Cornea Flashcards
(23 cards)
What r examples of type I, II, III, and IV hypersentivities? What is mechanism of each?
I: anaphylactic or atopic
- allergic conjunctivitis
II: cytotoxic
- Foreign ag –> complement
- OCP
III: immune complex
- SJS
IV: delayed hyper
- pre sensitized immune cells
- allergic contact dermatitis
Child with recurrent dendrites
Tyrosinemia
Defect in tyrosine aminotransferase
Autosomal recessive
Restrict dietary tyrosine and phenylalanine (to decrease retardation)
Limbus definitions:
Anatomist
Pathologist
Surgeon
Anatomist- termination of descemets and bowmans
Pathologist-
- anterior limbus= termin of bowman and descemets
- posterior = line btw iris root and schlemms canal
Surgeon
- anterior blue zone (1 mm) and posterior white zone
- perpendicular incision thru conj insertion enters AC thru desc
- perpendicular incision thru posterior aspect of limbus enters AC thru TM
HEDS
Tx of stromal HSV keratitis?
Topical trifluridine and topic steroid
- -adding oral acyclovir to this did NOT help
- -anti viral used to prevent epithelial HSV
What is epi LASIK?
Blunt microkeratome to remove epithelium then ablate stromal bed. Plane of separation btw bowmans and basement membrane
What is LASEK?
Put alcohol on epithelium to remove it then laser bed. Then replace epithelium
What findings make dx of ppmd?
How does it differ from ICE?
What % get glaucoma?
AD Cluster or linear vesicles in posterior cornea surrounded by gray haze. Iris atrophy Corectopia Iridocorneal adhesions
Differs: ppmd bilateral, ICE uni
Glaucoma 15% in ppmd
What r cutoffs for post op power of cornea after LASIK?
How do u predict postop power?
Keep between 34 and 50D
If correcting myopia remove 0.8 D for every D of ablation
For hyperopia it’s 1D increase for every D of treatment
Diff etiologies of dry eye syndromes and examples
Aqueous deficiency -lac gland dysfunction, infiltration (tumor), anti histamine, inflammation (sjogren) Lipid def -blepharitis, rosacea Mucin def -goblet cell dysfunction -OCP, SJS, vit a def, alkali burn
Most common muscle affected by thyroid eye disease
Inf rectus
Spare tendon
IMSLO - Most to least common
Inf rec, med, sup rec, lat then obliques
Mimics position of BCC
-lower lid then med canthus, upper lid then lay canthup
What determines prognosis of orbital lymphoma?
Location
Eyelid worst (67% systemic dz)
Orbit (35%)
Conjunctiva (20%)
Most common benign orbital tumor in adults? Children?
Benign adult- cavernous hemangioma
Benign kids- capillary hemangioma
What is diff btw external and internal hordeolum?
External- Zeiss gland obstructed
Internal- meibomian
What bacteria assoc w angular blepharitis
Moraxella
Multiple Sebaceous tumors and keratoacanthomas
What else might the pt have?
Visceral tumors (esp GI)
Muir-torre syndrome
Phlyctenule -
What’s the mechanism?
What is most common etiology?
What r others?
Type 4 hyper sens
Staph= most
TB is classic
Also hsv candida coccidiomycosis, LGV (chlamydia)
At what age do atopic keratoconjunctivitis pt present?
What r other eye associations?
30-50 yr
Keratoconus, pellucid marg
Subscapsular cats (Maltese cross)
Bilateral hsv keratitis
If u see pt w fbs and staining of superior limbus, what testing should u get?
What’s treatment?
SLK Assoc w thyroid dysfunction in 50% Females 30-55 yr Tx: nor steroids -bcl, pressure patch, silver nitrate, cauterize
Which strains assoc w EKC?
What about pharyngoconjunctival fever?
EKC- 8, 19, 37
PCF- 3, 4,5,7
Interstitial keratitis ddx?
What if assoc w tinnitus, vertigo or hearing loss?
What’s treatment
Large ddx includes syph (classic), hsv most common, etc
Cogans syndrome
- IK and CN8
- likely autoimmune
- 80% progress to deafness without systemic steroids!!
Woody palpebral conjunctiva
Dx?
What’s defect?
Ligneous conjunctivitis
Type 1 plasminogen deficiency
Tx: excise and use Mmc or amniotic membrane
Corneal stromal dystrophy w highest recurrence rate after PK
Reis buckler then Lattice
Then granular then macular
“rude little green men keep coming back”
Most common of stromal k dystrophy
Gran> lattice > Mac
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