Measuring refraction in adults in epidemiological studies.
OBJECTIVE
To compare refraction measured before and after pharmacologic cycloplegia.


METHODS
This study used preliminary data from the Beaver Dam Offspring Study, which includes adult children of participants in the population-based Epidemiology of Hearing Loss Study of older adults living in Beaver Dam, Wisconsin. Data were available for 5018 eyes of 2529 participants. Refraction was defined by the spherical equivalent (SE), using autorefractor readings. Differences were calculated as the SE after drops were administered minus the SE before drops were administered. Myopia was defined as SE of -1 diopter (D) or less; emmetropia, as SE more than -1 D and less than 1 D; and hyperopia, as SE of 1 D or more.


RESULTS
The mean age was 48 years (range, 22-84 years). The mean difference in SE between measurements before and after cycloplegia was 0.29 D (95% confidence interval, 0.28-0.31). The difference decreased with age and varied by refractive status for participants younger than 50 years, with the largest differences observed among young persons with hyperopic refractive errors. Across all age groups, agreement on classifications of refraction was high (84%-92%).


CONCLUSIONS
Overall, clinically inconsequential differences were observed between SEs before and after pharmacologic cycloplegia, suggesting that cycloplegia may not be necessary in epidemiological studies of refraction in adults.
Krantz
Elizabeth M
EM
Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, USA. krantz@episense.wisc.edu
Cruickshanks
Karen J
KJ
Klein
Barbara E K
BE
Klein
Ronald
R
Huang
Guan-Hua
GH
Nieto
F Javier
FJ
D000065:Accommodation, Ocular / Q000502:physiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015350:Contrast Sensitivity / Q000502:physiology; D004338:Drug Combinations; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage*; D010656:Phenylephrine / Q000008:administration & dosage; D011680:Pupil / Q000187:drug effects*; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000145:classification; D014331:Tropicamide / Q000008:administration & dosage; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
D004338:Drug Combinations; D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide