Board Certified Ophthalmologist Uveitis and Ocular Inflammation 2 — Questions and Answers
Question 1: Which laboratory test is most useful in the initial workup of a patient with suspected sarcoid uveitis?
- Antinuclear antibody (ANA)
- Serum angiotensin-converting enzyme (ACE) (Correct answer)
- HLA-B27 typing
- Antineutrophil cytoplasmic antibody (ANCA)
Correct answer: Serum angiotensin-converting enzyme (ACE)
Serum ACE is elevated in approximately 60–75% of patients with active sarcoidosis and is a useful screening test for sarcoid uveitis, though it lacks specificity.
Question 2: What is the most common cause of infectious posterior uveitis in immunocompetent patients in the United States?
- Cytomegalovirus (CMV)
- Toxoplasma gondii (Correct answer)
- Herpes simplex virus (HSV)
- Candida albicans
Correct answer: Toxoplasma gondii
Toxoplasma gondii is the most common cause of infectious posterior uveitis in immunocompetent individuals, presenting as focal retinochoroiditis typically adjacent to an old pigmented scar.
Question 3: Which fundus finding is most characteristic of active toxoplasmic retinochoroiditis?
- Dalen-Fuchs nodules at the level of the RPE
- White fluffy lesion adjacent to an old pigmented scar ('headlight in fog') (Correct answer)
- Perivascular candle-wax dripping exudates
- Epiretinal membrane over the macula
Correct answer: White fluffy lesion adjacent to an old pigmented scar ('headlight in fog')
Active toxoplasmic retinochoroiditis characteristically shows a white, fluffy active lesion adjacent to an old pigmented chorioretinal scar, producing the classic 'headlight in fog' appearance.
Question 4: An AIDS patient develops painless progressive vision loss with a 'pizza pie' fundus appearance showing retinal whitening and hemorrhage. What is the most likely diagnosis?
- Toxoplasmic retinitis
- Acute retinal necrosis (ARN)
- CMV retinitis (Correct answer)
- Progressive outer retinal necrosis (PORN)
Correct answer: CMV retinitis
CMV retinitis in immunocompromised patients classically presents with a 'pizza pie' or 'scrambled eggs and ketchup' appearance of retinal whitening (necrosis) with hemorrhage along vascular arcades.
Question 5: Which anterior chamber finding is characteristic of Fuchs heterochromic iridocyclitis (FHI)?
- Large mutton-fat KPs with posterior synechiae
- Posterior synechiae and iris bombe
- Fine stellate KPs distributed across the entire corneal endothelium without posterior synechiae (Correct answer)
- Dense hypopyon with fibrin in the anterior chamber
Correct answer: Fine stellate KPs distributed across the entire corneal endothelium without posterior synechiae
FHI is characterized by fine stellate KPs distributed across the entire corneal endothelium without posterior synechiae formation, distinguishing it from other forms of chronic anterior uveitis.
Question 6: In a patient receiving long-term systemic corticosteroids for uveitis, which ocular complication is most characteristic of steroid use?
- Anterior subcapsular cataract
- Posterior subcapsular cataract (Correct answer)
- Nuclear sclerotic cataract
- Cortical cataract
Correct answer: Posterior subcapsular cataract
Posterior subcapsular cataracts (PSC) are the classic ocular complication of both systemic and topical corticosteroid use, developing in a dose- and duration-dependent manner.
Question 7: What is the mechanism of action of cyclosporine when used as a steroid-sparing agent in uveitis?
- Inhibits TNF-alpha production by macrophages
- Blocks calcineurin, preventing IL-2 transcription and T-cell activation (Correct answer)
- Inhibits dihydrofolate reductase and lymphocyte proliferation
- Depletes peripheral B lymphocytes via CD20 targeting
Correct answer: Blocks calcineurin, preventing IL-2 transcription and T-cell activation
Cyclosporine inhibits calcineurin, thereby blocking IL-2 gene transcription and T-cell activation, which is effective in immune-mediated uveitis requiring steroid-sparing therapy.
Board Certified Ophthalmologist Uveitis and Ocular Inflammation 2
Which laboratory test is most useful in the initial workup of a patient with suspected sarcoid uveitis?