The effects of hyperopic and astigmatic ametropia on stereoacuity by Titmus stereo test

Abstract Purpose Using the Titmus stereo test to examine the association between hyperopic ametropia including hyperopia, astigmatism, anisometropia, and stereoacuity in a school-aged population. Methods We measured cycloplegic autorefraction, best corrected monocular visual acuity and best corrected stereoacuity in a population of 4- to 13-year-old school-aged children (Keelung, Taiwan) after obtaining proper informed consent. Children with amblyopia (best-corrected visual acuity inferior to 20/25) or strabismus were excluded from the study. The effects of the severity of hyperopia, astigmatism, and anisometropia on stereoacuity revealed by the Titmus stereo test were analyzed. Results One hundred and seventeen children (51 boys and 66 girls; mean age = 7.32 years, range = 4–13 years) with hyperopia were enrolled into the study. The mean spherical error was +1.48 ± 1.30 diopters (D) (range = +0.25 to +6.50D). The mean astigmatism was -1.22 ± 1.04 D (range = 0 to -3.50 D). They received the Titmus stereo test. A spherical error > +3.00 D and spherical equivalent > +3.00 D showed a strong association with decreased stereoacuity in the Titmus stereo test ( p  = 0.000). The degree of astigmatism or astigmatic anisometropia was not significantly correlated with the stereopsis in the test. Conclusion The Titmus stereo test revealed a good quantification of the stereoacuity. A spherical error > +3.00 D, and a spherical equivalent > +3.00D were all associated with a significantly reduced stereoacuity in school-aged children.