Opthalmology Flashcards

1
Q

Learning objectives

A

Answer

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2
Q

Define cataracts

A

• Opacification of the lens of the eye

Explain the aetiology/risk factors of cataracts
• Most are IDIOPATHIC (age-related)
• Secondary Causes
o Local: previous eye trauma, uveitis
o Systemic: diabetes, metabolic (e.g. Wilson’s disease), skin disease (e.g. scleroderma), drugs (e.g. steroids)
o Congenital: congenital rubella syndrome

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3
Q

Summarise the epidemiology of cataracts

A

• Major cause of treatable blindness worldwide

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4
Q

Recognise the presenting symptoms of cataracts

A
  • Gradual-onset painless loss of vision
  • Glare from bright light
  • Vision may worsen in bright light
  • Some may experience monocular diplopia with haloes around lights
  • Some may begin to be able to read without glasses (a sclerotic cataract may increase the lens’ converging power)
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5
Q

Recognise the signs of cataracts on physical examination

A
  • Loss of red reflex
  • Hazy lens appearance
  • Reduced visual acuity
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6
Q

Identify appropriate investigations for cataracts

A

• Usually unnecessary

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7
Q

Define Conjuctivitis

A

Conjunctivitis is a common condition that causes redness and inflammation of the thin layer of tissue that covers the front of the eye (the conjunctiva).

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8
Q

Explain the aetiology / risk factors of conjunctivitis

A
Causes
Viruses
Bacteria
Allergies
A chemical splash in the eye
A foreign object in the eye
In newborns, a blocked tear duct

Risk factors:
Exposure to something for which you have an allergy (allergic conjunctivitis)
Exposure to someone infected with the viral or bacterial form of conjunctivitis
Using contact lenses, especially extended-wear lenses

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9
Q

Summarise the epidemiology of conjunctivitis

A

Affects 2% annually. Viral is most common

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10
Q

Recognise the presenting symptoms of conjunctivitis

A

Infective conjunctivitis
If you have infective conjunctivitis, you may also have:

a burning sensation in your eyes
a feeling of grit in your eyes
a sticky coating on the eyelashes – usually when you first wake up in the morning
an enlarged lymph node (gland) in front of the ear
Allergic conjunctivitis
You may have itchy eyes if you have allergic conjunctivitis.

The pattern of symptoms for allergic conjunctivitis depends on the substance you’re allergic to.

Allergies to pollen (hay fever) occur during certain parts of the year. You can have an allergy to:

tree pollen, released during spring
grass pollen, released during the end of spring and beginning of summer
weed pollen, released any time from early spring to late autumn

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11
Q

Recognise the signs of conjunctivitis on physical examination

A

When symptoms are mild, a diagnosis of viral conjunctivitis can often be made without seeing a doctor, and the condition can be treated at home.

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12
Q

Identify appropriate investigations for conjunctivitis and interpret the results

A

Based on symptoms, microbial culture

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13
Q

Define glaucoma

A

• Optic neuropathy with typical field defect usually associated with ocular hypertension (intra-ocular pressure > 21 mm Hg)

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14
Q

Explain the aetiology/risk factors of glaucoma

A

Primary Causes
o Acute closed-angle glaucoma (ACAG)
o Chronic closed-angle glaucoma
o Primary open-angle glaucoma (POAG)

Secondary Causes
o	Trauma 
o	Uveitis
o	Steroids 
o	Rubeosis iridis (formation of new blood vessels on the surface of the iris)
Congenital
o	Buphthalmos (enlargement of the eye balls)

Pathophysiology of Glaucoma
o Ocular hypertension leads to compression and stretching of the retinal nerve fibres
o This leads to scotomas (partial loss of vision) and visual field defects
o Ocular hypertension is due to reduced outflow of aqueous humour caused by:
• AOAG: Obstruction to the outflow (caused by narrowing of the iridocorneal angle and, hence, narrowing of the canal of Schlemm leading to a rapid and severe rise in IOP)
• POAG: Resistance to the outflow through the trabecular meshwork
• Blockage of trabecular meshwork by blood or inflammatory cells

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15
Q

Summarise the epidemiology of glaucoma

A

• Prevalence:
o 1% in over 40 yrs
o 10% in over 80 yrs
• 3rd most common cause of blindness worldwide

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16
Q

Recognise the presenting symptoms of glaucoma

A
•	ACAG
o	Painful red eye 
o	Vomiting 
o	Impaired vision 
o	Haloes seen around lights 
•	POAG
o	Usually ASYMPTOMATIC
o	Peripheral visual field loss 
•	Congenital
o	Buphthalmos
o	Watering 
o	Cloudy cornea
17
Q

Recognise the signs of glaucoma on physical examination

A

• ACAG

o	Red eye 
o	Hazy cornea 
o	Loss of red reflex 
o	Fixed and dilated pupil
o	Eye is tender and hard on palpation 
o	Cupper optic disc 
o	Visual field defect 
o	Moderated raised intra-ocular pressure 
•	POAG
o	Optic disc may be cupped 

o Usually NO signs

18
Q

Identify appropriate investigations for glaucoma

A

• Goldmann Applanation Tonometry
o Standard method of measuring intra-ocular pressure
o Normal IOP = 15 mm Hg
• Pachymetry
o Using ultrasound or optical scanning to measure central corneal thickness (CCT)
o CCT < 590 mm = higher risk of glaucoma
• Fundoscopy
o Detects pathologically cupped optic disc
• Gonioscopy
o Assess iridocorneal angle
• Perimetry (Visual Field Testing)

19
Q

Define uveitis

A

• Inflammation of the iris and ciliary body

20
Q

Explain the aetiology/risk factors of uveitis

A

• May be caused by infection (e.g. herpes simplex)
• It can occur as a manifestation of systemic inflammatory conditions (e.g. reactive arthritis, ankylosing spondylitis, inflammatory bowel disease, sarcoidosis, Behcet’s disease)
• Sympathetic Ophthalmia
o Inflammation of the contralateral eye weeks/months after penetrating injury
o This is due to recognition of eye antigens in the contralateral eye by T-cells that were activated by the initial penetrating injury to the opposite eye

21
Q

Summarise the epidemiology of uveitis

A

• Uveitis associated with spondyloarthritis is twice as common in MALES as females

22
Q

Recognise the presenting symptoms of uveitis

A
  • Pain due to inflammation
  • Pain during accommodation
  • Photophobia
  • Red eyes
  • Blurred vision
  • Lacrimation
  • Rarely associated with tubulointerstitial nephritis (causing flank pain, haematuria, proteinuria)
23
Q

Recognise the signs of uveitis on physical examination

A
  • Reduced visual acuity
  • Ciliary flush
  • Hypopyon (exudate and inflammatory cells in the inferior angle of the anterior chamber)
  • Small irregular pupil due to adhesions of the iris to the lens
  • Slit Lamp - keratic precipitates (leucocyte deposits on the corneal endothelium)
  • Fundoscopy - exclude retinal detachment
  • Signs of Complications - increased IOP, cataract
  • Signs of underlying aetiology
24
Q

Identify appropriate investigations for uveitis

A

• Investigations for associated systemic conditions (e.g. spondyloarthritides - sacroiliac joint X-ray, HLA-typing)