Visual Dysfunctions Flashcards
What is the link between vision loss and AIDS?
Vision loss is a late complication of AIDS
Anopsia
Lack of vision in an eye due to interruption of an optic nerve
What does cortical visual impairment result from?
Damage to visual cortex (extent of vision loss depends on amount of damage)
Is the eye affected in cortical visual impairment?
No it is healthy (may be able to gain some vision back of vision stimulation is provided)
What is diabetic retinopathy?
Proliferation of blood vessels may cause hemorrhaging into vitreous or scar formation of retina (blurred vision)
When does diabetic retinopathy occur?
20 years after diabetes diagnosis (increased on how bad diabetes is and if it is controlled)
Glaucoma
Caused by increased pressure in eye due to faulty drainage system
What can occur if pressure continues in glaucoma?
Decreased blood supply so peripheral retina cells may die and damage optic nerve
What are symptoms of glaucoma in adults?
Poor night vision
Halos around eyes
Light sensitivity (photophobia)
Homonymous hemianopsia
Damage to optic tract which results in loss of vision to contralateral eye
Where does hemianopia most commonly occur?
Right side
How do brain stem strokes affect vision?
Difficulty with eye movements
Diplopia
Oscillopsia
Nystagmus
Oscillations of eyes (often present at birth)
How might eye movements be in someone with nystagmus?
Jerky or slow (could be result of neurological damage)
What is happening in a farsighted (hyperopic) eye?
Eyeball is too short and light rays focus behind fovea of the retina
What is happening in a near sighted (myopic) eye?
Eyeball is too long and light rays come to a focus before they reach the fovea of retina
Astigmatism
Irregular curvature of the cornea (visual fatigue)
Presbyopia
Lens becomes less flexible and less able to accommodate for near point viewing
What causes refractive errors in vision?
Size of eye, shape of cornea and retina (inherited)
Retinitis pigmentosa
Progressive retinal deterioration (slow progressive field loss)
How does blindness occur in retinitis pigmentosa?
Peripheral to tunnel vision or total blindness
What is a common symptom of retinitis pigmentosa?
Loss of night vision because rods are affected first
Retinopathy of prematurity
Proliferation of blood vessels through retina and vitreous stretches the retina and causes retinal detachment
Who does retinopathy of prematurity commonly affect?
Preemies that get prolonged oxygen
Strabismus
Deviation in position of one or both eyes due to muscle imbalance (lazy eye)
What is treatment of strabismus?
Surgery, visual training, or drugs (should be treated before 2 y/o as ability to correct decreases with age)
What are types of strabismus?
Esotropia (deviation toward nose)
Exotropia (deviation away from nose)
Hypertropia (deviation upward)
