Accuracy of the Welch Allyn SureSight for measurement of magnitude of astigmatism in 3- to 7-year-old children.
OBJECTIVE
To evaluate the accuracy of the Welch Allyn SureSight in noncycloplegic measurements of astigmatism as compared to cycloplegic Retinomax K+ autorefractor measurements of astigmatism in children from a Native American population with a high prevalence of high astigmatism.


METHODS
Data are reported for 825 3- to 7-year-old children with no ocular abnormalities. Each child had a Retinomax K+ cycloplegic measurement of right eye astigmatism with a confidence rating > or =8 and 3 attempts to obtain a SureSight measurement on the right eye.


RESULTS
SureSight measurement success rates did not differ significantly across age or measurement confidence rating (<6 vs > or =6). Ninety-six percent of children had at least 1 measurement (any confidence), and 89% had at least 1 measurement with confidence at the manufacturer's recommended value (> or =6). Overall, the SureSight tended to overestimate astigmatism. If the SureSight measurement had any dioptric value (0.00 D to 3.00 D), astigmatism of 2.00 D or less was likely to be present. If the SureSight showed astigmatism beyond the instrument's dioptric range (>3.00 D), Retinomax K+ measurements indicated that >2.00 D of astigmatism was present in 136 of 157 (86.6%). In cooperative children for whom the SureSight would not give a reading, 32 of 34 (94%) had >3.00 D of astigmatism.


CONCLUSIONS
The SureSight does not provide an accurate, quantitative measure of amount of astigmatism. However, it does allow accurate categorization of amount of astigmatism as < or =2.00 D, >2.00 D, or >3.00 D, and it has high measurement success rate in young children.
Harvey
Erin M
EM
Department of Ophthalmology and Vision Science, The University of Arizona, Tucson, 85711, USA. emharvey@u.arizona.edu
Dobson
Velma
V
Miller
Joseph M
JM
Clifford-Donaldson
Candice E
CE
Green
Tina K
TK
Messer
Dawn H
DH
Garvey
Katherine A
KA
D000367:Age Factors; D001251:Astigmatism / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D012029:Refraction, Ocular; D012044:Regression Analysis; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014787:Vision Tests / Q000295:instrumentation* / Q000592:standards*