Abstract | April 6, 2022

Irreversible monocular vision loss in times of pandemic

Presenting Author: Harsh Sharma, MBBS, MD, Internal Medicine Resident PGY1, Department of Internal Medicine, North Alabama Medical Center, Florence, AL

Coauthors: Mohammed Afraz Pasha, MD, Internal Medicine, PGY2, North Alabama Medical Center, Florence, AL; Manjyot Bajwa, MD, Internal Medicine, PGY2, North Alabama Medical Center, Florence, AL; Sucheta Kundu, MD, Internal Medicine, PGY2, North Alabama Medical Center, Florence, AL; Kavitha Juvvala, MD, Internal Medicine, PGY3, North Alabama Medical Center, Florence, AL; Jan Westerman, MD, Director, Critical Care, North Alabama Medical Center, Florence, AL

Learning Objectives

  1. With risk of severe hyperglycemia, steroids must be used with caution in biopsy negative patients with clinical suspicion of GCA.
  2. In patients presenting with headache and vision loss, early brain imaging must be considered to evaluate for pituitary cause of vision and prevent irreversible blindness. MRI is more sensitive than CT in detection of pituitary adenoma.

Introduction: Pituitary tumors can present as progressive unilateral vision loss due to compressive optic neuropathy or bilateral vision loss due to compression of the optic chiasm. Giant cell arteritis (GCA) can cause partial or complete vision loss which is irreversible in about 20% patients. This occurs mostly due to anterior arteritic optic neuropathy, which is preventable by early corticosteroids use. While neuroimaging with an MRI is the investigation of choice for diagnosis of pituitary mass, temporal artery biopsy is the gold standard for GCA diagnosis. Alternative diagnosis must be ruled out in patients with clinical suspicion of GCA to prevent irreversible vision loss.

Case Presentation: A 70-year-old Caucasian female presented to the ER with 2 weeks history of polyuria, polydipsia and generalized weakness. She developed altered mental status 2 days prior to presentation. About 3 weeks ago, she had painless and progressive right eye vision loss. On outpatient evaluation, she was initiated on high dose prednisone for clinical suspicion of GCA and temporal artery biopsy was deferred due to risk of exposure to COVID-19. Consequently, she remained on high dose steroid therapy based on clinical suspicion of GCA. On presentation, blood pressure was 177/87 mmHg, heart rate was 106 bpm. On physical examination, she was confused and visual acuity could not be determined. Laboratory investigations showed WBC 14.2×103/µL, lactate 2.4mmol/L, sodium 129mmol/L, creatinine 1.6mg/Dl, glucose 853mg/dL, anion gap 31, pH 7.19, bicarbonate 7mmol/L, beta-hydroxybutyrate 13.1mmol/L and positive urine ketones.

Working Diagnosis: Patient’s presentation and laboratory investigations were consistent with diabetic ketoacidosis (DKA), likely precipitated by high dose prednisone. CT brain performed for evaluation of encephalopathy revealed a large suprasellar mass. MRI brain revealed a 4.4cm x 2.4cm soft tissue lesion arising within the pituitary fossa extending superiorly to midbrain with compression of optic chiasm suggesting possibility of pituitary cyst or adenoma. Hormonal evaluation revealed decreased levels of free T4, FSH, LH and prolactin.

Management: DKA resolved with fluid resuscitation, electrolyte replacement and intravenous insulin infusion. She was initiated on thyroxine and hydrocortisone and recommended an outpatient endocrinology follow-up. With near complete vision loss, neurosurgery team advised consideration of elective surgery to prevent further progression.