Reduced Visual Field Activity Due to Covid-19 in a Patient With a Pituitary Macroadenoma

Background: Vision changes can be the presenting symptom of pituitary macroadenomas. The first-line therapy is transsphenoidal resection except for macroprolactinomas where medical therapy with dopamine agonist (DA) is the initial treatment of choice. Surgical resection is reserved if treatment with DA did not result in decreased serum prolactin (PRL), size of adenoma and/or alleviation of symptoms. With the Covid-19 pandemic, there have been a variety of symptoms reported including ophthalmic manifestations (1). We will present how an acute decrease in vision from Covid-19 nearly led to surgical intervention of macroprolactinoma. Clinical Case: A 61-year-old woman presented to the emergency room (ER) with complaints of headache in 6/2020. MRI Brain showed a 4.0 x 4.0 x 4.5 cm pituitary macroadenoma with suprasellar extension and invasion of the cavernous sinuses. The mass engulfed the adjacent circle of Willis, the MCAs bilaterally, the PCAs and the superior aspect of the vertebrobasilar system. Initial PRL was 7441 ng/mL (5.2-26.25 ng/mL). She was discharged on Cabergoline 0.25 mg twice weekly. Visual field exam showed mild nonspecific field defects in the right eye and larger diffuse field defects in the left eye slightly more temporal. One month later, Cabergoline dose was increased to 0.5 mg twice weekly with PRL drop to 1161.7 ng/mL. In 8/2020, she started to complain of worsening vision. Ophthalmological exam showed worsening visual fields in both eyes and the optic discs showed temporal pallor. She was referred to ER where she tested positive for Covid-19 and was admitted. CT Head showed stable partially calcified enhancing sellar and suprasellar mass. Repeat PRL was 635.6 ng/mL. Despite reduction in PRL, transsphenoidal resection was considered but was deferred to 9/2020 due to Covid-19. Follow up appointment with Neuro-ophthalmology in 9/2020 prior to scheduled surgery, showed visual field improvement with just mild nonspecific defects and surgery was canceled. PRL in 10/2020 decreased to 239.1 ng/mL. Patient’s visual fields continued to improve after recovery from Covid-19 and with reduction in PRL. It was determined that the patient’s reduction in visual fields was due to Covid-19 and not her macroadenoma. Conclusion: There have not been many reported cases of decreased visual fields due to Covid-19 (1). Proposed mechanisms include expression of ACE-2 receptors in the aqueous humor, which is the main receptor for Covid-19, and thromboembolic disease (1). More studies and data are needed to conclude the mechanism of decreased visual fields. This will avoid unnecessary surgical interventions for patients with macroprolactinomas. References: 1. Ho, D., Low, R., Tong, L., et al. COVID-19 and the Ocular Surface: A Review of Transmission and Manifestations. Ocul Immunol Inflamm. 2020 Jul 3;28(5):726-734.