Impact of therapeutic prism treatment on ocular motor cranial nerve palsies among Moroccan patients.

PURPOSE: This study evaluates the effectiveness of prism therapy in patients with ocular motor palsies affecting the oculomotor (nerve III), abducens (nerve VI), and trochlear (nerve IV) nerves, focusing on four key criteria: deviation, diplopia, head posture, and ptosis.

METHODS

A comparative analysis was conducted on patients diagnosed with nerve III, nerve VI, or nerve IV palsy. Deviation measurements, diplopia occurrence, head posture abnormalities, and ptosis presence were assessed before and after prism therapy. Statistical analysis was performed to determine significant changes within each group and to compare outcomes across the three palsy types.

RESULTS

Therapeutic prism use resulted in significant improvements in ocular deviation and diplopia across all groups (p < .05). Mean deviation decreased from 22Δ to 12Δ in third nerve palsy, from 38Δ to 14Δ in sixth nerve palsy, and from 18Δ to 8Δ in fourth nerve palsy. Diplopia in primary gaze was reduced from over 80% to below 21% across all groups. Although cyclodeviation was observed only in 29% of fourth nerve palsy cases, 71% of those patients reported subjective improvement. No statistically significant differences were found between the groups regarding treatment success (p > .9).

CONCLUSION

Prism therapy appears effective in improving ocular alignment and visual symptoms across all three types of ocular motor palsy. Its benefits extend to reducing diplopia and abnormal head posture, and selectively improving ptosis and torsional symptoms in certain cases. These findings support the broader application of prism therapy as a valuable non-surgical management strategy.