Comparação entre os testes de acuidade visual E de Snellen e Sheridan-Gardner

Comparação entre os testes de acuidade visual E de Snellen e Sheridan-Gardner

Autores:

Renata Cecília Carnelossi Lopreto,
Isabelle Hautequest Meirelles,
André Domingos Araujo Souza,
Antonio Augusto V. Cruz

ARTIGO ORIGINAL

Arquivos Brasileiros de Oftalmologia

versão impressa ISSN 0004-2749versão On-line ISSN 1678-2925

Arq. Bras. Oftalmol. vol.62 no.1 São Paulo fev. 1999

http://dx.doi.org/10.5935/0004-2749.19990055

SUMMARY

Purpose:

To compare the visual acuity measurement using the Snellen E and the Sheridan-Gardner test.

Methods:

Three experiments were perfonned. ln the first, the visual angles and the time necessary to measure the visual acuity of children were compared. ln the second, psychometric functions obtained in different conditions of blur were compared when the Snellen E and the Sheridan-Gardner test were used. ln the third, the ejfect of a low-pass filter on the letters E, H, T, V and O was analyzed.

Results:

The time necessary to measure the visual acuity of children and the visual angles obtained are smaller with the Sheridan-Gardner test than with the Snellen E. The effect of optical blur is greater with the Snellen E than with the Sheridan-Gardner test. Low-pass filtering affects more the E than the optotypes H, T, V and O.

Conclusions:

Even when the visual angles are identical, the considered equivalent tests.

Keywords: Visual acuity; Optotypes; Filtering; Optical blur

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