Disorders Of The Cornea Flashcards
What are the different causes of blurring of vision?
Disruption of the transmission of light
Disturbance in the refraction of lught
What are the diff causes of disturbance in the refraction of light?
Abnormalities of the corneal epithelium and tear film
Abnormaltiies of corneal size, shape, or curvature
What are the causes of disruption in the transmission of light?
Corneal scars
Corneal edema
Corneal deposits
Corneal melt
Corneal tumor
What is the corneal presentation of corneal scars?
Fibrosis and new collagen fibril formation
What are the diff cause sof corneal scars?
Microbial keratitis
Corneal trauma
Exposure keratopathy
Lid margin and lash disorders
Congenital corneal scars
What are the 2 types of lid margin disorders?
Entropion - eyelash directed iNWARD
Ectropion - eyelids directed OUTWARD
What is a type of anterior segment dygensis that presents with cornela leukoma w/ defects in posterior stroma, Descemet’s membrane, corneal endothelium?
Peter’s anomaly
What type of edema is due to pump failure of the endothelium or innermost layer of the cornea?
Corneal edema
What are the clinical presentation of corneal edema?
Blurring of vision, recurrent eye pain, redness, foreign body sensation, and tearing
What are the causes of corneal edema?
Endothelial dystrophy
Surgical trauma
Chronic elevation if IOP (glaucoma)
What are the 2 types of endothelial dystrophy that casues corneal edema?
Congenital hereditary endothelial dystrophy
- congenital bilateral, ground-glass appearance
Fuch’s endothelial dystrophy = >50 yrs, females
What are the causes of corneal deposits?
Corneal dystrophy
Lipid keratopathy
Calcific band keratopathy
Corneal staining
Metabolic disorders
What is the appearance of lipid keratopathy?
Yellow or cream-colored located at the corneal stromal layer
What are the cause of calcific band keratopathy?
Chronic inflammation like anterior uveitis, high serum calcium and dsiorders in PO4 metabolism
What are the substance that deposits at the bowman’s layer of eyes with Calcific Band Keratopathy?
Ca hydroxyapatite at the 3 and 9 oclock area with a Swiss cheese pattern
What are the clinical presentation of Corneal Staining?
Heme deposiiton in the corneal stroma due to blunt eye trauma or bleeding problems w/ high eye pressure
Central golden brown to yellow discoid opacity on the cornea
What are the causes of Corneal melt?
Vitamin A deficiency
Alkali chemical burns
What are the clinical presentations of Vit A deficiency leading to corneal melth?
Xerophthalmia
Xerosis (dry conjunctiva)
Bitot’s spots
Corneal ulcers and scars
What are the causes of corneal tumors?
Dermoid choristoma
Corneal intraepithelial neoplasia
Pterygium
What are the clinical presentations of Demoid Choristoma?
Congenital lesion that is smooth, elevated, fleshy colored, oval to round solid mass on top of the cornea and sclera
Dermoids - fibrous tissue and hair w/ sebaceous gland
What are the clinical presentations of Corneal Intraepithelial neoplasia?
translucent, frosted, epithelial sheet starting from the limbus extending to the cornea with fimbriated or scalloped borders and pseudopodia=like exntesions
What virus causes Corneal intraepithelial neoplasia?
HPV
What is the clinical presentation of Pterygium?
Triangular or wing-shaped fold
Benign conjunctival lesion behaves malignantly
What should be checked if there area abnormalities in the corneal epithelium and tear film?
Presence of cracks, smudges
(Should be smooth)
What are the clinical presentation of Dry eye syndrome?
Keratoconjunctivitis sicca (dryness, foreign body sensation, burning sensation and BOV)
What is the tx for abnormalities of corneal size, shape, or curvature?
Rigid contact lenses
What are the causes of corneal distortions?
Previous refractive procedures
Astigmatic keratotomies
Peripheral scars
Conjunctival lesions
