Ophtalmology Flashcards
What are cataracts?
Opacification of the lens of the eye
Summarise the epidemiology of cataracts
Major cause of treatable blindness worldwide
Explain the aetiology of cataracts
Most are idiopathic (age-related)
Secondary causes:
Local: previous eye trauma, uveitis
Systemic: DM, metabolic (Wilson’s), skin disease (scleroderma), drugs (steroids)
Congenital: congenital rubella syndrome
What are the presenting symptoms of cataracts
Gradual onset painless loss of vision
Glare from bright light
Vision worsens in bright light
Monocular diplopia w haloes around lights
What are the signs O/E of cataracts
Loss of red reflex
Hazy lens appearance
Reduced visual acuity
How are cataracts investigated?
Usually unnecessary
What is conjunctivitis?
Inflammation of the conjunctiva
Summarise the epidemiology of conjunctivitis
Worldwide
Affects any age group
No gender, ethnic of social preponderance
Explain the aetiology of conjunctivitis
Infectious: viral, bacterial
Non-infections:
- allergic
- mechanical/irritative/toxic
- immune-mediated
- neoplastic
What are the risk factors for conjunctivitis?
Exposure to infected person Infection in one eye - spread to other eye Environmental irritants Allergen exposure Camps, swimming pools, military bases Asian/Mediterranean young male Atopy Contact lens use Ocular prosthesis Mechanical irritation
What are the presenting symptoms of conjunctivitis?
Red eye (generalised, bilateral)
Irritation, discomfort, grittiness
Discharge:
watery = viral
ropy, mucoid = allergic
purulent = bacterial
Itching = allergic
Eyelids stuck together in morning = bacterial + viral
Photophobia (suggests corneal involvement)
Visual acuity usually unaltered
What are the signs O/E of conjunctivitis?
Conjunctival follicles (round collections of lymphocytes appearing as small dome-shaped nodules) - viral
Conjunctival injection (ie bloodshot eyes)
Dilated conjunctival vessels
Conjunctival chemosis (swelling)
Conjunctival papillae
How is conjunctivitis investigated?
Rapid adenovirus immunoassay: +ve in adenovirus infection
- tear fluid sample
- 10 mins
Cell culture
Gram stain
What is glaucoma?
Optic neuropathy with typical field defect usually associated with ocular hypertension (intra-ocular pressure > 21 mmHg
What is unilateral conjunctivitis more likely to be caused by?
Bacterial infection
Summarise the epidemiology of glaucoma
Prevalence:
1% in over 40s
10% in over 80s
3rd most common cause of blindness worldwide
What are the presenting symptoms of glaucoma?
ACAG:
- painful red eye
- vomiting
- impaired vision
POAG:
- usually asymptomatic
- peripheral visual field loss
Congenital:
- buphthalmos
- watering
- cloudy cornea
What are the signs O/E of glaucoma?
ACAG:
- 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
- moderately raised intra-ocular pressure
POAG:
- optic disc may be cupped
- usually no signs
How is glaucoma investigated?
- Goldmann Applanation Tonometry
- standard method of measuring IOP
- normal IOP = 15 mmHg - Pachymetry
- use US/optical scanning to measure central corneal thickness
- CCT < 590mm = higher risk of glaucoma - Fundoscopy - detects pathologically cupped optic disc
- Gonioscopy - assess iridocorneal angle
- Perimetry - visual field testing
What is uveitis?
Inflammation of one or all parts of the uvea, the vascular area between the retina and sclera of the eye
Anterior uvea = iris + ciliary body
Posterior uvea = choroid + retina + retinal vasculature
Summarise the epidemiology of uveitis
Uveitis associated with spondyloarhritis is 2x common in males
Explain the aetiology of uveitis
- Infection, eg herpes simplex
- Manifestation of systemic inflammatory conditions, eg RA, ankylosing spondylitis, IBD, sarcoidosis, Behcet’s disease
- Sympathetic ophthalmia
What are the risk factors for uveitis?
Inflammatory diseases of joints, bowel, or skin
HLA-B27 positive
Ocular trauma
What are the presenting symptoms of uveitis?
Pain due to inflammation Pain during accommodation Blurred vision Tearing Photophobia Floaters Eye redness wo discharge
Rarely associated w tubulointerstitial nephritis - flank pain, haematuria, proteinuria
What are the signs O/E of uveitis?
Reduced visual acuity
Ciliary flush
Hypopyon - exudate and inflammatory cells in inferior angle of anterior chamber
Small irregular pupil due to adhesion of iris to lens
Slit lamp - keratic precipiates
How is uveitis investigated?
Ix for associated systemic conditions
Eg spondyloarthritides - sacroiliac joint XR, HLA-typing
What is sympathetic ophthalmia?
Inflammation of contralateral eye weeks/months after penetrating injury due to recognition of eye antigens in CL eye by T-cells that were activated by injury to opposite eye
