Station 6
(allowed 5 minutes)
This 70 year-old woman is due to have a cataract extraction. Her A-scan taken in the pre-assessment clinic 
is shown above.

a. Which eye is this A-scan taken from?

b. What are the three peaks (A, B & C) shown here?

c.What is the required lens power for emmetropia assumming the A constant is 118 and her average 
    keratometry is 44.0D?

d. If the axial length were overestimated by 1mm would the resultant lens implant (which you aim for 
    emmetropia) give rise to hypermetropia or myopia?

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