Opthalmology

Question 1

Presentation of posterior vitreous detachment

Answer 1

• Painless
• Sudden appearance of floaters- in temporal field
• Normal visual activity
• Flashing lights

Question 2

Presentation of Primary Open Angle Glaucoma

Answer 2

Trabecullar meshwork as resistance to aqueous outflow

Risk factors include older age, afro-carribean population, family history, myopia (near-sightedness).

Those with positive family history of glaucoma (1st degree relative) should be screened annually from aged 40 years

• Usually asymptomatic
• Can cause peripheral vision loss
• Decreased visual acuity
• Optic disc cupping- cup:disc >0.7

Question 3

Management of Primary Open Angle Glaucoma

Answer 3

• 1st line- Latanoprost (prostaglandin analogue) eye drops- increases uveoscleral outflow of aqueous humor from the anterior chamber.
  
  • Side effects: eyelash growth, brown pigmentation of iris
• 2nd line- Beta blockers (timolol) OR Carbonic anydrase inhibitors (dorzolamide) OR sympathomimetic (e.g. brimonidine- alpha 2 adrenoreceptor agonist)- both reduce aqueous production

Surgery or laser treatment for advanced/refractory cases e.g. trabeculectomy- make new channel for aqueous humour to drain away from the eye

Question 4

Presentation of Acute Angle Closure Glaucoma (AACG)

Answer 4

Abrupt increase in intraocular pressure due to impairment of aqueous humour outflow. Opthalmology emergency

Presentation:

• Severe pain
• Haloes around lights with nausea and vomiting
• Pupil is fixed, non-reactive, semi-dilated
• Decreased visual acuity
• Hazy/dull cornea due to corneal oedema

Question 5

Management of Acute Angle Closure Glaucoma (AACG)

Answer 5

Sight threatening ophthalmic emergency requires urgent referral to hospital

Combination of eyedrops + IV acetazolamide

Eyedrops:

• Pilocarpine (direct parasympathomimetic)- causes contraction of ciliary muscle→ increased outflow of aqueous humour
  
  • PiloCarpine- Constrict the pupil- open up the angle
• Timolol (beta-blocker)- decreases aqueous humour production

IV acetazolamide- reduces aqueous secretions

Surgical management- laser iridotomy, makes hole in iris and allows humour to drain (definitive treatment)

Question 6

Classification of diabetic retinopathy

Answer 6

MOST PATIENTS ARE ASYMPTOMATIC/ normal visual acuity

• Non-proliferative
  
  • Mild- microaneurysms
  • Moderate- microaneurysms, blot haemorrahges, hard exudates (deposits of lipids in the retina), cotton wool spots (soft exudates), venous beading
  • Severe- blot haemorrhages and microaneurysms in 4 quadrants, venous beading in 2, intraretinal microvascular abnormality (IMRA) in any quadrant- dilated and tortuous capillaries in the retina
• Proliferative
  
  • Retinal neovascularisation which can lead to vitreous haemorrhage (bleeding into the vitreous humour)
• Diabetic maculopathy- more common in T2DM
  
  • Based on location. Hard exudates and other “background changes” on the macula

Question 7

Management of diabetic retinopathy

Answer 7

Optimise glycaemic control, blood pressure and hyperlipidaemia

Regular review by opthalmology

• Panretinal laser photocoagulation
• Intravitreal VEGF inhibitors
• Vitreoretinal surgery for severe or vitreous haemorrhage

Question 8

Presentation of Age-Related Macular Degeneration (ARMD)

Answer 8

Age-Related Macular Degeneration- UK most common cause of blindness

Degenration of photoreceptors→ drusen (yellow deposits of proteins and lipids), seen on fundoscopy

Dry (90%)- known as atrophic. due to waste products building up between retina and choroid. Characterised by drusen

Wet (10%)- development of new vessels breaking up into the retinal layers, vessels are leaky → odema → rapid loss of vision. Worse prognosis

• Gradually worsening central visual field loss (wet-more acute)
• Gradual reduced visual acuity
• Distortion of line perception

Question 9

Management of Dry and Wet ARMD

Answer 9

• Dry- observation with risk factor modification (stop smoking), and nutritional supplemtnation (vitamins)
• Wet- anti-VEGF injection (ranbizumab), photocoagulation, phototherapy

Question 10

Presentation of scleritis and episcleritis

Answer 10

Rheumatoid arthritis can manifest with episcleritis (erythema, no pain), keratitis, and scleritis (erythema and pain)

• Episcleritis- inflammation of the episclera (outermost layer of the sclera). typically not painful, patches of redness. self-limiting
• Scleritis- inflammation of full thickness of the sclera. more serious than episcleritis. PAINFUL- red eye, watering, photophoboa, reduced visual acuity

Question 11

Presentation, causes, treatment of keratitis

Answer 11

Inflammation of the cornea

• Viral- herpes simplex virus-1 (most common cause). dendritic ulcer with terminal bulbs on fluorescein staining
• Bacterial- pseudomonas, staphylococcus aureus. acanthaemoeba (protozoa, swimming pool, contact lenses)
• Fungal

Presentation

• Painful red eye
• Photophobia
• Foreign body sensation/gritty

Management:

• Virus
  
  • HSV-1- topical ganciclovir (aciclovir) drops followed by topical steroid eye drops
• Bacterial:
  
  • Stop using contact lenses until symptoms have fully resolved
  • Topical antibiotics
  • Cycloplegic for pain relief e.g. cyclopentolate