Ophthalmology Flashcards
Define glaucoma
Progressive optic neuropathy characterised by typical optic disc changes and typical visual field defects, usually due to increased intraoccular pressure >21mmHg.
Summarise the aetiology of glaucoma
Primary glaucoma:
Open angle glaucoma
Closed angle glaucoma - acute and chronic
Secondary glaucoma: Trauma Uveitis Steroids Rubeosis iridis (new abnormal blood vessels on the iris formed by neovascularisation) - due to diabetes or central retinal vein occlusion
Congenital: Bupthalmos (enlargement of the eye balls)
What are the risk factors of glaucoma?
Closed angle: Female sex Hyperopia (long-sighted) Family history Asian ethnicity Advanced age
Open angle: Afro-Caribbean ethnicity Increased intraoccular pressure Age >50 Hypertension Diabetes Mellitus Myopia ‘short sighted’
Summarise the epidemiology of glaucoma
Glaucoma is the 2nd leading cause of blindness in the world
Primary open angle is the most common type of glaucoma
45 million people worldwide
One third due to primary angle closure glaucoma
Angle closure glaucoma more common in Asians
Angle closure glaucoma more common in women
Acute angle closure most common between 55 and 65 years old
What are the presenting symptoms of glaucoma?
Open angle:
Often asymptomatic
Peripheral visual field loss which can then progress to central loss
Closed angle: Abrupt onset of symptoms Painful eye Red eye Blurry vision Headaches Nausea Visual halos Aching eye or brow pain
Congenital:
Bupthalmos
Watering
Cloudy cornea
What are the signs on physical examination of glaucoma?
Closed angle: Red eye Hazy cornea Loss of red reflex Fixed and dilated pupil Eye is tender and hard on palpation Cupped optic disc Visual field defect Raised intra-ocular pressure
Open angle:
Optic disc may be cupped
Usually NO signs
What are the appropriate investigations for glaucoma?
Visual fields testing:
Arcuate scotoma - partial loss of vision in otherwise normal field
Peripheral field loss (tunnel vision) as late stage
Fundoscopy/Optic nerve imaging - cupping of optic nerve
Goldman Applanation Tonometry - raised intra-ocular pressure >21mmHg. (Normal = 15mmHg)
Pachymetry - USS or optical scanning to measure corneal thickness - thin cornea (<590mm)
Gonioscopy - Assess iridocorneal angle - low in closed angle glaucoma
Define conjunctivitis
Inflammation of the lining of the eyelid and eyeball caused by most often viruses, but also bacteria, allergy, immunologic reactions, mechanical irritation or medicines
Summarise the aetiology of conjunctivitis
Most often viral: Most common cause is ADENOVIRUS EBV HSV VZV
Bacterial: Pneumococcus Staphylococcus aureus Chalmydia - causes chronic conjunctivitis Neisseria
Allergy
Mechanical irritation eg cataract use - excessive use, poor hygiene
Summarise the epidemiology of conjunctivitis
Affects all ages
Bacterial conjunctivitis is more common in children
Viral conjunctivitis is more common in adults
What are the presenting symptoms of conjunctivitis?
Red eye
Thin, watery discharge in viral and allergic
Thick, purulent discharge in bacterial
Itchy eye in allergic, burning sensation in viral
Unilateral involvement if viral, bilateral involvement if bacterial
Usually vision is unaffected
Photophobia if corneal involvement
What are the signs on physical examination of conjunctivitis?
Conjunctival injection (blood shot eye) Dilated conjunctival vessels Chemosis Tarsal conjunctival follicles in viral Conjunctival papillae
What are the appropriate investigations of conjunctivitis?
Mostly a clinical diagnosis
Can do rapid adenovirus immunoassay
Define cataracts
Opacification of the lens of the eye leading to a decreased visual acuity
Summarise the aetiology of cataracts
Idiopathic (part of ageing process) - MOST COMMON
Metabolic disorders - diabetes, Wilson’s
Inherited/congenital problems - congenital rubella syndrome
Trauma
Medications eg steroids
Infection - rubella
Scleroderma
Risk factors: Smoking UV exposure Age > 65 Diabetes mellitus Eye Trauma Long-term corticosteroid use Family history of congenital cataracts Uveitis
