ophthalmology

Question 1

Anatomy of layers of the eye

Answer 1

Outer layer: fibrous - made of sclera and cornea
Middle later: uvea
- iris (pupil dilator)
- ciliary body (controls iris, shape of lens, secretion of aqueous humour)
- choroid (nutrition and gas exchange)
Inner layer: retina - macula, optic disc, retina

Question 2

What is anterior uveitis?

Answer 2

Inflammation of the anterior uvea - iris and ciliary body

Question 3

Causes of anterior uveitis?

Answer 3

Autoimmune (majority) - seronegative spondyloathropathies (HLA B27 associated), IBD, sarcoidosis, Behcets
Infection
trauma
Ischaemia
Malignancy

Question 4

Pathophsiology of anterior uveitis?

Answer 4

Anterior chamber is infiltrated by neutrophils, lymphocytes and macrophages
Hypopyon forms - fluid collection containing inflammatory cells at the bottom of the anterior chamber

Question 5

Presentation (symptoms) of anterior uveitis?

Answer 5

Painful red eye (dull, aching)
Reduced visual acuity
Photophobia
Excessive lacrimation

Question 6

Why is there photophobia in anterior uveitis?

Answer 6

Due to ciliary muscle spasm

Question 7

What is seen on examination in anterior uveitis?

Answer 7

Ciliary flush - ring of red spreading from the cornea outward
Miosis - constricted pupil
Abnormally shaped pupil
Hypopyon

Question 8

Why is there miosis in anterior uveitis?

Answer 8

Due to sphincter muscle contraction

Question 9

Why is there an abnormally shaped pupil in anterior uveitis?

Answer 9

Due to posterior synechiae (adhesions) pulling iris into abnormal shapes

Question 10

Management of anterior uveitis?

Answer 10

Steroids (dexamethasone 0.1%) - oral, eye drops or IV
Cycloplegics (cyclopentolate or atropine drops)
If recurrent - DMARDs, anti-TNF

Question 11

How do cycloplegics work in anterior uveitis?

Answer 11

Cycloplegic drugs paralyse the ciliary muscle
They are anti-muscarinic and reduce the action of the iris sphincter muscle and ciliary muscle
They dilate the pupil and reduce pain

Question 12

What are cataracts?

Answer 12

Progressively opaque eye lens, which reduces the light entering the eye and visual acuity

Question 13

What holds the lens in place?

Answer 13

Suspensory ligaments attached to the ciliary body

Question 14

How does the contraction and relaxation of the ciliary body affect the lens?

Answer 14

Contraction - releases tension of ligaments and the lens thickens
Relaxation - ligaments tense and the lens narrows

Question 15

How is the lens supplied?

Answer 15

No blood supply - nourished by aqueous humour

Question 16

When do congenital cataracts occur and how are they tested for?

Answer 16

Occur before birth
Tested by red reflex

Question 17

Risk factors for cataracts?

Answer 17

Increasing age
Smoking
Alcohol
Diabetes
Steroids
Hypercalcaemia

Question 18

Presentation of cataracts?

Answer 18

Asymmetrical
Slow reduction in visual acuity
Progressive blurring of vision
Colours are more faded, brown or yellow
Starbursts arounds lights at night

Question 19

What is seen on ophthalmoscopy in cataracts?

Answer 19

Loss of red reflex
Grey or white lens

Question 20

Management of cataracts?

Answer 20

Cataract surgery

Question 21

What is involved in cataract surgery?

Answer 21

Drilling and breaking lens to pieces, removing pieces and implanting artificial lens

Question 22

Rare but serious complication of cataract surgery?

Answer 22

Endophthalmitis - inflammation of inner contents of eye
can lead to vision loss
Treatment is intravitreal antibiotics