Opthalmology Flashcards
Define cataracts.
Opacification of the lens of the eye.
What are the causes of cataracts?
o Idiopathic
o Secondary Causes
- Local = previous eye trauma, uveitis
- Systemic = diabetes, metabolic (e.g. Wilson’s disease), skin disease (e.g. scleroderma), drugs (e.g. steroids)
- Congenital = congenital rubella syndrome
What are the presenting symptoms of cataracts?
o Gradual-onset painless loss of vision
o Glare from bright light
o Vision may worsen in bright light
o Some may experience monocular diplopia with haloes around lights
o Some may begin to be able to read without glasses (a sclerotic cataract may increase the lens’ converging power)
What are the clinical signs of cataracts on examination?
o Loss of red reflex
o Hazy lens appearance
o Reduced visual acuity
What are the appropriate investigations for cataracts?
O None necessary
Define conjunctivitis.
Inflammation of the conjunctiva.
- Associated inflammation of the cornea = keratoconjunctivitis*
- Associated eye lid involvement = blepharoconjunctivitis*
What are the causes of conjunctivitis?
o Infectious = Viral, Bacterial
o Non-Infectious = Allergic, Mechanical/irritative/toxic, Immune-mediated, Neoplastic
What are presenting symptoms of conjunctivitis?
o Red eye (usually generalised and often bilateral)
o Irritation, discomfort and grittiness
o Discharge (may be watery, mucoid, sticky or purulent depending on cause)
o Photophobia (suggest corneal involvement)
o Visual acuity usually unaltered
What are the clinical signs of conjunctivitis on examination?
o Conjunctival injection (i.e. blood shot eyes)
o Dilated conjunctival vessels
o Conjunctival chemosis (swell of the conjunctiva)
o Conjunctival follicles (round collections of lymphocytes appearing as small dome-shaped nodules)
o Conjunctival papillae (associated with allergic immune response)
What are the appropriate investigations for conjunctivitis?
o Usually a diagnosis by history and examination
o Any further investigations that are required are done by specialists
Define glaucoma.
Optic neuropathy with typical field defect usually associated with ocular hypertension (intra-ocular pressure > 21 mm Hg).
What are the causes of glaucoma?
o Primary Causes = Acute closed-angle glaucoma (ACAG), Chronic closed-angle glaucoma, Primary open-angle glaucoma (POAG)
o Secondary Causes = Trauma, Uveitis, Steroids, Rubeosis iridis (formation of new blood vessels on the surface of the iris)
o Congenital = Buphthalmos (enlargement of the eye balls)
What are the presenting symptoms of glaucoma?
o ACAG = Painful red eye, Vomiting, Impaired vision, Haloes seen around lights
o POAG = Usually asymptomatic, Peripheral visual field loss
o Congenital = Buphthalmos, Watering, Cloudy cornea
What are the clinical signs of glaucoma on examination?
o ACAG = Red eye, Hazy cornea, Loss of red reflex, Fixed and dilated pupil, Eye is tender and hard on palpation, Cupper optic disc, Visual field defect, Moderated raised intra-ocular pressure
o POAG = Optic disc may be cupped, Usually no signs
What are the appropriate investigations for glaucoma?
o Goldmann Applanation Tonometry = Standard method of measuring intra-ocular pressure - Normal IOP = 15 mm Hg
o Pachymetry = Ultrasound or optical scanning to measure central corneal thickness (CCT) - CCT < 590 mm = higher risk of glaucoma
o Fundoscopy = Detects pathologically cupped optic disc
o Gonioscopy = Assess iridocorneal angle
o Perimetry (Visual Field Testing)
