Systemic Disease and Ocular Manifestations
Core framework
Link systemic conditions to their hallmark ocular findings. Focus on diabetes, hypertension, autoimmune disease, infectious disease, and thyroid disease, since these dominate exam questions.
Concepts to know cold
- Diabetes: nonproliferative (microaneurysms, dot-blot hemorrhages, hard exudates) vs proliferative (neovascularization). Also cataract and fluctuating refraction with glycemic change.
- Hypertension: arteriolar narrowing, AV nicking, flame hemorrhages, cotton-wool spots, papilledema in malignant hypertension.
- Autoimmune: dry eye and scleritis in rheumatoid arthritis; keratoconjunctivitis sicca in Sjögren; iritis in HLA-B27 disease.
- Thyroid eye disease: proptosis, lid retraction, restrictive myopathy (inferior rectus most often), optic neuropathy in severe cases.
- Infectious: toxoplasmosis (focal retinochoroiditis), herpes zoster ophthalmicus (dendritic or pseudodendritic keratitis, Hutchinson sign).
Traps
Questions mix up diabetic retinopathy stages or attribute findings to the wrong systemic disease. Remember that cotton-wool spots indicate ischemia, not exudate.
Rule of thumb
New bilateral or atypical ocular inflammation should prompt a systemic workup. The eye is often the first sign of systemic disease.
Worked example
A patient with rheumatoid arthritis presents with severe deep eye pain and a violaceous sclera. This suggests scleritis, which can threaten the globe and is associated with systemic autoimmune disease; urgent evaluation and systemic workup are indicated.