Presenting Complaint

The patient is a 24-year-old female presenting with sudden onset of left eye visual loss, accompanied by a red and painful eye. She has a history of ulcerative colitis, which has been well-controlled, with only one flare-up in the last four years, and no history of thrombotic events.

History of Presenting Complaint (HPC)

• The visual loss occurred suddenly, indicating a possible vascular or inflammatory cause.
• The presence of a red and painful eye suggests inflammation or infection.
• The patient's history of ulcerative colitis is significant, as it can be associated with extraintestinal manifestations, including eye conditions.

Differential Diagnosis (DD)

Single Most Likely Diagnosis

• Optic Neuritis: Given the sudden onset of visual loss and the presence of pain, optic neuritis is a strong consideration. It is an inflammatory condition of the optic nerve and can be associated with demyelinating diseases, but it also occurs in isolation or in the context of systemic diseases like ulcerative colitis.

Other Likely Diagnoses

• Central Retinal Artery Occlusion (CRAO): Although less likely given the patient's age and lack of thrombotic history, CRAO can cause sudden painless loss of vision. However, the presence of pain and a red eye makes this less likely.
• Anterior Uveitis: This condition, often associated with autoimmune diseases like ulcerative colitis, can cause a painful, red eye with decreased vision. It's a plausible diagnosis given the patient's history.
• Retinal Detachment: While it can cause sudden visual loss, it is typically painless and might not fully explain the redness and pain unless there's associated inflammation.

Do Not Miss Diagnoses

• Giant Cell Arteritis: Although rare in someone as young as 24, giant cell arteritis can cause sudden visual loss and is a medical emergency. It's essential to consider, especially if there are systemic symptoms like headache or jaw claudication.
• Endophthalmitis: An infectious condition that can follow trauma or surgery, endophthalmitis is a medical emergency requiring prompt treatment. The presence of a red, painful eye with vision loss necessitates consideration of this diagnosis.

Rare Diagnoses

• Susac Syndrome: A rare condition characterized by microangiopathic changes in the brain and retina, leading to visual loss. It's more common in young women but is much less likely than other diagnoses.
• Eale Disease: A rare idiopathic condition causing retinal vasculitis and potentially leading to visual loss. It's more common in young adults but is less likely given the acute presentation and associated symptoms.

Investigation

• Visual Acuity Testing: To quantify the extent of visual loss.
• Slit-Lamp Examination: To assess the anterior segment for signs of uveitis or other inflammatory conditions.
• Fundoscopy: To evaluate the retina and optic nerve for signs of disease.
• Imaging (MRI/OCT): To assess the optic nerve and retina in more detail, especially if optic neuritis or retinal detachment is suspected.
• Blood Tests: To evaluate for inflammatory markers, autoimmune diseases, and to rule out conditions like giant cell arteritis.
• Ulcerative Colitis Disease Activity Assessment: To understand the current state of the patient's ulcerative colitis.

Management

• Depends on the Diagnosis:
  • Optic Neuritis: High-dose corticosteroids.
  • Anterior Uveitis: Topical corticosteroids and mydriatics.
  • Central Retinal Artery Occlusion: Immediate ophthalmological consultation for potential thrombolysis or other interventions.
  • Giant Cell Arteritis: High-dose corticosteroids and potentially other immunosuppressants.
  • Endophthalmitis: Intravitreal antibiotics and possibly vitrectomy.
• Multidisciplinary Approach: Involving ophthalmology, gastroenterology (for ulcerative colitis management), and potentially rheumatology or neurology depending on the underlying diagnosis.