Corneal Dystrophies

Question 1

What is PPMD

Answer 1

Rare corneal endothelial dystrophy that occurs at birth or during the first decade of life (AD); however most patients with PPMD are not dx with the condition untitled the ages of 30-50 because PPMD is typically slowly progressive or non progressive, and most patients are asymptomatic

Question 2

Corneal epithelial dystrophies

Answer 2

RB (honeycomb)
EBMD (Map dot, negative stain)
MEesmans (100s of intraepithelial cysts)

RCE risk-pain in the AM

Question 3

Corneal stromal dystrophies

Answer 3

Macular (Mucopolysaccharides, gray, decreased VA)
granular (hyaline, breadcrumb, decreased VA)
Lattice (amyloid, linear gray, decreased VA)
Schnyder (cholesterol)

Decreased VA=PTK

Question 4

Corneal endothelial dystrophies

Answer 4

Fuchs: guttata, stromal edema, painful bullae
PPMD: vesicles, train tracks, epi-like endo, secondary angle closure

Question 5

What endothelial cell count can result in corneal stromal edema

Answer 5

Less than 500 cells/mm2

NAK-ATPase pumps cannot maintain proper osmotic balance
Complained of blurred vision worse in the AM

Question 6

Late stages of fuchs

Answer 6

Progression of corneal stromal edema into the epithelium, resulting in vesicles or bullae (bullous keratopathy), that may rupture, leading to pain and scarring

Question 7

What is considered a normal endothelial cell count

Answer 7

2500

Question 8

What is the most common symptom in patietns with PPMD

Answer 8

Decreased vision due to corneal edmea

Question 9

When there is pain in fuchs, what does this mean

Answer 9

There is edema in the stroma or the epithelium, this is where the corneal nerves are

Question 10

Difference between IK and DK

Answer 10

IK has neo

DK has no neo, from herpes

Question 11

What is disciform keratitis

Answer 11

Disc shaped stromal edema. It is most commonly found in HSK

• immune response against the live virus or viral antigen within the corneal endothelium results in inflammation of the endothelium, with resulting, focal, disc shaped edema over the area of involved endothelium
• the condition also presents with endothelial keratin precipitates (KPs) under the area of stromal edema, and mild to moderate iritis
• diffuse corneal scarring and severe vision loss may occur if the condition is not treated in an appropriate and timely manner

Question 12

What is macular dystrophy

Answer 12

AR corneal stromal dystrophy that occurs within the firms decade of life. It is the least common, but most severe of the stromal dystrophies and results in decreased vision earlier in life. Characterized by diffuse, superficial, central stromal haze with Mucopolysaccharides deposits (seen as irregular gray white spots in the cornea) and stromal thinning. Severe vision loss occurs by the age of 20-30; patients may also complain of pain due to RCE (less common)

Question 13

What is IK

Answer 13

Stromal inflammation without primary invovlemt of the corneal epithelium or endothelium. Most patients are born with the condition as a result of congenital syphilis, although it often undiagnosed until the ages of 5-25. It may also occur secondary to herpes simplex and TB

• acute: salmon patch lesion, stromal edema, KPs, and AC reaction ,and conjunctival injection
• chronic: stromal scarring, ghost vessels, irregular astigmatism, and reduced vision

Question 14

What is the only corneal dystrophy with an AR inheritance

Answer 14

Macular

Question 15

Triad of congenital syphilis

Answer 15

1. IK
2. Hutchinson Teeth
3. Deafness

Saddle nose deformity, frontal bossing, saber shins, and “salt and pepper” fundus.

Question 16

Tertiary syphilis findings

Answer 16

Neuro findings: papilledema, unilateral disc edema, optic neuritis, and argyll Robertson pupil

Question 17

Treatment for PPMD and fuchs

Answer 17

Mauro 128 QID, ointment qhs
Hair dryer 5-10m qam
Ocular hypotensive if elevated IOP to minimize corneal edema
Topical abx for ruptured corneal bullae (treated as abrasion)
Significant pain or vision loss resources corneal transplant (PK or DSEK)

Question 18

What should patients with PPMD be monitored closely for

Answer 18

Angle closure glaucoma. Gonio should be performed regularly

Question 19

Difference between DSEK and DMEK

Answer 19

DMEK has no donor stroma

DSEK just removes endo/descemets

Question 20

Cataract surgery and decreased endothelial cell count

Answer 20

Cat sx can increase endothelial cell loss and exacerbate fuchs endothelial dystrophy, especially at endothelial cell counts less than 1000 cells/mm2; patients should have realistic expectations regarding the visual prognosis and potential need for a corneal transplant if cataract surgery is considered

Question 21

What is Dua’s layer

Answer 21

Located between the posterior stroma and descemets membrane. Understanding this may help with endothelial dystrophies and improving the outcomes of corneal surgeries

Question 22

Treatment for disciform keratitis

Answer 22

Pred forte QID
Prophylactic treatment with Zirgan or viroptic (to avoid secondary HSK due to treatment with the steroid)

The initial dose of the steroid depends on the severity of the DK. The dosage of viroptic should be at least the frequency as the dosage of the steroids (pred forte and viroptic both QID)

The steroid should not be tapered until the improvement in VA and/or stromal opacification stabilizes.

Question 23

Treatment for macular stromal dystrophy

Answer 23

Corneal transplant or PTK, usually required in the 3rd decade of life when the patient begins to develop severe vision loss. Recurrence after keratoplasty is uncommon

Question 24

Treatment of IK

Answer 24

Active cases are treated with steroids (pred forte Q2-4H, followed by taper). If patient also has uveitits, use cycloplegic as wells (cyclopentolate 1% QID) should also be prescribed.

Inactive IK that has lead to diffuse stromal opacification may be treated with a corneal transplant. Patients should be evaluated and referred for any underlying systemic etiology

Question 25

Ocular side effects of chlorpromazine (any “azine”)

Answer 25

Pigment on the

• endothelium
• lens
• retina

Question 26

Ocular effects of isotretinoin (accutane)

Answer 26

Blepharoconjunctivitis 
DED
Eyelid edema
Pseudotumor cerebri 
Cataracts
Loss of color vision 
Nyctalopia

Question 27

Ocualr effects of amiodarone

Answer 27

Vortex keratopathy within corneal epithelium
Anterior subcapsular lens deposits
NAION

The corneal epi changes are reversible within 7 months of DCing the medication

Question 28

Ocualr effects of brompheniramine

Answer 28

Antihistamine

Anticholinergic effects

• mydriasis
• decreased lacrimation (DED)
• increased IOP