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Grating visual acuity with Teller cards compared with Snellen visual acuity in literate patients
B J Kushner1, N J Lucchese, G V Morton
1University of Wisconsin Hospital and Clinic, Madison, USA.
Archives of Ophthalmology (Chicago, Ill. : 1960)
|April 1, 1995
Summary
Teller Acuity Cards may underestimate vision deficits, including amblyopia and legal blindness. Even normal Teller card results may mask significant visual loss detected by Snellen acuity tests.
Area of Science:
- Ophthalmology
- Vision Science
- Clinical Research
Background:
- Accurate visual acuity assessment is crucial for diagnosing and managing vision impairments.
- Standardized tests are needed to detect varying degrees of vision loss, from amblyopia to legal blindness.
Purpose of the Study:
- To evaluate the effectiveness of Teller Acuity Cards in identifying three distinct levels of vision deficit.
- To compare Teller card acuity with Snellen visual acuity as a gold standard.
Main Methods:
- A prospective, masked study compared grating visual acuity using Teller cards with Snellen visual acuity.
- The study included 69 literate patients diagnosed with amblyopia or other causes of vision loss.
Main Results:
- Teller card acuity showed a significant correlation with Snellen acuity (r = .508), but explained only 26% of its variation.
- Sensitivity was low for detecting deficits of 20/40 (58%), 20/70 (39%), and 20/200 (24%).
- Positive predictive values were higher for near Snellen acuity (80% for 20/70, 43% for 20/200), while specificity was high (88% for 20/70, 98% for 20/200).
Conclusions:
- Teller Acuity Cards may underestimate amblyopia, legal blindness, and vision impairment at the 20/70 level.
- Normal Teller card results do not exclude significant visual loss when assessed by Snellen optotypes.