Slab-off prism for symptomatic, vertical heterophoria in the reading position

To describe uncommon techniques that induce compensatory strabismus utilizing slab-off spectacle prism to treat symptomatic incomitant vertical strabismus in adults with diplopia in the reading position only.

The medical records of consecutive patients having a chief complaint of diplopia in the reading position that was treated with slab-off prism correction were reviewed retrospectively. Success of the slab-off spectacle prism correction was determined at the follow-up visit or by phone call for any patients who did not return for a follow-up examination.

Five adult subjects were identified, ranging in age from 55 to 75 years (mean age, 65.6 years). All 5 patients complained of vertical diplopia during reading. Symptoms resolved with slab-off prism in all 5 cases. Three patients had symptomatic incomitant vertical strabismus occurring only in the reading position. All 3 of these patients remained in slab-off prism at in-office follow-up.

Slab-off spectacle prism in non-digitally manufactured multifocal lens prescriptions was an effective nonsurgical treatment option in this descriptive study of 5 patients with diplopia in the reading position only, 3 of whom had symptoms related to small-angle vertical strabismus in the reading position only, without anisometropia.