مقايسه تستهاي تيزبيني اسنلن و حساسيت كانتراست در مراحل اوليه كاتاراست سينل

Comparison of Visual Acuity Snellen and Contrast Sensitivity in Early Senile Cataract

Some authors in the world have suggested that cataracts at any stage of development can reduce contrast sensitivity and visual acuity. The purpose of this study was to compare contrast sensitivity and visual acuity on patients with early senile cataract. With convenience sampling method. Visual acuity and contrast sensitivity were assessed in 70 subjects (102 eyes) who had early senile cataract. Visual acuity was measured with the Snellen letter chart. Contrast sensitivity was measured with the Cambridge Low Contrast Gratings test. Early senile cataracts were associated with poorer acuity and lower contrast sensitivity scores. In comparison with early nuclear cataract, th,e effect of early posterior subcapsular cataract on visual acuity and contrast sensitivity was greater than that of early nuclear cataract. For early subcapsular cataract, measurement of contrast sensitivity provides more information than visual acuity alone. Using contrast sensitivity in combination with visual acuity gives a better assessment of visual system function on patients with early senile cataract. Therefore beside visual acuity, contrast sensitivity should be measured as well, especially on patients with early posterior subcapsular cataract.