Prism Therapy
The use of optical prisms (typically base-out for esotropia) to reduce diplopia and stabilize binocular fusion in acute-acquired-concomitant-esotropia and other strabismus conditions. 1
Clinical Applications in AACE
Base-out prisms may:
- Reduce or eliminate diplopia
- Stabilize fusion
- Improve quality of life
- Delay or avoid surgery
Optimal Candidates
Prisms are especially useful in:
- Small-angle AACE — deviations small enough to fully correct optically
- Fluctuating deviations — where surgery risks overcorrection during low-angle phases
- Early-stage disease — before chronic motor adaptation develops
- Pre-surgical planning — prism adaptation protocols to better predict surgical angle and reduce undercorrection 1
Combination Therapy
Recent evidence supports combining prism therapy with vision-therapy for better outcomes than either alone.
Limitations
- Not curative — addresses symptoms (diplopia) rather than underlying vergence imbalance
- Some patients adapt to prisms (require increasing power)
- Cosmetic concerns with high-power Fresnel prisms
- May not be sufficient for large deviations