Amblyopia & Strabismus

Question 1

amblyopia: definition

Answer 1

• lazy eye
• have to have diminished vision for it to actually be a lazy eye
• can be caused by any interruption in visual development (happening from birth to about age 7-8)

Question 2

amblyopia: etiology

Answer 2

• lack of neuro-sensory stimulation due to strabismus (conflicting images) or blurred retinal image

Question 3

strabismic amblyopia

Answer 3

• most common cause of amblyopia = strabismus

- brain still adaptive so there will be a suppression of the image from the deviated eye

Question 4

refractive amblyopia

Answer 4

• result from difference in refractive errors b/w the eyes

- eye w/ less refractive error gives clearer image making other eye susceptible to amblyopia

Question 5

form deprivation amblyopia

Answer 5

• aka amblyopia ex anopsia
• result of inadequate sensory input from opacity in ocular media or occlusion of eye
• ex: cataract, corneal scar, ptosis

Question 6

tx of amblyopia

Answer 6

• early dx and tx underlying cause
• occlusion therapy = patching non-affected eye
• pharmacological penalization: if pt very noncompliant w/ patch schedule you can blur the good eye w/ atropine

Question 7

strabismus

Answer 7

• latent or manifest misalignment b/w eyes

- children’s eyes not full size yet so naturally they are hyperopic

Question 8

tests for strabismus

Answer 8

• Hirschberg reflex: look at alignment of light reflection on the corneas
• cover test
• alternate prism cover test

Question 9

tx of strabismus

Answer 9

• normalize VA and tx amblyopia if present
• equalize vision = tx anisometropia if present; tx hyperopia is pt is esotropic
• surgery if misalignment persists after pt gets glasses
• vision therapy usually not helpful