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OPT 203 Ocular Disease > Cornea Part 2 > Flashcards

Cornea Part 2 Flashcards

1
Q

Describe corneal guttate

A

Irregular warts or excrescences on the descemet’s membrane

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2
Q

Describe bullae

A

Blister of serous fluid that can rupture and cause infection (very painful). Associated with Fuch’s syndrome.

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3
Q

What is the name for abnormally weak attachment between the epithelium and bowman’s membrane? When the epithelium can easily become detached eg. because of movement of the eyelids

A

Recurrent corneal epithelial erosion

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4
Q

What are the symptoms of recurrent corneal epithelial erosion?

A 
Severe pain (especially middle of the night / when waking up)
Photophobia 
Red eye (hyperaemia)
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5
Q

What could cause recurrent corneal epithelial erosion?

A

Previous injury / trauma
Corneal dystrophy

Epithelium could then become easily detached eg. By eyelids
Surrounding area then has poor wet ability

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6
Q

Signs of recurrent corneal epithelial erosion ?

A

Epithelial defect
Fluorescein pooling around area of previous defect
Occasionally micro cysts, punctate / fingerprint opacities seen after the defect has healed

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7
Q

Location / laterality of corneal dystrophies vs degenerations?

A

Dystrophy typically central and bilateral and symmetrical

Degeneration typically peripheral and often unilateral and asymmetrical

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8
Q

Onset age of corneal degenerations / dystrophies?

A

Dystrophies 1st to 2nd decade

Degeneration around 5th decade or later

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9
Q

Vascularisation in dystrophy vs degeneration?

A

None in dystrophy, common in degeneration

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10
Q

Family history links between corneal dystrophies vs degenerations?

A

Common links with dystrophies, uncommon with degenerations

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11
Q

Define corneal degeneration

A

Corneal tissue changes that can cause deterioration or impairment of vision - often associated with aging or systemic diseases

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12
Q

Difference between involutional and non-involutional

A

Involutional = associated with ageing and common

Non-involutional = associated with systemic conditions and less common

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13
Q

Some examples of corneal degenerations?

A

Arcus
Vogts limbal girdle
Lipid keratopathy
Band keratopathy

Keratopathy = non-inflammatory corneal disease

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14
Q

Describe Vogt Limbal Girdle

A

Crescent limbal bands that happen at 3 and/or 9 o’clock

Asymptomatic with no known aetiology

Two types:
Type 1 = Swiss cheese hole pattern distinct from the limbus

Type 2= (most common) solid opacification area with no clear limbal zone

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15
Q

Describe lipid keratopathy

A

Lipid deposits in the stroma

Causes:
Age related changes
Secondary to anterior uveitis, chronic corneal oedema, chronic keratitis, silicone oil in anterior chamber
Hereditary
Rare metabolic disorder: metastatic calcification

Primary: (rare) spontaneous occurrence of crystallised lipids in the stroma, no vascularisation

Secondary: (common) secondary to corneal disease with vascularisation eg. HSK or HZK

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16
Q

Describe band keratopathy

A

Age related deposition of calcium salts in the bowmans later, epithelial basement membrane and anterior stroma

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17
Q

Aetiology of band keratopathy?

A

Age related changes

Secondary to anterior uveitis, silicone oil in anterior chamber, chronic corneal oedema, chronic keratitis

Hereditary

Rare metabolic disorder: metastatic calcification

18
Q

Signs and symptoms of band keratopathy

A

Calcified plaque of opacification

Clear margins between limbus and edge of band

Gradual spread of band / plaque

Advanced lesions can become nodular

Symptoms: reduction in vision

19
Q

Describe Francois central cloudy dystrophy and crocodile shagreen

A

NOT dystrophies, are actually both degenerations

Almost distinguishable from each other

Asymptomatic and signs are:
Central greyish polygonal or rounded stroma opacities
No treatment.

20
Q

How would we manage degenerations?

A

Optom - monitor and manage underlying causes
Only treat if affecting vision or causing discomfort

Refer to GP for underlying systemic causes and ophthalmologist is vision impaired.

Treatment may include scrapping / lasers treatment
Keratoplasty in extreme cases

21
Q

Describe arcus (what is it?)

A

Peripheral corneal opacity due to lipid deposits in peripheral cornea
Most common corneal opacity

Asymptomatic

22
Q

Describe the visible signs of arcus

A

Stromal lipid deposits:

  • superior then inferior, creates a band around cornea
  • central border is diffuse then peripheral border is sharp with a distinct edge from the limbus
23
Q

Associations with arcus?

A

Aging

Dyslipidaemia (younger px’s)

24
Q

Generally describe corneal dystrophies

A

A group of corneal opacifying disorders that can affect one or more of the corneal layers

Mostly inherited rare group of disorders
Not associated with systemic disease
Can cause significant sight loss
Slow progressing

25
Q

Examples of corneal dystrophies?

A

Cogan dystrophy
Reis-buckler corneal dystrophy
Granular corneal dystrophy
Fuchs dystrophy

26
Q

Describe Cogan epithelial basement membrane dystrophy

A 
Recurrent epithelial erosions / lesions 
Eg map, dot, fingerprint dystrophy 
Most common corneal dystrophy 
Mostly sporadic 
Bilateral and asymmetrical 
Often no symptoms
27
Q

Describe Reis-Bucklers corneal dystrophy

A

Bowmans later dystrophy
Sub epithelial opacities that are denser in the centre

Can cause recurrent erosion in childhood and vision impairment

28
Q

Describe granular corneal dystrophy

A

Classic central stromal granular dystrophy
Severe appearance
Discrete white central anterior stromal opacities that increase in number and size

Causing blurring of vision and glare / photophobia

29
Q

Describe Fuch’s endothelial corneal dystrophy

A

Bilateral acceleration of endothelial cell loss

Mostly sporadic
Associated with open angle glaucoma

Corneal guttata 
Interruption to endothelial mosaic 
Stromal oedema 
Bullae 
Peripheral vascularisation
30
Q

How would we manage dystrophies?

A

Monitor and only treat if affecting vision or causing discomfort.
Manage symptoms eg irritation with lubrication

Treatment if necessary (ophthalmologist)
Excimer laser
Keratoplasty

31
Q

Define ectasias

A

A group of abnormalities that cause irregularities in corneal shape
Normally progressive and reduce vision

32
Q

Examples of ectasias?

A

Keratoconus
Keratoglobus
Pellucid marginal degeneration

33
Q

Describe keratoconus

A

A progressive corneal disorder with peripheral and central corneal thinning together with asymmetrical astigmatism and the development of an atypical protrusion (come shape)

34
Q

Aetiology of keratoconus?

A

Spontaneous

Secondary to some other systemic conditions

Associations:
Down’s syndrome, marfans, retinitis pigmentosa, vernal keratoconjunctivitis

35
Q

Signs of keratoconus?

A

Increasing asymmetric astigmatism
Scissoring reflex in ret
Vogt striae (deep stromal stress lines)
Cone configuration
Munsen’s sign (lower lid bulges when looking down
Flieshers ring (iron deposits round base of cornea)
Acute hydrops (rupture of stressed descemets membrane)
Steep k readings
Asymmetrical displaced apex seen during topography
Oil drop reflex in ophthalmoscopy

36
Q

How would you manage keratoconus?

A

Manage the rx with spectacles, soft and rgp specialist lenses
Routine referral
Stop rubbing eyes

Referral-
Intracorneal ring
Corneal cross linking
Keratoplasty

37
Q

Describe pellucid marginal degeneration

A

Progressive peripheral corneal thinning disorder often misdiagnosed with keratoconus
Normally bilateral

38
Q

Signs of pellucid marginal degeneration

A 
Bilateral thinning of inferior cornea
Cornea above the thinned area is flat 
Pinhole va is unaffected 
Does NOT show:
- Vogt straie
- acute hydrops 
- fleischers ring
39
Q

Management of pmd

A

Manage rx with specs, specialist cls

Routine referral

Surgical intervention as last resort

40
Q

Describe abnormalities of the cornea and globe

A

Generally congenital birth defects that have resulted in malformed cornea. Can affect clarity or refractive power of cornea

41
Q

Examples of abnormalities of cornea and globe

A 
Microcornea
Microophthalmos
Nanophthalmos
Anophthalmos
Megacornea
Sclerocornea 
Cornea Plano 
Keratectasia 
Posterior keratoconus
42
Q

How would we manage abnormalities of the cornea and globe?

A

As they are congenital usually the hospital will manage (if required)

OPT 203 Ocular Disease (2 decks)

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