Ophthalmology

Question 1

Causes of leukocoria

Answer 1

• Congenital cataract
• Retinoblastoma
• Persistent fetal vasculature
• Coats disease
• Retinopathy of prematurity
• Optic disc abnormalities
• Uveitis
• Toxocariasis
• Coat’s disease
• Norrie disease
• Vitreous hemorrhage
• Hereditary retinal dysplasia
• Astrocytic hamartoma

Question 2

Where is the lesion in a homonymous hemianopia?

Answer 2

• incongruous defects: lesion of optic tract
• congruous defects: lesion of optic radiation or occipital cortex
• macula sparing: lesion of occipital cortex

Question 3

Where is the lesion in a homonymous quadrantanopia?

Answer 3

• superior: lesion of temporal lobe
• inferior: lesion of parietal lobe
• mnemonic = PITS (Parietal-Inferior, Temporal-Superior)

Question 4

Where is the lesion in a bitemporal hemianopia?

Answer 4

• lesion of optic chiasm
• upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour
• lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

Question 5

Extraocular muscle most at risk in orbital floor fracture?

Answer 5

Inferior rectus

Question 6

Causes of corneal opacity

Answer 6

• S - Sclerocornea
• T - Tears in the Descemet membrane (can be due to birth trauma or congenital glaucoma)
• U - Ulcers
• M - Metabolic
• P - Peters anomaly (abnormal development of the anterior segment)
• E - oEdema
• D Dermoid

Question 7

Features of juvenile optic atrophy

Answer 7

• Autosomal dominant inheritance
• Bilateral
• Symptoms start in early childhood
• Severity of the vision loss varies widely between children
• There is reduction in visual acuity, a pale optic disc, loss of color vision, and centrocecal scotomas
• The symptoms occur due to atrophy of ganglion cells in the retina
• There is also associated loss of myelin sheaths in the optic nerve.
• The condition is often progressive
• Irreversible process, but steroids are used to slow progresion

Question 8

Eye features of Down’s

Answer 8

• Watering eyes
• Squint 20%
• Hypermetropia 40%
• Myopia 14%
• Astigmatism 30%
• Nystagmus 10%
• Brushfield spots up to 90%
• Cataracts
• Keratoconus

Question 9

Causes of coloboma

Answer 9

• CHARGE (coloboma, heart anomaly, choanal atresia, restriction of growth/developement, genital anomaly, ear abnormality
• In association with renal abnormalities
• Cat eye syndrome
• DiGeorge syndrome
• Treacher Collins syndrome
• Epidermal naevus syndrome
• Velo-cardiofacial syndrome
• Wolf-Hirschhorn syndrome
• Kabuki syndrome
• Goldenhar syndrome
• MIDAS syndrome (microphthalmia, dermal aplasia, and sclerocornea)
• Trisomy 21, 13, & 18

Question 10

Features of retinoblastoma

Answer 10

• Embryonal tumour of the eye
• Most common under age 3
• Majority are unilateral
• Bilateral disease nearly always has a genetic component
• Most commonly presents with strabismus or leukocoria
• Treatment may be with photocoagulation, cryotherapy, radiotherapy, chemotherapy, or enucleation
• The five-year survival in the UK is currently > 95%

Question 11

What is the Hirschberg test for?

Answer 11

Squint