Abstract
Purpose :
Emmtropization in infancy may be driven by peripheral defocus or by accommodation modulating axial length through changes in eye shape. Evaluating either of these mechanisms requires an accurate estimate of peripheral refractive error in infants. The purpose of this study was to determine the validity and repeatability of peripheral refractive error measurements using two instruments capable of measuring infants, the SureSight (Welch Allyn) and PowerRefractor (Plusoptix), in comparison with the gold standard Grand Seiko WR-5100K in order to determine the most suitable method for use in infants.
Methods :
Subjects were 21 adults (16 female) with an acuity of 20/25 or better in the right eye who had no history of ocular disease, active inflammation, ocular surgery, strabismus, or rigid contact lens wear. Measurements included cycloplegic (1% tropicamide) central and peripheral autorefraction at 30° and 20° temporal and nasal gazes of the right eye on the Grand Seiko WR-5100K (10 readings), SureSight (5 readings), and PowerRefractor (5 readings) in random order. Measurements were made at two visits separated by at least 24 hours. Measurement validity of the SureSight and PowerRefractor was assessed using paired t-test comparisons to the Grand Seiko WR-5100K. Measurement repeatability was assessed using 95% limits of agreement (LoA; 1.96 x SD of differences) between visits 1 and 2 for each gaze and instrument.
Results :
The SureSight measurements were not significantly different from the Grand Seiko WR-5100K in all gazes (p<0.65) while the PowerRefractor measurements were significantly different in four of the five gazes (p<0.042). The Sure Sight was within 0.25 ± 0.78 D of the Grand Seiko WR-5100K in all gazes while the PowerRefractor measured a more myopic refractive error than the Grand Seiko WR-5100K by as much as -0.97 ± 0.74 D (20° nasal gaze). There were no significant differences between visits for any instrument in any gaze (p<0.94). The 95% LoAs were between ±0.31 and ±1.5 D for the Grand Seiko WR-5100K, between ±0.38 and ±1.0 D for the SureSight, and between ±0.72 and ±1.7 D for the PowerRefractor.
Conclusions :
Based on both its validity compared to the Grand Seiko WR-5100K and its repeatability, the SureSight appears to be a reasonable choice as an autorefractor to use for peripheral refractive error measurement on infants.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.