatr Res 55:701–708PubMedCrossRefGoogle Scholar
  10. 10.
    Yadav NK, Almoqbel F, Head L, Irving EL, Leat SJ (2009) Threshold determination in sweep VEP and the effects of criterion. Doc Ophthalmol 119:109–121PubMedCrossRefGoogle Scholar
  11. 11.
    Ridder WH III, McCulloch D, Herbert AM (1998) Stimulus duration, neural adaptation, and sweep visual evoked potential acuity estimates. Invest Ophthalmol Vis Sci 39:2759–2768PubMedGoogle Scholar
  12. 12.
    Ridder WH III (2004) Methods of visual acuity determination with the spatial frequency sweep visual evoked potential. Doc Ophthalmol 109:239–247PubMedCrossRefGoogle Scholar
  13. 13.
    Ridder WH III, Rouse MW (2007) Predicting potential acuities in amblyopes : Predicting post-therapy acuity in amblyopes. Doc Ophthalmol 114:135–145PubMedCrossRefGoogle Scholar
  14. 14.
    Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1:307–310PubMedCrossRefGoogle Scholar
  15. 15.
    Holopigian K, Bach M (2010) A primer on common statistical errors in clinical ophthalmology. Doc Ophthalmol 121:215–222PubMedCrossRefGoogle Scholar
  16. 16.
    Rouse MW, Borsting E, Deland PN (2002) Reliability of binocular vision measurements used in the classification of convergence insufficiency. Optom Vis Sci 79:254–264PubMedCrossRefGoogle Scholar
  17. 17.
    Fleiss J (1986) The design and analysis of clinical experiments. Wiley, New YorkGoogle Scholar
  18. 18.
    Simon F, Rassow B (1986) Retinal visual acuity with pattern VEP normal subjects and reproducibility. Graefes Arch Clin Exp Ophthalmol 224:160–164Google Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • William H. RidderIII
    • 1
  • Anna Tong
    • 1
  • Theresa Floresca
    • 1
  1. 1.Southern California College of OptometryFullertonUSA

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