Skip to main content
SpringerLink
Log in

Effect of spatial averaging on the amplitude ring ratio in multifocal electroretinography

  • Technical Note
  • Published:
Documenta Ophthalmologica Aims and scope Submit manuscript

Abstract

Purpose

The purpose of this study was to evaluate the effect of spatial averaging on the multifocal electroretinography (mfERG) amplitude ring ratios used in screening for hydroxychloroquine (HCQ) toxicity.

Methods

This was a retrospective review of the records of patients screened for HCQ retinopathy at the USF Eye Institute (University of South Florida) during the period of 2015–2020. Patients were tested binocularly with Diagnosys mfERG system (Diagnosys LLC, Lowell, MA). Only the records of patients referred internally were used. The effects of the lowest level (level 1, or 8%) of spatial averaging on the P1 amplitude ring ratios used for screening of HCQ maculopathy: R1/R2, R2/R5, R5/R3 and R5/R4, were evaluated.

Results

The records of 40 patients (4 males, 36 females) aged 54.4 ± 14.1 years were selected for analysis. The use of spatial averaging had a significant effect on P1 amplitudes, and on the ring ratios and this effect was correlated with the magnitude of the amplitudes and the ratios. Spatial averaging diminished P1 amplitude significantly in ring 1 (p < 0.0001) and increased it slightly in ring 4 (p < 0.05), while it had no effect on the amplitude of the other three rings. Although as a group spatial averaging had a moderate effect on the R1/R2 ratio (~ −15%), on an individual basis the range was wide, from −36 to 43%. The effect on the other ring ratios was similar: The average group effect was ~ −5%, ~ −3.4% and ~ −4% for R2/R5, R5/R3 and R5/R4 ratios, but individual effects ranged from 0.18% to −27.3%, 0.9% to −14.2% and 0.9% to −26.2%, respectively.

Conclusions

For all ring ratios used in this analysis, spatial averaging has a substantial effect on the ring ratio, which could affect the interpretation of the results. Therefore, use of spatial averaging should be avoided when analyzing mfERG results for HCQ screening.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

References

  1. Poloschek CM, Sutter EE (2002) The fine structure of multifocal ERG topographies. J Vis 2:577–587. https://doi.org/10.1167/2.8.5

    Article  PubMed  Google Scholar 

  2. Fortune B, Johnson CA (2002) Decline of photopic multifocal electroretinogram responses with age is due primarily to preretinal optical factors. J Opt Soc Am A Opt Image Sci Vis 19:173–184. https://doi.org/10.1364/josaa.19.000173

    Article  PubMed  Google Scholar 

  3. Hood DC, Bach M, Brigell M, et al (2008) ISCEV guidelines for clinical multifocal electroretinography (2007 edition). Doc Ophthalmol 116: 1–11. doi: https://doi.org/10.1007/s10633-007-9089-2

  4. Hood DC, Bach M, Brigell M, et al (2012) ISCEV standard for clinical multifocal electroretinography (mfERG) (2011 edition). Doc Ophthalmol 124: 1–13. doi: https://doi.org/10.1007/s10633-011-9296-8.

  5. Hoffmann MB, Bach M, Kondo M et al (2021) ISCEV standard for clinical multifocal electroretinography (mfERG) (2021 update). Doc Ophthalmol 142:5–16. https://doi.org/10.1007/s10633-020-09812-w

    Article  PubMed  PubMed Central  Google Scholar 

  6. Lyons JS, Severns ML (2009) Using multifocal ERG ring ratios to detect and follow Plaquenil retinal toxicity: a review: Review of mfERG ring ratios in Plaquenil toxicity. Doc Ophthalmol 118:29–36. https://doi.org/10.1007/s10633-008-9130-0

    Article  PubMed  Google Scholar 

  7. Marmor MF, Kellner U, Lai TY et al (2011) Revised recommendations on screening for chloroquine and hydroxychloroquine retinopathy. Ophthalmology 118:415–422. https://doi.org/10.1016/j.ophtha.2010.11.017

    Article  PubMed  Google Scholar 

  8. Marmor MF, Kellner U, Lai TY et al (2016) Recommendations on screening for chloroquine and hydroxychloroquine retinopathy (2016 Revision). Ophthalmology 123:1386–1394. https://doi.org/10.1016/j.ophtha.2016.01.058

    Article  Google Scholar 

  9. Browning DJ, Lee C (2014) Test-retest variability of multifocal electroretinography in normal volunteers and short-term variability in hydroxychloroquine users. Clin Ophthalmol 8:1467–1473. https://doi.org/10.2147/OPTH.S66528

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Ludbrook J (2010) Confidence in Altman-Bland plots: a critical review of the method of differences. Clin Exp Pharmacol Physiol 37:143–149. https://doi.org/10.1111/j.1440-1681.2009.05288.x

    Article  CAS  PubMed  Google Scholar 

  11. Giavarina D (2015) Understanding Bland Altman analysis. Biochem Med (Zagreb) 25:141–151. https://doi.org/10.11613/BM.2015.015

    Article  Google Scholar 

  12. Ortiz G, Drucker D, Hyde C, et al (2020) The photopic negative response of the Light-adapted 3.0 ERG in clinical settings. Doc Ophthalmol 140: 115–128. doi: https://doi.org/10.1007/s10633-019-09723-5.

  13. Lyons JS, Severns ML (2007) Detection of early hydroxychloroquine retinal toxicity enhanced by ring ratio analysis of multifocal electroretinography. Am J Ophthalmol 143:801–809. https://doi.org/10.1016/j.ajo.2006.12.042

    Article  CAS  PubMed  Google Scholar 

  14. Tsang AC, Ahmadi Pirshahid S, Virgili G, et al (2015) Hydroxychloroquine and chloroquine retinopathy: a systematic review evaluating the multifocal electroretinogram as a screening test. Ophthalmology 122: 1239–1251-e4. doi: https://doi.org/10.1016/j.ophtha.2015.02.011.

  15. Bronson-Castain K, Bearse MA, Han Y et al (2005) An order effect in sequential testing using the multifocal electroretinogram (mfERG). Invest Ophthalmol Vis Sci 46:3437

    Google Scholar 

Download references

Acknowledgements

Parts of this work were presented at the 4th Annual Virtual Neural Engineering Symposium University of Miami (October 26–27, 2020), and at the 2021 ARVO Annual Meeting (May 1–June 30, virtual).

Funding

No funding was received for this research.

Author information

Authors and Affiliations

  1. Department of Ophthalmology, University of South Florida, Tampa, FL, 33620, USA

    Sara Bijan, Su-Yuan Yu, Gaurav Kiri, Swetangi Bhaleeya & Radouil Tzekov

Authors
  1. Sara Bijan
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Su-Yuan Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Gaurav Kiri
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Swetangi Bhaleeya
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Radouil Tzekov
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Corresponding author

Correspondence to Radouil Tzekov.

Ethics declarations

Ethical Approval

The study was approved by the local institutional review board.

Conflict of Interest

All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Statement of human rights

All procedures performed in studies involving human participants were in accordance with the ethical standards of the University Hospital Erlangen and University of South Florida and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Statement on the welfare of animals

Not applicable.

Informed consent

For this type of study formal consent is not required.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 493 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bijan, S., Yu, SY., Kiri, G. et al. Effect of spatial averaging on the amplitude ring ratio in multifocal electroretinography. Doc Ophthalmol 144, 41–52 (2022). https://doi.org/10.1007/s10633-021-09850-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10633-021-09850-y

Keywords

Search

Navigation