Cornea/lens pathology Flashcards
Anterior subcapsular cataract
may form when posterior synchiae cause hypoxia or anoxia of the lens epithelium –> metaplastic response of the epithelium, which forms fibrous plaques mixed in whit basement membrane.
Peter’s anomaly
central opacity present at birth +/- iridocorneal adhesions. Bilateral in > 50% of cases, and may be assoc/w/systemic abnormalities in > 50% of patients.
PAM
primary acquired melanosis without atypia* which his unlikely to progress to melanoma, and can grow slowly in size even without malignant transformation
*Histopathology of basilar layer of epithelium = pigmented but without any signs of atypia (no mitotic figures, prominent nucleoli)
PAM with atypia has ~50% chance of transforming into malignant melanoma.
Reis Buckler corneal dystrophy (RBCD) and Thiel-Behnke (TBCD)
confluent and coarse geographic opacities at the level of Bowman’s layer and the superficial stroma. Usually present in 1st decade. AD.
painful recurrent erosions during the 1st/2nd decade of life
Hard to distinguish from TCBD but RBCD (more severe), can lead to more severe stromal scarring. These two dystrophies can only be truly differentiated from each other on electron microscopy since TBCD has “curly fibers”
BBB = behnkle, buckler affect Bowman’s
Rubella cataract
Retained lens fiber nuceli.
there is live virus still in lens –> significant inflammatory response.
Medulloepithelioma
tumor of the NONpigmented ciliary epithelium (could be benign or malingnat) - most often arises from the ciliary body
has also been seen in the retina and optic nerve
usually seen in kids but can also be found in adults
may have large cysts that can be seen on imaging such as U/S
Rx: observation or enculeation. Surgical resection - may induce metastatic spread or other complications.
Inner portion of the ciliary body
lined by a double layer of epithelial cells - an inner nonpigmented layer and an outer pigmented layer (have an apex to apex arrangement)
Inner nonpigmented layer (think of it like retina) - faces the posterior chamber
while the outer pigmented layer (think of it like RPE) faces the ciliary muscle
Descemet membrane
type IV collagen TRUE basement membrane produced by corneal endothelium. Anterior banded layer posterior NONbanded layer
Acanthameoba stains
Gridley stain: see cysts within a corneal stroma that stains light green.
Other classic stains: calcofluor white and acridine orange
Sometimes: Giemsa/PAS stain
confocal microscopy
nonnutrient agar with e. coli or e. aerogenes
fungi stain
Gomori methanamine silver: fungi stain a darker, silvery color.
Staining band keratopathy
von Kossa stain - stains calcium black
Alizarin red - highlights calcium
Bullous keratopathy
loss of endothelial cells. Space b/t K epi and bowman’s = bulla.
Redundant basement membrane
Redundant basement membrane (darker pink/purple within epi) within the epithelium 2/2 prior episodes of bullous keratopathy. Epi cells encased in basement membrane. Degenerating epi cells within a circular structure made of basement membrane
