On the Quest for Ophthalmological Biomarkers for Long COVID: A Scoping Review
Abstract
1. Introduction
2. Materials and Methods
2.1. Registration and Reporting
2.2. Search Strategy
2.3. Study Eligibility
- Studies of clinical populations being investigated for long COVID.
- Studies using automated technology for measuring the above symptoms.
- Studies reporting ophthalmological parameters and outcome measures relevant to the clinical management of patient populations.
- Studies on fundoscopy.
- Studies on post-vaccination populations.
- Studies on healthy populations (unless healthy control comparator data were reported separately in a study also reporting on a patient population).
2.4. Study Selection
2.5. Data Extraction and Synthesis
3. Results
3.1. Summary of Results
3.2. Study Characteristics
3.2.1. Study Types
3.2.2. Study Demographics
3.2.3. Ophthalmological Signal Types
3.2.4. Technologies
3.2.5. Ophthalmological Abnormalities
4. Discussion
5. Conclusions
Supplementary Materials
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
Abbreviations
CDC | Centers for Disease Control and Prevention |
CSF | cerebrospinal fluid |
EOG | electroretinogram |
ERG | electrooculogram |
NICE | National Institute for Health and Care Excellence |
TSD | time since diagnosis |
PLR | pupillary light reflex |
VEP | visual evoked potential |
OVRT-C | Oculomotor Vestibular Reaction Time Cognitive test |
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Author&Year | N 1 | Controls | Male | Female | Age (Years) | Setting | Days Since Diagnosis (Days) 2 |
---|---|---|---|---|---|---|---|
Carbone 2022 [20] | 78 | 23 | 41 | 37 | 55.2 ± 12.2 | University | 419.1 ± 26.0 |
De Giglio 2023 [36] | 1 | 0 | 1 | 0 | 74 | Hospital | 60 |
Kelly 2022 [28] | 377 | 300 | 245 | 132 | 28.4 ± 7.4 | Hospital and university | >28 |
Bitirgen 2022 [24] | 65 | 30 | NA | NA | 42.5 ± 10.7 | University hospital | 120 (60–150) |
Garcia 2022 [29] | 18 | 9 | 10 | 8 | 49.56 ± 9.14 | University hospital | NA |
Abdelrahman 2021 [25] | 20 | 0 | 10 | 10 | 40 ± 9.58 | Hospital | NA |
Bellavia 2021 [26] | 40 | 20 | 27 | 13 | 54.3 ± 16.7 | Hospital | NA |
Koskderelioglu 2022 [30] | 120 | 44 | 48 | 72 | 39.0 ± 9.6 | University | 132 ± 66 (30–360) |
Braceros 2021 [35] | 1 | 0 | 1 | 0 | 28 | Hospital | 30 |
Sabel 2021 [37] | 2 | 0 | 0 | 2 | 56 ± 16 | Hospital | >28 |
González-Vides 2024 [32] | 117 | 42 | 31 | 86 | 48.9 ± 11.15 | Hospital and university | 600 |
Jan Johansson 2024 [31] | 38 | 0 | 9 | 29 | 46.8 ± 9.3 | Hospital | 660 (360–870) |
Moritz Güttes 2024 [33] | 179 | 49 | 88 | 91 | 35.63 ± 11 | University hospital | 442.49 ± 215 |
Vinuela-Navarro 2023 [27] | 85 | 20 | 22 | 63 | 49.03 ± 6.67 | Hospital | >28 |
Mehringer 2023 [34] | 35 | 15 | 19 | 16 | 27.29 ± 3.84 | University | 389.25 ± 189.34 |
Ophthalmological Feature | Abnormalities Detected | Related Literature |
---|---|---|
Saccadic feature | Higher saccade error rate | [20,28,29,31,33] |
Prolonged saccade latency (reaction time) | [27,29,31,32,33] | |
Pursuit feature | Smooth pursuit abnormal (disrupted or unstable) | [27,28] |
Nystagmus feature | Nystagmus (optokinetic and positional) abnormal | [25,28] |
Caloric weakness | [25] | |
Pupillary reflex feature | Increased latency of pupil contraction | [24] |
Reduced duration of pupil contraction | [24] | |
Reduced latency of pupil dilation | [24] | |
Higher dilatation velocity | [26] | |
Higher absolute constriction amplitude | [26] | |
Higher constriction index | [26] | |
Higher baseline pupil diameter | [26] | |
Reduced pupil constriction | [27] | |
Reduced pupil dilation | [27] | |
Visual field feature | Suppression of static visual field perimetry | [35] |
Impaired peripheral field defects | [37] | |
VEP feature | Reduced VEP * amplitude | [30,35] |
Prolonged p100 latencies | [30] | |
Abnormalities in several peripheral nerve measurements | [30] | |
Stereopsis performance feature | Increased reaction time | [33,34] |
Other features | Mild macular thickening | [35] |
Abnormal ERG * implicit times | [35] | |
Suppressed EOG * amplitude | [35] |
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Su, W.; Statham, L.; Jammal, C.; Pecchia, L.; Hoad, D.; Piaggio, D. On the Quest for Ophthalmological Biomarkers for Long COVID: A Scoping Review. Appl. Sci. 2025, 15, 6126. https://doi.org/10.3390/app15116126
Su W, Statham L, Jammal C, Pecchia L, Hoad D, Piaggio D. On the Quest for Ophthalmological Biomarkers for Long COVID: A Scoping Review. Applied Sciences. 2025; 15(11):6126. https://doi.org/10.3390/app15116126
Chicago/Turabian StyleSu, Wanzi, Laura Statham, Carla Jammal, Leandro Pecchia, Damon Hoad, and Davide Piaggio. 2025. "On the Quest for Ophthalmological Biomarkers for Long COVID: A Scoping Review" Applied Sciences 15, no. 11: 6126. https://doi.org/10.3390/app15116126
APA StyleSu, W., Statham, L., Jammal, C., Pecchia, L., Hoad, D., & Piaggio, D. (2025). On the Quest for Ophthalmological Biomarkers for Long COVID: A Scoping Review. Applied Sciences, 15(11), 6126. https://doi.org/10.3390/app15116126