Posterior Chamber/ Refractive Errors Flashcards
Loss of red reflex, gradual loss of color vision and VA, poor night vision, difficulty with reading fine print
Cataract
Causes/risk factors of cataracts
Aging, trauma, diabetes, smoking, sunlight, congenital
Cataract TX
Wait for cataract to mature
Surgical TX (artificial lens)
VA < 20/20
Refractive error
Gradual loss of near vision, px is holding reading material far away from their eyes
Presbyopia
What happens to the eye in presbyopia?
Lens hardens and loses its flexibility
Slow progressive failure of accomodation
What does the px develop if they have presbyopia?
Hyperopia (farsightedness)
Presbyopia TX
Reading glasses
Refer to optometrist for proper fitting
Myopia
Nearsightedness
What anatomical defect causes myopia?
The globe is too big and causes the image to fall in front of the retina which causes it to be perceived as blurry
Myopia TX
Corrective lenses
Hyperopia
Farsightedness
What anatomical defect causes hyperopia?
The globe is too small and causes the image to fall past the retina
Hyperopia TX
Corrective lenses
Astigmatism
Change in corneal shape that causes blurring
Amblyopia
Reduction in VA due to abnormal childhood development
Amblyopia is commonly unliateral/bilateral?
Unilateral
≥ 2 line difference in VA
VA > 20/40 in PX 4+
VA > 20/50 in PX ≤ 2
Amblyopia
Amblyopia TX
Patching
How does patching work? How long do you patch for?
Patch the good eye to strengthen the bad eye
2 hours/day
3 types of amblyopia
Strabismic
Refractive
Deprivational
Most common type of amblyopia
Strabismic
Strabismic amblyopia is also known as
Lazy eye
What happens in amblyopia is left untreated? Why is this important?
Brain will shut down the eye to prevent diplopia
Very difficult to TX once eye is shut down
What are the 4 types of strabismus?
Esotropia (inward)
Exotropia (outward)
Hypertropia (upward)
Hypotropia (downward)
Image in one eye is not focused due to uncorrected refractive error(s)
Refractive amblyopia
Least common but most severe form of amblyopia
Deprivational amblyopia
What can causes deprivational amblyopia?
Congenital cataracts
Ptosis
Vitreous hemorrhage
Severe refractive errors
When to refer a PX to ophthalmology for suspected amblyopia?
2+ line difference in VA between eyes
VA worse than 20/40 in PX 4+
VA worse than 20/50 in PX ≤ 2
Abnormal ocular alignment
Abnormal red reflex
Asymmetric vision
Unilateral Ptosis
Lesion obscuring visual axis
Key hole pupil
Coloboma
Coloboma cause
Chromosome 22 defect
Trauma
What is important to remember about coloboma?
Can extend farther back into the eye
Vision can be affected
