Corneal Opacities: Classification & Clinical Significance
Exam-essential patterns for ophthalmology.
1. Morphological Classification
Corneal opacities are classified by depth and density, which determines visual prognosis.
| Type | Description |
|---|---|
| Nebula | Faint, hazy opacity; iris details are visible through it. |
| Macula | Moderately dense; iris details are partially obscured. |
| Leukoma | Dense, white opacity; iris details are completely obscured. |
2. Important Clinical Variants
- Adherent Leukoma: A leukoma where the iris is incarcerated into the corneal defect (often after a healed perforated ulcer).
- Corneal Facet: A depressed area on the cornea resulting from healing of a superficial ulcer without filling the defect.
- Corneal Dystrophies: Bilateral, genetic, progressive opacities (e.g., Granular, Lattice, Macular dystrophy).
3. NEET PG High-Yield Pearls
- Management: Therapeutic options include optical iridectomy (if pupil is clear), contact lenses, lamellar keratoplasty, or penetrating keratoplasty (PKP).
- Macular Dystrophy: The most common autosomal recessive dystrophy, characterized by deposits of mucopolysaccharides (stains with Alcian blue).
- Granular Dystrophy: Characterized by hyaline deposits (stains with Masson’s trichrome).
- Lattice Dystrophy: Characterized by amyloid deposits (stains with Congo red).