Ophthalmology Flashcards
What is cataracts?
Opacification of the lens of the eye
What is the aetiology of cataracts?
Majority of cases are idiopathic age-related (senile cataracts). Numerous secondary causes including:
- Local: Previous eye trauma, uveitis, intraocular tumours
- Systemic: DM, metabolic disorders (hypocalcaemia, Wilsons disease), skin disease (atopic dermatitis, scleroderma), drugs (steroids), X-ray and UV radiation, myotonic dystrophy, genetic syndromes (Down’s)
- Congenital: Congenital rubella syndrome
What is the aetiology of cataracts?
Major cause of treatable blindness worldwise
What are the presenting symptoms of cataracts?
- Gradual onset painless loss of vision
- Glare from bright light, vision may worsen in bright light (especially with central lens opacity)
- May experience monocular diplopia and see haloes around lights
- May notice that they can read without glasses (nuclear sclerotic cataract may increase lens-converging power)
- In infants, may be amblyopia or nystagmus
What are the signs of cataracts on examination?
- Loss of reflex and hazy lens appearance
- Reduced visual acuity
What are the investigations for cataracts?
Unnecessary unless occurring at an early age or in background of systemic disease
What is conjunctivitis?
Inflammation of the lining of the eyelids and eyeball caused by bacteria, viruses, allergic or immunological reactions, mechanical irritation or medicines
What is the aetiology of conjunctivitis?
- Most common bacterial pathogens in infective include Pneumococcus, Staphylococcus aureus, M. catarrhalis and H. influenzae
- Viral: adenovirus, herpes simplex, Epstein-Barr, varicella zoster and enteroviruses
- Contact lens wear may lead to a keratoconjunctivitis
- Mechanical caused by chronic conjunctival irritation especially while sleeping.
What is the epidemiology of conjunctivitis?
Commonly affects males and females of all ages
What are the presenting symptoms of conjunctivitis?
- Watery discharge
- Itchy predominant symptom
- Eyelids stuck together
- Eyelids stuck together in mornings
What are the signs of conjunctivitis on examination?
- Ropy, mucoid discharge
- Prululent discharge
- Tender, pre-auricular lymphadenopathy
What are the risk factors for conjunctivitis?
- Exposure to infected person
- Infection in one eye
- Environmental irritants
- Allergen exposure
- Camps, swimming pools, military bases
- Asian or Mediterranean young male
- Atopy
- Contact lens use
- Ocular prosthesis
- Mechanical irritation
What are the investigations for conjunctivits?
- Rapid adenovirus immunoassay: 2 visual lines equal positive
- Cell culture
- Gram stain
- PCR
What is glaucoma?
Optic neuropathy with typical field defect usually associated with ocular hypertension (intraocular pressure more than 21mmHg)
What is the aetiology of glaucoma?
- Primary causes: Acute close angle glaucoma (ACAG), primary open-angled glaucoma (POAG), chronic closed-angle glaucoma
- Secondary causes: Trauma, uveitis, steroids, rubeosis iridis (diabetes, central retinal vein occlusion)
- Congenital: Buphthalmos, other inherited ocular disorders