Date of Award
Master of Science in Vision Science
Scott C. Cooper
The purpose of the study is to further the clinician's understanding in the impact of near point visual effort during the onset of cycloplegia on the accuracy of cycloplegic refractions. Twenty-one optometry students participated in the study: six were female and fifteen were male. Ten subjects had myopia with spherical equivalents greater than -3.00D. Two subjects had hyperopia with spherical equivalents greater than +1.00D. The remaining nine subjects refractive errors ranged from + 1.00D to -3.00D. Subjects were cyclopleged with one drop of Cyclopentolate HCl 1%. Each subject was tested under two randomized conditions: cycloplegic adaptation with near point effort, and cycloplegic adaptation without near point effort. At 30, 45 and 60 minutes from instillation of the drops, four measurements of refractive error and residual accommodation were obtained using the Canon R-1 autorefractor. Results were analyzed using the One Factor ANOVA-Repeated Measures statistical test. All significant effect was seen between the two conditions of cycloplegic onset. For the interaction between condition and time, cycloplegia without accommodative effort shows more myopia (-0.146D, p=0.0001) than with the near viewing condition. The low refractive error group showed a slight hyperopic shift (0.212 D, p= 0.0002) following accommodative effort versus the condition with no accommodative activity. Although seemingly paradoxical trends were found which were statistically significant, the magnitude of these trends may not be considered clinically significant. There may, however, be individual patients who are more susceptible to these effects. It is therefore recommended that patients cycloplege without intense accommodative effort during onset as this will provide consistent results without careful monitoring of the patient. Other considerations are also discussed.
Chaney, Michelle Wika and Rasmussen, Lynda L., "The effects of near point stress on cycloplegic examinations" (1997). College of Optometry. 1224.