B1. Corneal Degeneration & Dystrophy

Question 1

what is the difference between dystrophy and degeneration?

Answer 1

dystrophy: A disorder in which an organ or tissue of the body wastes away/weaken
Hereditary condition
NOT due to arrested development
Usually bilateral, only involves central acornea and retina
young onset
no vascularisation

degeneration:
Acquired loss of function associated with
Ageing
Inflammation
Infection
Vascular disease
Vitamin deficiency
Can be any part of the eye, often unilateral
40 or more years old
common vascularisation

Question 2

what are the SSX of band keratopathy? is it a degeneration or a dystrophy? Mx?

Answer 2

degeneration

Symptoms:
Decreased vision (if blocking pupil)
Irritation, pain, FB sensation

Signs:
Early: white granular crescent at limbus
Later: spread centrally to form a band of chalky plaque

Question 2

what are the SSX of crocodile shagreen? is it a degeneration or a dystrophy? any MX?

Answer 2

degeneration

Symptoms:
Asymptomatic

Signs:
Greyish-white polygonal opacities in stroma with clear spaces in between

no Mx

Question 3

MX for band keratopathy?

Answer 3

Lubrication for mild sx
Chelation
Monitor 3-6 mths

Question 4

background and cause for band keratopathy?

Answer 4

Background
Deposition of calcium in Bowman’s membrane

Due to:
Chronic anterior uveitis
Age-related
Systemic hypercalcemia
Hereditary

Question 5

what are the 7 corneal dystrophies? classify the further by which layers of the cornea they affect

Answer 5

Epithelial basement membrane dystrophy (EBMD)
Meesman dystrophy (epithelial)

Reis-Buckler’s dystrophy (bowmans layer)

Granular dystrophy (stromal)
Lattice dystrophy (stromal)
Macular dystrophy (stromal)

Fuch’s dystrophy (endothelial)

Question 6

what is the background and etiology of EBMD?

Answer 6

Background
Seen in 20-30yo, 10% of px recurrent erosions in 30’s

Etiology
Thickening of basement membrane into epithelium with protein deposits -> weak epithelial adhesion -> epithelial erosion

Question 7

SSx of EBMD?

Answer 7

Signs:
Dot-like opacities
Microcysts
Maps
Fingerprints

Symptoms:
May range from no symptoms to irritation, photophobia, reduced VA

Question 8

Mx for EBMD?

Answer 8

Management

Lubricants
Bandage CL
Topical hypertonic saline (5% NaCl)

Question 9

what is the background of meesman dystrophy?

Answer 9

Background
Juvenile epithelial dystrophy
Presents before 2nd birthday

Question 10

SSx of meesman dystrophy?

Answer 10

Signs
Small whitish intraepithelial cysts
Possible epithelial erosions

Symptoms
May range from no symptoms to irritation, photophobia, reduced VA (Same as EBMD)

Question 11

Mx of meesman dystrophy?

Answer 11

Symptomatic relief, lubricants.

Question 12

what is the background of reis-bucklers dystrophy?

Answer 12

Background

Onset is in early infancy
Autosomal dominant

Question 13

SSx of reis bucklers dystrophy?

Answer 13

Hazy white, round, polygonal opacity in Bowman’s, progress to reticular pattern

Severe recurrent corneal erosions in childhood

Question 14

Mx for reis bucklers dystrophy?

Answer 14

Excimer laser keratectomy
Lamellar keratoplasty

Question 15

etiology for all stromal dystrophies?

Answer 15

primarily affects stroma but over time they often extend into the anterior corneal layers and some may affect Descemet’s membrane and the endothelium.

Question 16

What gene type is lattice dystrophy? SSx? Mx?

Answer 16

Classic form - TGFB1 type
autosomal dominant

recurrent erosion occurs at the end of first decade

SSx:
‘glass-like’ filamentous lesions
generalized stromal haze may progressively impair vision

Treatment: penetrating or deep lemallar keratoplasty

Question 17

What gene type is granular dystrophy? SSx? Mx?

Answer 17

Classic form - TGFB1 type
autosomal dominant

recurrent erosion uncommon

SSx
glare and photophobia
Discrete crumb-like opacities are seen in the central anterior stroma
gradual increase in number and size, with deeper and outward spread
corneal sensation impaired

Treatment: penetrating or deep lemallar keratoplasty

Question 18

What gene type is macular dystrophy? SSx? Mx?

Answer 18

gene CHST6, autosomal recessive
early (end of first decade) visual deterioration

recurrent erosion very common

dense greyish-white spots centrally in anterior stoma and peripherally in posterior stroma
eventual involvement of full-thickness stroma

Treatment: penetrating keratoplasty

Question 19

what is the background of fuchs dystrophy?

Answer 19

Slow progressive disease in old age
Usually women are affected
­Bilateral endothelial cell loss­
Increased prevalence of open-angle glaucoma

Question 20

6 SSx of fuchs dystrophy?

Answer 20

Symptoms­

1. Gradually worsening blurring, particularly in the morning due to corneal edema­
2. Onset usually middle age or later

Signs­

3. Cornea guttata – presence of irregular warts on Descemet’s membrane secreted by abnormal endothelial cells­
4. Specular reflection shows tiny dark spots, progressing to “beaten metal” appearance­
5. Endothlial decompensation leading to central stromal edema and blurred vision­
6. Edema in advanced cases forms bullae (bullous keratopathy), rupture of bullae can lead to pain and exposed nerve fibres­

Question 21

Mx for Fuch’s dystrophy?

Answer 21

Non-urgent referral.

hypertonic saline eye drops and/or ointments. Use of the hypertonic saline may stabilize or improve vision by drawing extra water out of the cornea.

Any activity that helps to evaporate fluid off the cornea will help shorten the time to visual recovery. Such activities may include pointing car vents toward the face or blowing air by the eyes using a hair dryer at arm’s length.

Bandage contact lenses can also be quite helpful in management of painful ruptured bullae in more severe disease.

As Fuchs’ dystrophy progresses, medical treatment may fail and surgical management becomes necessary.