General and Ocular Pathology
This domain tests general pathologic processes and their ocular manifestations: injury, inflammation, repair, degeneration, and neoplasia. Questions emphasize pattern recognition and clinicopathologic correlation.
Core rules
- Reversible cell injury shows swelling; irreversible injury shows membrane failure, ATP depletion, and necrosis. Apoptosis is programmed and less inflammatory.
- Acute inflammation features neutrophils and edema; chronic inflammation features lymphocytes, macrophages, and fibrosis. Granulomas suggest tuberculosis, sarcoidosis, or fungal disease.
- Corneal dystrophies are bilateral, inherited, and noninflammatory: epithelial basement membrane dystrophy, granular dystrophy (hyaline deposits), lattice dystrophy (amyloid), and Fuchs endothelial dystrophy.
- Wound healing: corneal epithelium slides and proliferates; stromal keratocytes lay down collagen and may cause scarring; endothelium does not regenerate well in humans.
- Uveal melanoma metastasizes most often to the liver; choroidal metastasis most often arises from breast or lung.
Worked example
A pigmented choroidal lesion is evaluated. Reasoning: features favoring melanoma over nevus include thickness greater than about 2 mm, subretinal fluid, lipofuscin, symptoms, and documented growth. Small melanomas may be observed or treated with plaque radiotherapy, but biopsy is generally avoided because of dissemination risk; systemic surveillance focuses on the liver.
Traps that cost marks
- Mixing up granular and lattice dystrophy: granular is hyaline, lattice is amyloid.
- Assigning Fuchs dystrophy to the stroma; it is an endothelial disease.
- Equating optic disc cupping with glaucoma without considering physiologic cupping or other neuropathies.