Superior Ophthalmic Vein Thrombosis: A Case Report in a Previously Healthy Methicillin-Resistant -Positive Patient

Background

Superior ophthalmic vein thrombosis (SOVT) is a very rare condition, with an incidence rate of 3 to 4 cases per million per year [1], and can be classified according to the underlying etiology into septic and aseptic SOVT. Signs of venous congestion will usually be the presenting symptoms of SOVT and include chemosis, ophthalmoplegia, and eyelid swelling. In this report, we present a case of right SOVT in a patient with a methicillin-resistant Staphylococcus aureus (MRSA)-positive blood culture. The patient was treated successfully with antibiotics and anticoagulants.

Case Report

A 38-year-old woman, previously healthy, presented to the Emergency Department with a 2-week history of worsening unilateral right-sided headache. Her symptoms started as dizziness 1 week before the headache, but she was able to tolerate it. In the first week, the headache was throbbing and responding to analgesia. In the second week, it was continuous, increased in intensity to 10 out of 10, and was associated with photophobia and phonophobia. The patient also presented with right upper lid swelling, redness, and blurred vision but denied changes in color perception. She reported right-sided ear pain and tinnitus. Ocular examination revealed right upper lid edema, proptosis, and diplopia in all gazes, mainly vertical. The best corrected visual acuity was 6/12 in the right eye and 6/6 in the left eye, with no relative afferent pupillary defect. The color vision and visual field were intact. The intraocular pressure measurements in the right and left eye were 18 and 12 mmHg, respectively. Slit-lamp examination showed right upper eyelid edema, conjunctival congestion, and clear cornea. The fundus examination showed a raised hyperemic right optic disc with blurred margins and a normal left optic disc. The extraocular eye movements were limited in all directions, especially in the lateral gaze up. The patient’s vital signs were stable, and her physical examination of other systems was un-remarkable. She was seen by an ear, nose, and throat specialist, and there were no signs of otitis media.

The patient had no history of contact with COVID-19-infected patients, and her nasopharyngeal swab for SARS-CoV-2 was negative. She had received 2 doses of AstraZeneca ChAdOx1 nCoV-19 vaccine 2 months apart, with the second one 8 months before presentation. The patient tested positive for the IgG COVID-19 antibody test.

Laboratory investigations showed a positive blood culture of MRSA and elevated levels of the inflammatory markers erythrocyte sedimentation rate and C-reactive protein, at 93 mm/h and 102 mg/L, respectively, and D-dimer level of 419 ng/mL.

All results from the following investigations were negative: complete blood count, thyroid-stimulating hormone level, cardiovascular disease panel, hypercoagulability tests including APCR, protein-C, protein-S, antiphospholipid antibodies, anti-thrombin III (ATIII), and factor-V-Leiden mutation. Autoimmune workup was unremarkable for antinuclear antibody, anti-double stranded DNA, lupus anticoagulant, and rheumatoid factor. A brain computed tomography (CT) angiography examination was unremarkable. Orbital CT examination showed periorbital and orbital cellulitis (Figure 1), with superior ophthalmic vein thrombosis (Figure 2).

The patient was started on vancomycin (2×1-1.5 g, based on vancomycin trough level), flagyl (3×500 mg), and anticoagulant therapy (enoxaparin injection 1 mL per kg). She was discharged home on oral antibiotics and warfarin, with outpatient follow-up. At the 1-month follow-up, the patient was compliant with medications and reported full resolution of symptoms, with no visual acuity impairment.

Discussion

The superior ophthalmic vein is responsible for most of the venous drainage of the orbit. SOVT can be classified according to the underlying etiology into septic and aseptic. Most reported cases (66.7%) are aseptic SOVT [2]. Signs of venous congestion will usually be the presenting symptoms of SOVT and include chemosis, ophthalmoplegia, and eyelid swelling.

SOVT can be presented as unilateral or bilateral and can be associated with cavernous sinus thrombosis [3].

Sotoudeh et al found that the most common cause of SOVT is orbital cellulitis, which was detected in 50% of cases, and the most common organism is Staphylococcus aureus [3]. Two cases of SOVT with positive MRSA were reported in the literature and both were associated with the intravenous use of illicit drugs [4,5]; however, our patient denied intravenous use of illicit drugs. Although our patient’s blood culture was positive for MRSA, signs and symptoms such as fever, rigors, and leukocytosis were absent.

MRSA is usually present in healthcare facilities; however, in the 1990s many cases of community-associated MRSA (CA-MRSA) infections were reported in patients with no risk factors or previous exposure to healthcare facilities [6]. The most common sources of MRSA isolates in our region were found to be skin and soft tissue infections [6]. CA-MRSA has shown a significant rise in healthcare facilities throughout Gulf Cooperation Council countries [6]. In Kuwait, the prevalence rates of CA-MRSA from isolates collected in 2005, 2010, and 2019 were 24%, 45%, and 60%, respectively [7–9].

The AstraZeneca ChAdOx1-S/nCoV-19 vaccine is 1 of 4 vaccines that received conditional approval for the prevention of COVID-19 in the United Kingdom (November 2021). In our case, the association between SOVT and the vaccine is less likely, since her last dose was 8 months before presentation. SOVT has been reported as one of the ocular manifestations occurring after 10 days of receiving AstraZeneca ChAdOx1-S/nCoV-19 in 2 case reports [10,11].

CT or MRI venography are the modalities of choice to diagnose SOVT. The primary findings include a dilated superior ophthalmic vein with linear filling defects on CT or MRI venography. Management of SOVT mainly depends on the underlying etiologies and includes antibiotics, anticoagulants, and surgery. Vancomycin is the drug of choice to manage invasive MRSA infection. Fortunately, most reports in our region stated no vancomycin resistance in MRSA. Unfortunately, there is no clear treatment guideline for SOVT.

Conclusions

In conclusion, SOVT is a very challenging ophthalmic condition and can be present concurrent with orbital cellulitis or cavernous sinus thrombosis. Early imaging studies and proper management are important to prevent serious complications.

Ophthalmologists need to be alerted to the high prevalence of MRSA worldwide and to the importance of tailoring antibiotics based on the causative agent, to decrease the risk of therapeutic failure and microbial resistance.