Hong Kong Med J 2021 Jun;27(3):231 | Epub 11 Jun 2021
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
LETTER TO THE EDITOR
Ocular stroke and COVID-19
Sunny CL Au, MB, ChB, MRCSEd (Ophth); Callie KL Ko, MB, BS, FHKAM (Ophthalmology)
Department of Ophthalmology, Pamela Youde Nethersole Eastern Hospital and Tung Wah Eastern Hospital, Hong Kong
Corresponding author: Dr Sunny CL Au (kilihcua@gmail.com)
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To the Editor—Recent reports have linked retinal
vascular diseases with the hypercoagulability and
thromboembolic pathology of coronavirus disease
2019 (COVID-19). Central retinal artery occlusion
(CRAO), also known as ocular stroke, is a sight-threatening
ophthalmological emergency, and its
reported correlation with COVID-19 is of particular
interest to our territory-wide tertiary CRAO referral
centre in Hong Kong.
In a literature search, we found only three
case reports1 2 3 and two case series4 5 with at least
one patient with COVID-19 presenting with stroke
symptoms identified as CRAO. One case report on
ophthalmic artery occlusion was excluded. Acharya
et al1 reported a 60-year-old man with history of
hypertension, hyperlipidaemia, coronary artery
disease, and chronic obstructive pulmonary disease,
who presented with right CRAO 12 days after
testing positive for COVID-19. He had D-dimer level
42.131 (no unit provided), fibrinogen level >700 (no
unit provided), and C-reactive protein (CRP) level
7.02 (no unit provided). Montesel et al2 reported a
59-year-old man with history of hypertension and
hyperuricaemia who presented with left CRAO
69 days after testing positive for COVID-19. He
had D-dimer level 2.059 ng/mL, fibrinogen level
5.9 g/L, and CRP level 184 mg/L. Murchison et al,3
Sweid et al,4 and Alam et al,5 all affiliated with the
same institution, apparently described the same
patient, with similar lesion site and blood test results
(some minor differences and/or errors in reporting
notwithstanding). These authors all describe a
59-year-old man with history of hypertension who
presented with right CRAO after testing positive
for COVID-19 (date of positive test not reported).
He had D-dimer level 450 ng/mL, fibrinogen level
5.45 g/L, and CRP level 21 mg/L.
Central retinal artery occlusion is a rare disease
worldwide, with an estimated annual incidence of
0.85 per 100 000 population, which could account for the few published case reports. All cases had at least
one known risk factor for CRAO, with hypertension
being the commonest. The correlation of CRAO and
COVID-19 is uncertain, but we believe these cases
do not demonstrate any causal link.
Author contributions
SCL Au drafted the letter and all authors contributed to the critical revision of the letter for important intellectual content. All authors approved the final version for publication and take
responsibility for its accuracy and integrity.
Conflicts of interest
All authors have disclosed no conflicts of interest.
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
References
1. Acharya S, Diamond M, Anwar S, Glaser A, Tyagi P. Unique case of central retinal artery occlusion secondary
to COVID-19 disease. IDCases 2020;21:e00867. Crossref
2. Montesel A, Bucolo C, Mouvet V, Moret E, Eandi CM. Case report: central retinal artery occlusion in a COVID-19
patient. Front Pharmacol 2020;11:588384. Crossref
3. Murchison AP, Sweid A, Dharia R, et al. Monocular visual loss as the presenting symptom of COVID-19 infection.
Clin Neurol Neurosurg 2020;201:106440. Crossref
4. Sweid A, Hammoud B, Weinberg JH, et al. Letter: thrombotic neurovascular disease in COVID-19 patients.
Neurosurgery 2020;87:E400-6. Crossref
5. Alam S, Dharia RN, Miller E, Rincon F, Tzeng DL, Bell RD. Coronavirus positive patients presenting with stroke-like
symptoms. J Stroke Cerebrovasc Dis 2021;30:105588. Crossref