Through the Eyes of Uncertainty: Giant Cell Arteritis and Lyme Neuroborreliosis in a Story of Vision Loss.

Acute vision loss is a prevalent clinical manifestation associated with a broad spectrum of differential diagnoses, encompassing demyelinating diseases, neoplastic processes, autoimmune disorders, and infectious conditions. A rare but noteworthy infectious etiology contributing to acute vision loss is neurological Lyme disease (Lyme neuroborreliosis)-induced optic neuritis. Lyme disease, a vector-borne illness caused by the spirochete , has the potential to affect multiple physiological systems and unfolds in three distinct stages. Another significant contributor to acute vision loss is giant cell arteritis, an autoimmune vasculitis that commonly affects large- and medium-sized vessels, including the temporal and ophthalmic arteries. This relatively common condition may manifest with symptoms, such as jaw claudication, headaches, and visual disturbances. The precise identification of the underlying cause of acute visual loss is of utmost importance for physicians, as it is instrumental in averting undesirable complications. An 80-year-old female presents to the emergency room with a sudden onset of blurry vision of the left eye, right-sided weakness, dysarthria, jaw pain, headache, and left facial droop. Following consultations with rheumatology and ophthalmology specialists, giant cell arteritis emerged as a primary consideration in the differential diagnosis for the observed vision loss. Subsequently, a temporal artery biopsy was conducted, definitively confirming the diagnosis of giant cell arteritis. Considering the patient's residence in an area endemic to Lyme disease, a Lyme immunoglobulin G (IgG) titer was ordered. The results returned positive, suggesting the presence of Lyme neuroborreliosis.