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KMK Ocular Disease > 7 - Cornea1 > Flashcards

7 - Cornea1 Flashcards

1
Q

Dellen

A

= DEHYDRATED STROMA

Area of cornea that wets poorly -> stromal dehydration + corneal thinning -> positive staining/pooling of fluoro

Seen adjacent to areas of elevation (e.g. pterygia)

Asymptomatic or complaints of FBS, other dry eye symp

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2
Q

Exposure keratopathy

  • pathophys
  • signs/symp
A

= EYELID ISSUE

Abnormal or incomplete lid closure:

  • CN7 issue: Bell’s (idiopathic), cerebrovascular accident, aneurysm, MS, HS/ZV, sarcoid
  • orb.oculi issue: surgery causing ectropion, TED, floppy eyelid, #1 NOCTURNAL LAGOPHTHALMOS

Signs: vary from mild SPK (esp INFERIOR 1/3rd) to corneal ulceration, decr corneal sensitivity is common

Symp: redness/FBS/burning that’s WORSE IN THE MORNING

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3
Q

Filamentary keratopathy

  • who
  • pathophys
A

Hx of multiple episodes, chornic symptoms of irritation and dryness

CHRONIC INFLAMMATION of cornea -> oc surf dz
#1 = keratoconj-itis sicca
-others: floppy eyelid, slk, corneal erosion, cls overwear, neurotrophic k

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4
Q

Filamentary keratopathy

-signs/symp

A

Signs: filaments = mucus + degenerated epithelial cells

  • remain attached to corneal surface
  • range from 0.5 to 10mm
  • early = comma-shaped, late = stringy
  • will stain with fluoro

Symp: mild-severe FBS, photophobia, epiphora, blur, blepharospasm

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5
Q

Superficial punctate keratitis

  • pathophys
  • signs/symp
A

Non-specific inflammation of corneal epithelium
-cls wear, corneal infxn, dry eye, blepharitis, etc.

Pinpoint defects in corneal epi - stains with fluoro
-localized, scattered, confluent (severe)
Asymptomatic; blur, irritation, fbs, photophobia, redness, tearing

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6
Q

Thygeson’s superficial punctate keratopathy

  • who
  • pathophys
A

Rare, 2nd-3rd decade, hx of recurrent episodes, no sex predilection

UNKNOWN ETIOLOGY

  • may be viral, autoimmune
  • no known associated condns
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7
Q

Thygeson’s superficial punctate keratopathy

-signs/symp

A

Signs: BILATERAL (90%), small, multiple, asymmetric GRAY-WHITE clusters of superficial INTRAEPITHELIAL raised CENTRAL corneal lesions (“crumb-like” opacities)

  • acute attacks: last 1-2mo, light fluoro staining, exacerbations within 6-8wks
  • remissions: no staining

Symp: FBS, photophobia, tearing, OCCASIONAL BLURRED VISION
-overall, eye is relatively quiet (no ac rxn, conj injection)

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8
Q

3 condns to think of when see intraepithelial corneal defects

A

Thygeson’s
Herpes
Meesman’s

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9
Q

Neurotropic keratopathy

  • who
  • pathophys
A

Past surgical procedures, cls wear, systemic dz, meds

Damage to sensory supply anywhere from trigeminal nucleus to corneal nerve endings -> CN V1 neuropathy -> decr corneal sensitivity + decline in corneal regeneration/wound healing

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10
Q

Neurotropic keratopathy

-common causes

A

Directly affecting V1: HSV, HZV, DM, LASIK
-also RCEs/dystrophies, medications (timolol, betaxolol, diclofenac sodium)

Damage to CN 7 -> impaired reflex tearing -> chronic damage to ocular surf + disruption to V1

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11
Q

Neurotropic keratopathy

-signs/symp

A

Signs: decr corneal sensitivity

  • early: SPK, perilimbal injection
  • late: sterile inferior oval ulcer (-) signs of inflammation

Symp: redness, tearing, decr vision, fbs, swollen eyelids
-CORNEAL FINDINGS&raquo_space;> SYMPTOMS INDICATE

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12
Q

Recurrent corneal erosion

-pathophys

A

POOR HEMIDESMOSOME ATTACHMENTS to underlying basement membrane
2 scenarios: past abrasian (trauma), dystrophy (EBMD)
-incr risk if abrasion results from organic etiology (fingernail, stick)

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13
Q

Recurrent corneal erosion

-signs/symp

A

Signs: abrasion of varied size that stains with fluoro

Symp: recurrent, ACUTE PAIN WORSE IN MORNING UPON WAKENING, lacrimation, photophobia, blur

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14
Q

Thermal/UV keratopathy

  • who
  • pathophys
A

Prolonged skin exposure, welding, skiing/mountaineer, sunlamps

Epithelium + Bowmans absorb <300nm (UVC)
Excessive UVC absorption -> hyperactivation of K+ channels -> loss of intracellular K+ -> cell death

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15
Q

Thermal/UV keratopathy

-signs/symp

A

Signs: confluent SPK - stains with fluoro

Symp: pain, photophobia, blur
-WORSE 6-12hrs AFTER INCIDENT

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16
Q

Dry eye disease

  • definition
  • who is most likely to have it
A

Multifactorial dz of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to ocular surface

Older, menopausal women

17
Q

Dry eye disease causes

-medications

A

Anticholinergic (anti-PNS) effects:

  • STop ACH
  • anti-histamines/psychotics/depressants/anxiety
  • muscle relaxant (cyclobenzaprine)
  • ipratropium (via muscarinic blockade)

Other: isotretinoin, BBs, contraceptives, HRT, ADHD, diuretics

18
Q

Dry eye disease causes

  • sytemic diseases
  • environmental factors
A

Big 4: TED, RA, Sjogren’s, Lupus

Fans, dusty environ, low humidity

19
Q

Dry eye disease

-signs/symp

A

Signs:

  • general: decr TBUT, incr tear osmolarity
  • aqueous deficient: THIN TEAR MENISCUS/LAC LAKE/PRISM (<0.2mm), decr Schirmer + phenol red thread (<10mm in 15sec)
  • evaporative: decr TBUT, poor expression/atrophy of meibomian gland
  • other: conj hyperemia, tear film debris, staining with lissamine green (classically 3/9 o’clock)

Symp: burning, dryness, tearing, itching, blinking, photophobia, cls intolerance, fbs
-WORSE AT THE END OF THE DAY

20
Q

Dry eye disease
-interpretations of:
—Schirmer 1 + 2
—phenol red thread

A

S1 = WITHOUT ANESTHETIC = basal, reflex, emotional secr

  • normal >10mm in 5 min
  • abnorm <5mm in 5 min

S2 = WITH ANESTHETIC = ONLY BASAL (krause, wolfring) secr
-normal >5mm in 5 min

Phenol
-normal >10mm in 15sec

21
Q

Dry eye disease

-primary mechanisms (2)

A

Tear HYPEROSMOLARITY -> inflammatory cascade -> damages ocular surf + releases inflamm mediators into tears

  • normal/avg: 308 mOSm/L
  • dry eye is >308 OR >8 difference between eyes

TF INSTABILITY
-can be secondary to hyperosmolarity or disease process

22
Q

2 divisions of aqueous deficient dry eye

A

Sjogren’s

Non-sjogren’s

23
Q

Primary vs secondary sjogren’s

A

P: dry eye, dry mouth

S: TRIAD - dry eye, dry mouth, autoimmune CT dz

  • RA, SLE, polyarteritis nodosa, wegener’s
  • ACCOUNTS FOR 50% OF DRY EYE CASES!
24
Q

Non-sjogren’s aqueous deficient dry eye

A

Secondary to LACRIMAL GLAND DYSFUNCTION

Primary lac gland deficiency: #1 AGE-RELATED

Secondary lac gland deficiency: ABC

  • attacked gland (sarcoid, lymphoma, aids, graft vs host)
  • blocked gland duct (trachoma, pemphigoid, erythema multiforme, burns)
  • cut nerves (cls wear*, diabetes, bells, drugs, neuro k, surgery)
  • ~50% of cls wearers have dry eye symptoms
25
Q

Evaporative dry eye

-3 main causes

A

MGD
Vit A deficiency
Contact lens wear

26
Q

Evaporative dry eye

-intrinsic causes

A 
Pathology in lid structure/dynamics
#1 MGD
Lid position disorders: ptosis, nocturnal lagophthalmos
Low blink rate: intense concentration, computers, Parkinson’s
-results in poor expression of meibum -> hyperkeratinize -> obstruction -> intraductal htn due to build-up -> duct dilation -> mg atrophy
27
Q

Evaporative dry eye

-extrinsic causes

A

Independent of lid pathology

Oc surf dz: vit A deficiency (xerophthalmia), topical anesthetics/preservatives

Contact lens wear

28
Q

All corneal ectasias can cause

A

Hydrops = splitting of Descemet’s

29
Q

List 3 corneal ectasias

A

Keratoconus
Pellucid marginal degeneration
Keratoglobus

30
Q

Keratoconus

-who

A

Usually sporadic
6-13% of cases are AD
Commonly presents around puberty
53% have hx of atopy

31
Q

Keratoconus

-pathophys

A

Non-inflammatory, progressive, degenerative dz of unknown etiology

Stromal collagen FIBRIL DISPLACEMENT due to loss of adhesion between fibrils -> corneal thinning + protrusion due to degeneration of fibrils by MMPs

Assoc with eye rubbing, atopy, cls wear, ocular condns, systemic condns

  • ocular: allergic (vkc, akc, fes), connective tissue abnorm (fuchs, ppmd, granular, lattice), hereditary (aniridia, rp, lebers, rop, cone dystrophy)
  • systemic: TDOME (turners, downs, oi, marfans, ehlers)
32
Q

Keratoconus

-signs/symp

A

Signs:

  • early: fleischer’s ring (iron), scissors reflex, irregular mires, inferior topography steepening
  • late: vogt’s striae (vert lines in desc, disappear with pressure), muson’s sign, rizzuti’s sign (conical reflection on nasal cornea with temporal lighting), hydrops
  • 53% with mod-severe develop scarring

Symp: progressive decr vision, photophobia, glare, monocular diplopia, ghost images
-acute vision loss + pain if hydrops develops

33
Q

Keratoconus

-mild vs mod vs severe

A

Mild: <48D
Mod: 48-54D
Severe: >54D

34
Q

Pellucid marginal degeneration

  • who
  • pathophys
A

Early adulthood (20-40), no sex predilection

Unknown etiology
Thought that COLLAGEN ABNORMALITIES -> thin, weakened area with crescent-shaped inferior distribution
IOP causes corneal protrusion right above area of thinning (NOT WITHIN area of thinning, as with keratoconus)

35
Q

Pellucid marginal degeneration

-signs/symp

A

No pain
Bilateral, inferior corneal thinning: 4 to 8 o’clock, 1-2mm from limbus
High ATR astig
Topography: “kissing doves” or “crab claws”

36
Q

Keratoglobus

  • who
  • pathophys
  • signs
A

Congenital, AR (tho may be acquired from advanced k-con, trauma, exophthalmos)

Assoc with Ehlers-Danlos, blue sclera, Leber’s congenital amaurosis

Diffuse corneal thinning - concentrated in periphery
Can result in acute corneal edema due to rupture in descemet’s

KMK Ocular Disease (17 decks)

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