Cornea

Question 1

interstitial keratitis
presentation:
etiology:
trx:

Answer 1

presentation: non ulcerating inflammation of corneal stromal

– red, painful, photophobic, excessive lacrimation

– unil or bil

–stroma neovascularization
– AC rx : cells/flare

etiology: 2’ to immune rxn caused by exposure to infectious agents that trigger deployment of T-cells to stroma.

– Herpes simplex (unilateral)
– congenital syphilis (most common)
–Lyme disease

trx: IF HERP. SIMPL
– topical steroid q1-6hours
–cyclopegic
– valtrex 1 gram p.o tid

– recovery, the stromal bv become non-perfused or look like ghost vessels

Question 2

congenital syphilis
Hutchinson triad(HID)

Answer 2

interstitial keratitis
peg shaped incisors
deafness

dilated exam: optic atrophy, salt/pepper fundus

interstitial keratitis: inflamm. of cornea cause blurry vision & pain

Question 3

pt w/ interstitial keratitis due to lyme disease

– symptoms :
– definitive diagnostis

Answer 3

– fatigue, HA, fever

DEFINITIVE diagnostic: red rash w/ bull’s eye at site of infection

Question 4

lyme disease trx

Answer 4

oral doxycycline in early lyme disease

Question 5

syphilis trx

Answer 5

IV aqueous crystallin PCN G

Question 6

corneal defect that frequently occurs in response to a previous corneal abrasion due to something organic (fingernail or tree branch)

Answer 6

recurrent corneal abrasion

Question 7

explain RCE

Answer 7

initial abrasion heals but short time after, pt experiences another episode w/o incident.

– happens 1st thing in AM/
-eyelids stick to new unstable epithelium and cause it to tear when eyes open

Question 8

ideal way to treat RCE

Answer 8

erythromycin ointment qid, PF ATs q2hours + BCL
– monitor every 1-2 days until corneal defect healed

hyperosmotic drops or ATS 6-8 weeks post to ensure hemidesmisomes form properly

Question 9

in the event of an RCE, w/ no pt improvement.
clinical exam reveals corneal defect w/ loose epithelium & areas of heaping around edges. What is best course of action? explain procedure

Answer 9

corneal debridement
- anesthetize cornea
- use cellulose sponge & forcepts to remove loose epithelium

Question 10

giving medical advice to pt over the phone requires what 2 actions?

Answer 10

document date, time, and specific instructions (OTC meds recommended to buy)
– call pt in 1-2 days to make sure they got correct product and f/u

Question 11

marginal keratitis/staphylococcal hypersensitivity keratitis
clinical presentation

Answer 11

• sterile marginal infiltrates superior or inferiorly (lid margins rest on corneal surface)
• single or multiple infiltrates concentric to limbus
• local conjunctival hyperemia
• epithelial defects overlying lesion but smaller than infiltrate
• AC usually quiet
• anterior blepharitis (flakes on lashes)

Question 12

pt symptoms for marginal keratitis

etiology

Answer 12

photophobia, pain, localized conjunctival redness, chronic eyelid crusting, fb sensation, ocular dryness

etiology: staphyloccal aureus bacteria on eyelid margins

Question 13

how does clinical presentation of phlyctenule differ from marginal keratitis

Answer 13

corneal phlyctenule is small, white nodule found at the limbus.
- assoc w/ ulceration of corneal epithelium
- lesion can travel to central cornea, leaving corneal scar, neovascularization

Question 14

presentation of bacterial corneal ulcer

Answer 14

• severe redness, pain, photophobia, decreased VA, discharge
• focal white opacity in corneal stroma + epithelial defect that stains with fluorescein

Question 15

corneal dellen symptoms/signs

Answer 15

• mild irritation and fb sensation
• SLE: corneal thinning at limbus adjacent to conjunctival or corneal elevation
• sodium fluorescein pooling in the area

Question 16

thygeson superficial punctate keratitis

Answer 16

chronic bilateral condition
- fb sensation, tearing, photophobia
- macro-punctate gray-white corneal epithelial opacities that are slightly elevated
- stain centrally

Question 17

treatment for marginal keratitis

Answer 17

–address blepharitis: warm compress, eyelid hygiene
-fluoroquinolone antibiotic qid or bacitracin, erythromycin

• mod to severe case: low dose topical steroid: loteprednol 0.2% to 0.5% or prednisolone 0.25% qid or combo such as Tobradex.

DONT USE STEROID ALONE

-add systemic tetracyline (doxycline) if symptoms continue

• topical restasis/cyclosporine for long term control of ocular inflammation

resolves on its own if left alone for several weeks. self limiting

Question 18

hallmark signs of keratoconus

Answer 18

-central/paracentral stromal thinning
- apical corneal protrusion
- irregular astigmatism
- scissor reflex on retinoscopy

SLE: - munson sign- bulging of Lower lid
- iron deposits at base of cone -epithelium -kayser ring
-vertical deep striae in corneal stroma(disappears w/ external pressure)
- rupture of descemet, leading to aqueous into cornea–> hydrop

Question 19

describe keratometry finding for keratoconus

Answer 19

• steep K value >48D or >54D in severe case
• corneal pachy shows progressive corneal thining corresponding to area of conical protrusion

Question 20

difference in clinical presentation & topography of keratoconus and pellucid marginal corneal degeneration

Answer 20

PMD protrudes superior to area of corneal thinning

hallmark sign: kissing birds patten on topography

Question 21

keratoglobus is defined as

Answer 21

corneal thinning over the entire cornea; ectasia is generalized

Question 22

Terrient marginal degeneration

Answer 22

• peripheral corneal thinning or extensive areas of cornea
• degeneration starts superiorly, thin stroma
• anterior stromal opacities
• clear region between opacities and limbus

*note optical section

Question 23

forme fruste keratoconus topography reveals:

Answer 23

topography displays central or paracentral irregular astigmatism
- pt asymptomatic

Question 24

best candidates for corneal CXL

Answer 24

• 35 YO and younger
• moderate keratoconus, max K power <65D
• corneal thickness >400micron
• 20/30 or worse VA

Question 25

standard protocol for corneal CXL requires minimum corneal thickness of ____ after removal of corneal epitheal in order to prevent endothelial damage

Answer 25

standard protocol for corneal CXL requires minimum corneal thickness of 400um after removal of corneal epitheal in order to prevent endothelial damage

Question 26

contraindications to CXL

Answer 26

prior hx of herpetic infections (to avoid viral reactivation) - concurrent infection - severe corneal scarring/opacity - hx of poor wound healing, severe ocular surface disease - hx of autoimmune disorders ## Footnote it pt NEEDS cxl w/ hx of herpetic infections, pre & postoperative prophylactic oral acyclovir can be considered

Question 27

epithelial ingrowth epidemiology:

Answer 27

happens days to weeks post LASIK and seen on flap edge interface. - ingrowth due to proliferation of surface epithelial cells into the corneal flap interface - possibly due to interruption- epithelial cells wont migrate as long as they are surrounded by other epith cells. lasers can disrupt - risk factors: older pt, EBMD, RCE hx, eye rubbers, diabetic pt, LASIK, over manipulation of flap

Question 28

diffuse lamellar keratitis/sands of sahara

Answer 28

2-5 days post LASIK - little to no conj injection - hyperopic shift w/ astigmatism - SLE : diffuse inflammatory infiltrates across periphery of surgical interface but not in stroma or in the flap -central corneal hazy TRX: topical steroids every hour - if infiltrates are severely condensed, flay need to be lifted and interface debrided - stromal melt could happen if not detected & treated early

Question 29

difference between microbial keratisis & diffuse lamellar keratitis

Answer 29

infections cause redness, include some discharge. cant trx infection with steroid pt will note irritation/discomfort

Question 30

treating epithelial ingrowth post LASIK

Answer 30

if epith ingrowth is small and only in periphery of flap: monitor in 2-3 weeks to make sure VA is unchages and ingrowth stays in that location mild ingrowth can spontaneously resolve if change in VA and progression, refer to surgeon to re-lift flap and remove aberrant cells

Question 31

topical ophthalmic meds used 1 week post LASIK

Answer 31

ATs topical steroid gtts topical antibiotic