Question:medium
Astigmatism in an emmetropic eye of an elderly person contributes to (the threshold above which laser/bioptics correction is needed):
Astigmatism in an emmetropic eye of an elderly person contributes to (the threshold above which laser/bioptics correction is needed):
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The cut-off above which LRIs fail and bioptics is needed.
Updated On: Jun 23, 2026
- +1D
- +2D
- +3D
- +4D
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The Correct Option is C
Solution and Explanation
Step 1: Frame this as a surgical-planning cut-off. In an older emmetrope having a presbyopia-correcting IOL, the surgeon must decide whether incisional astigmatism control will suffice.
Step 2: The literature sets the boundary at high astigmatism, meaning more than 3 dioptres. Below it, limbal relaxing incisions usually do the job; above it, a staged laser enhancement (bioptics) is planned.
Step 3: So the magnitude that defines significant pre-existing astigmatism in this scenario is $+3\,D$. The other options either sit safely under the threshold ($+1\,D$, $+2\,D$) or beyond it ($+4\,D$).
Step 4: The threshold value asked for is plus three dioptres.
\[\boxed{+3\,D}\]
Step 2: The literature sets the boundary at high astigmatism, meaning more than 3 dioptres. Below it, limbal relaxing incisions usually do the job; above it, a staged laser enhancement (bioptics) is planned.
Step 3: So the magnitude that defines significant pre-existing astigmatism in this scenario is $+3\,D$. The other options either sit safely under the threshold ($+1\,D$, $+2\,D$) or beyond it ($+4\,D$).
Step 4: The threshold value asked for is plus three dioptres.
\[\boxed{+3\,D}\]
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