Stereoacuity testing in patients with retinal and optic nerve disorders

A study comparing the relative sensitivity for detecting abnormal stereoacuity in patients with retinal or optic nerve disease on clinically used stereoacuity tests is not available. It is also not apparent from the ophthalmic literature if optic nerve or retinal diseases are likely to have a greater impact on stereoacuity performance. We were also interested in determining a level of visual acuity loss that would likely results in an impairment of stereoacuity on these clinical tests. Forty-two patients with various retinal and optic nerve disorders and eighteen normal subjects were evaluated for stereoacuity using three tests: Titmus Stereoacuity Test (TST), Randot Stereoacuity Test (RST), and TNO Stereoacuity Test (TNO). The performance on these three stereoacuity tests was compared with the normal subjects. Additionally, TST scores from our patients were compared to predicted TST scores derived from a previously published nomogram. For patients with retinal and optic nerve disease, an abnormal score on one clinical test of stereoacuity was likely to predict an abnormality on the other tests. Performance on the TST relative to the predicted value derived from a nomogram was not significantly different for patients with retinal vs. optic nerve disease. With some exceptions, patients with visual acuities of 20/30 or worse in at least one eye were likely to show abnormal stereoacuity.