Common Vision Defects

Cards (56)

  • Name 8 common visual defects.
    Uveitis
    Cataract
    Retinal detachment
    Glaucoma
    Myopia
    Hyperopia
    Astigmatism
    Presbyopia
  • What is uveitis?
    Inflammation of uveal tract (iris, ciliary body, choroid)
  • What are the different types of uveitis?
    Anterior
    Intermediate
    Posterior
    Panuveitis
  • What is anterior uveitis?
    Inflammation of anterior part of uveal tract (iritis, iridocyclitis (iris & ciliary body))
    Most common type of uveitis
  • What is intermediate uveitis?
    Inflammation of middle part of uveal tract
    -> mainly vitreous
  • What is posterior uveitis?
    Inflammation of posterior part of uveal tract
  • What is panuveitis?
    Inflammation of whole of uveal tract
  • What are the common symptoms of uveitis?
    Blurred vision
    Pain
    Redness
    Photophobia
    Floaters (commonly seen in posterior uveitis)
  • What is shown in the image?
    Anterior uveitis
  • What are the symptoms of anterior uveitis?
    Redness
    Pain
    Photophobia
    Intraocular pressure may be raised
  • What is the treatment of anterior uveitis?
    Topical steroids
    Dilating pupil (cyclopentolate) -> prevents formation of posterior synechiae
    If intraocular pressure is raised
    • topical beta blockers
    • prostaglandin analogues
    • referral to ophthalmology
  • What are the signs & symptoms of intermediate uveitis?
    Painless
    Blurred vision
    Floaters
    Commonly affects both eyes
  • What is the treatment for intermediate uveitis?
    Combination of anterior & posterior treatments
  • What are the signs & symptoms of posterior uveitis?
    Painless
    Blurred vision
    Can progress to severe visual loss
    Floaters
    Scotomata
    Blind spots
    Often found with systemic autoimmune diseases
  • What are the treatments of posterior uveitis?
    Steroids
    In need long-term steroids, give second-line immunosuppressant
    Biological agents can be used in severe cases (e.g. adalimumab)
  • What is cataracts?
    Clouding of the eye's lens
  • What is shown in the image?
    Cataracts
  • What are the signs & symptoms of cataracts?
    Gradual, painless deterioration of vision
    Glare (esp at night)
  • What are the risk factors of cataracts?
    > 65 years old
    Female
    Smoking
    Long term UV exposure
    Diabetes
    Eye trauma
    Long term corticosteroid use
    FH of congenital catarct
    Uveitis
    Myopia
  • How is being over 65 a risk factor for cataracts?
    Change in lens proteins increases with age & reduce transparency
  • How is being female a risk factor for cataracts?
    May be due to reduction if protective effect of oestrogen during menopause
  • How is smoking a risk factor for cataracts?
    Oxidative stress is linked to changes in crystalline lens proteins -> cataracts
  • How is long-term UV exposure a risk factor for cataracts?
    Lens is susceptible to UV damage
  • How is diabetes a risk factor for cataracts?
    High glucose levels -> retention of glucose in the lens & conversion to sorbitol
  • How is uveitis a risk factor for cataracts?
    Due to prolonged ocular inflammation & use of corticosteroids
  • What is the treatment of cataracts?
    Early changes in lens
    -> correctable with glasses
    But, eventually opacification needs surgical intervention
    Cataract extraction (incision into eye & removal of opacified crystalline lens) with insertion of an intraocular lens
  • What is retinal detachment?
    Separation of the retina from the underlying tissue.
  • What is the process of retinal detachment?
    Tear in retina -> fluid collects in potential space between sensory retina & pigment epithelium -> fluid continues to leak behind retina & with gravity -> retinal detachment
  • What are the signs & symptoms of retinal detachment?
    Sudden onset of floaters
    Photopsia (flashes of light) -> prior to detachement
    Painless, progressive visual field loss
  • What are the risk factors of retinal detachment?
    Posterior vitreous detachment
    Age
    Myopia
    Trauma
    Previous ophthalmic surgery
    Previous cataract surgery
    Intraocular tumour
    Vitreous haemorrhage
    Diabetes
  • Why is age a risk factor of retinal detachment?
    Due to structural changes in vitreous gel -> promotes retinal breaks
  • Why is myopia a risk factor for retinal detachment?
    High myopia may accelerate the breakdown of normal vitreous gel & weaken retina
  • What is the treatment for retinal detachment?
    Referral to ophthalmologist for detailed fundal examination
    Surgery to re-attach retina or fix retinal tear
  • What is glaucoma?
    A group of eye diseases that cause damage to the optic nerve.
  • What is glaucoma due to?
    Increased pressure inside the eye -> optic nerve damage -> visual field defects (loss of vision)
    2nd most common cause of blindness worldwide
  • What are the 2 main types of glaucoma?
    Primary open-angle glaucoma
    Acute angle-closure glaucoma
  • What is shown in the image?
    Primary open-angle glaucoma
  • What is primary open-angle glaucoma?
    Most common form of glaucoma
    Due to reduced outflow of aqueous humour through trabecular meshwork -> high intraocular pressure
  • What are the risk factors of primary open-angle glaucoma?
    Older age
    Race (black Africans have a 5x greater risk than white)
    Positive FH
    Myopia
  • What are the signs & symptoms of primary open-angle glaucoma?
    Gradual, painless loss of peripheral visual fields
    Raised intraocular pressure
    Optic disc cupping