VISION AFTER PUPIL DILATION

Sonia Sharma Kelley

Abstract

PURPOSE. This study examines the change in high and low contrast visual acuity (VA) in the elderly after pupil dilation. Sixty male patients (115 total eyes) with a median age of 65 (range of 36-83) were examined at the Veterans Administration Medical Clinic in Canton, Ohio. METHOD. Pupil size and monocular low and high contrast VA pre-and post-dilation were measured. All VA measurements were made using Bailey-Lovie charts at 2 meters.

RESULTS. Low contrast VA decreased from an average of 49.4 letters to 40.2 letters, an average of 9.2 letters (SD=9.5). High contrast VA decreased from an average of 60 letters to 52.7 letters, an average of 7.3 letters (SD=7.9). Twenty-eight eyes (24%) saw less than 55 letters (20/38 snellen equivalent) pre-dilation on the high contrast VA chart. Fifty-seven eyes (50%) saw less than 55 letters (20/38 Snellen equivalent) post-dilation on the high contrast VA chart. Thirty-three eyes (29%) that saw better than 55 letters before dilation dropped to below 55 letters after dilation on the high contrast VA chart. The decrease in low contrast VA in the left eye was 8.8 letters (SD 9.8) and in the right eye averaged 9.6 (SD=9.3 The decrease in high contrast VA in the left eye averaged 7.2 (SD=8.1) and in the right eye averaged 7.5 (SD=7.9). For low contrast VA, adults with good baseline low contrast VA (>40 letters) lost an average of 5.6 letters more after dilation than those with poor baseline VA (p=0.0001); older adults (>60 years) lost an average of 5 letters more after dilation than younger adults after dilation (p=0.0001); for each 1-mm increase in post-dilation pupil size, an average of 1.68 letters of low contrast VA was lost (p=0.06). For high contrast VA, adults with good baseline high contrast VA (> 50 letters) lost an average of 4.9 letters more after dilation than those with poor baseline high contrast VA (p=0.0021).

CONCLUSIONS. The factors which caused the greatest decrease in low contrast VA after pupil dilation were poor baseline low contrast VA, older age (>60 years) and a large change in pupil size with dilation. High contrast VA was reduced after pupil dilation if the patient had good baseline high contrast VA.

Details

Year: 2001

Program Number: Poster 66

Author Affiliation: The Ohio State University

Co-Authors: G. Lynn Mitchell, Thomas Stokkermans, Karla Zadnik

Co-Author Affiliation: The Ohio State University, CWRU School of Medicine, The Ohio State University

Room: Exhibit Hall C