Dyschromatopsia and contrast sensitivity changes in COVID-19 patients

Aditi Sharma; Aditya Singh; Yashik Bansal; Aditi Mohan; Ramya Gnanaraj; Pranita Khulbe; Kavita Pangtey; Kaushiki Tripathi; Mohammad Ali Khan; Akshita Sharma; Manish Jain

doi:10.4103/IJO.IJO_1437_23

Dyschromatopsia and contrast sensitivity changes in COVID-19 patients

Indian J Ophthalmol. 2024 May 1;72(5):664-671. doi: 10.4103/IJO.IJO_1437_23. Epub 2023 Dec 26.

Authors

Affiliations

¹ Department of Ophthalmology, VCSG Government Institute of Medical Science and Research, Srinagar, Uttarakhand, India.
² Department of Microbiology, VCSG Government Institute of Medical Science and Research, Srinagar, Uttarakhand, India.
³ Postdoctoral Research Fellow at Sue Anschutz Rodgers Eye Center, Colorado, United States.
⁴ Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, L8P 1H6, Canada.
⁵ Department of Ophthalmology, Al Dhannah Hospital, Ruwais, Western Region, Abu Dhabi, UAE.

PMID: 38153970
DOI: 10.4103/IJO.IJO_1437_23

Abstract

Purpose: To evaluate the alterations in the psycho-physical tests, contrast sensitivity (CS) and hue discrimination (total estimation score, TES) in COVID-19 patients.

Methods: A prospective case-control study was undertaken in 2021-22 to look at CS and TES among COVID-19 patients and RT-PCR negative normal subjects by a mobile app "smart optometry" and X-Rite's free online version of Farnsworth-Munsell 100 hue test. Strict visual acuity (minimum of 6/9 equivalent on Snellen) and other clinical parameters were used as exclusion criteria to filter potentially confounding pre-receptoral co-morbid conditions. The effect of mismatch in recruiting age and sex matched controls during the pandemic were analyzed by multivariate linear regression.

Result: One-way ANOVA ruled out any influence of gender on CS and TES; however, there was significant difference in the TES on Mann Whitney U test (TES- 2.95 +/- 3.8 for cases; 0.30 +/- 1.1 for controls; p <0.001) and it persisted after accounting for age. Six controls with breakthrough infections had a significant deterioration in TES (Mean scores -3.0; 95% CI = -5.89 to -0.11; p = 0.04) on paired t test. Qualitative analysis showed that S-cone mediated deficiencies outnumber those affecting M-L cone mediated deficiencies. Among 53 subjects exhibiting three sensory features, anosmia, loss of taste and dyschromatopsia, nine (16.98%) had all features concurrently.

Conclusion: The study demonstrates that COVID-19 infection leads to altered TES representing dyschromatopsia -an ocular counterpart of anosmia, with little difference on CS.