Abstract
Purpose :
Stereopsis, a binocular phenomenon dependent on higher order visual processing, can reliably suggest a range of visual acuity (VA) in patients with no history of strabismus1. Michael Brodsky, M.D.2 suggested that patients with bitemporal hemianopias may demonstrate absence of stereopsis on reverse stereovision testing. Prior to testing Dr. Brodsky’s hypothesis, we showed that there was no difference between traditional stereoacuity (stereoacuity book upright, “TS”) and reverse stereoacuity (stereoacuity book rotated 180 degrees, “RS”) in patients without visual field defects3. Here we report the results of TS and RS testing in patients with homonymous hemianopias (HH) and bitemporal hemianopias (BTH).
Methods :
Patients with HH or BTH and good VA (>20/50) seen in a neuro-ophthalmic service over a 2.5-year period underwent a detailed examination, including polarized vectogram stereoacuity measurements (Titmus). Patients were first tested with TS and then RS. Patients with strabismus were excluded.
Results :
Of 74 patients with HH or BTH, we included 61 who had no ocular misalignment and >0 circles on TS. 34/61 had HH (56%; median age, 52 years [19-77]) and 27/61 had BTH (44%, median age, 51 years [21-70]). Mean score for HH was 7.3/9 circles correct on TS and 6.9/9 on RS [p=0.34]. Mean score for BTH was 5.3/9 on TS and 5.0/9 on RS [p=0.63]. Patients with HH scored better than patients with BTH on both TS (7.3/9 vs 5.3/9, respectively [p=0.003]) and RS testing (6.9/9 vs 5.0/9, respectively [p=0.02]). The mean difference between TS and RS (TS-RS) was 0.35 circles for HH and 0.26 circles for BTH [p=0.89].
Conclusions :
Patients with HH scored significantly better than patients with BTH on both TS and RS. However, there was no significant difference between TS and RS for HH or for BTH patients and there was no significant TS-RS difference between HH and BTH patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.