Lupus Retinopathy Mimicking Ocular Tuberculosis: A Diagnostic Dilemma

Systemic lupus erythematosus (SLE) or Lupus is often called the "great mimicker" due to its ability to mimic other systemic disorders. SLE is a multisystem autoimmune disorder with varied manifestations, including ocular involvement. Retinal vascular occlusions are an uncommon but potentially vision-threatening presentation of lupus retinopathy. When coexisting systemic features mimic infectious etiologies such as tuberculosis (TB), diagnosis becomes challenging, delaying appropriate immunosuppressive therapy. We report a diagnostically complex case of a 22-year-old female who presented with sudden, painless loss of vision in the right eye. Initially, she was diagnosed elsewhere as macular branch retinal artery occlusion (BRAO) and chorioretinitis. Systemic symptoms-weight loss, low-grade fever, and neuropathy-along with a positive sputum smear and chest radiograph findings, led to a provisional diagnosis of pulmonary tuberculosis with presumed ocular TB. She was started on anti-tubercular therapy (ATT) and oral corticosteroids. Upon further evaluation at our center, additional ocular findings included disc pallor, active vasculitis, and bilateral chorioretinitis. Imaging studies (Fundus Fluorescein Angiography (FFA), Indocyanine Green Angiography (ICGA), Optical Coherence Tomography (OCT)) confirmed retinal vasculitis. A dermatologic evaluation of her facial rash was inconclusive for SLE. However, subsequent worsening of systemic symptoms and neuropsychiatric events prompted re-investigation. Specific MRI findings and immunological tests that revealed strong positivity for anti-Smith, anti-ribonucleoprotein (anti-RNP), anti-Ro-52, and anti-double-stranded deoxyribonucleic acid (anti-dsDNA) antibodies with hypocomplementemia confirmed the diagnosis of neuropsychiatric SLE (NPSLE). ATT was discontinued, and the patient was treated with intravenous steroids and cyclophosphamide and later transitioned to mycophenolate mofetil. Over a year, the patient showed significant systemic and ocular improvement, with best-corrected visual acuity in the affected eye improving from perception of light to 6/60. This case highlights the diagnostic dilemma in distinguishing retinal vasculitis of autoimmune etiology from that due to infectious causes such as tuberculosis, especially in endemic regions. Ocular involvement can be an early sign of systemic SLE, underscoring the need for high clinical suspicion, systemic correlation, and immunological workup in young patients with retinal vascular occlusions. Early recognition of lupus retinopathy and timely immunosuppression are key to preserving vision and preventing systemic morbidity.