Eye disorders Flashcards
what is a chalazion
benign, self-limiting focal granulomatous swelling of the sebaceous glands without necrosis
presentation of a chalazion
chronic slow-growing firm rubbery nodule on the eyelid causing heaviness
how do you get a chalazion
obstruction of the meibomian glands
due to:
poor eyelid hygiene
stress
immunodeficiency
TB
rosacea
seborrheic dermatitis
what is a hordeolum
stye caused by acute inflammation of the eyelash follicles at the zeis or meibomian glands
how does a hordeolum typically present
painful erythematous tender pus-filled nodule with subsequent spontaneous perforation and purulent discharge
what causes a hordeolum
S. aureus
acne Vulgaris
DM
what is a pinguecula
small yellowish submucosal elevation due to protein and lipid deposits that do not invade the cornea
what is a pterygium
fan-shaped fibrovascular connective tissue that migrates into the cornea but doesn’t cover the pupil
how do pterygiums normally present
as mild astigmatism
highest risk factor for pingueculas and pterygiums
chronic sun exposure
what is keratoconus
non-inflammatory corneal condition that thins the cornea into a cone shape, causing it to bulge forward
how does keratoconus present
altered refractive surfaces
astigmatism
what is a complication of keratoconus
corneal hydrops
rupture of the descemet membrane, allowing the aqueous humor to gain access to the corneal stroma
what are cataracts and how do they present
clouding of the lens, causing light distortion, visual impairment, glaring and opacities within the red reflex
congenital causes of cataracts
hereditary congenital cataracts
galactosemia
congenital infections
acquires causes cataracts
age-related nucleus sclerosis- opacification of the lens nucleus
DM
prolonged glucocorticoid use
trauma
excessive sunlight
smoking
Wilson disease
Down syndrome
what is age-related macular degeneration and what causes it
painless central impairment and blind spots caused by progressive degenerative changes in the macula of the retina
what is the difference in wet and dry age-related macular degeneration
dry:
nonexudative, retinal pigment epithelium atrophy or hypertrophy with deposition of yellow-whitish material in and under the retinal pigment epithelium
wet:
exudative grey/green retinal discoloration with serous detachment of the retina and the retinal pigment epithelium
shows choroidal neovascularization between the retinal pigment epithelium and Brusch’s membrane
presentation of optic neuritis
impair vision with retrobulbar pain worse on eye movement
diagnostics and associations of optic neuritis
Diagnostics: the presence of poorly defined papilla, hyperemia, hemorrhage at the border of the papilla
Associations: MS, syphilis
what is sympathetic ophthalmia and how does it present
bilateral granulomatous panuveitis usually occurring after unilateral penetrating injury
floating spots, reduced injury, pain in both eyes, increased sensitivity to light
explain the pathogenesis of sympathetic ophthalmia and its morphology
T cell-mediated autoimmune response to retinal pathogens
usually absent plasma cells, but may have eosinophils in the infiltrate
cats’s eye pupil (leukocoria)
strabismus
progressive sudden loss of vision in children
retinoblastoma
morphology of retinoblastoma
small blue cells with scant cytoplasm
Flexner-Wintersteiner rosettes and fleurette necrosis with a viable tumor around blood vessels
dystrophic calcification