Abstract
Purpose :
Uncorrected refractive errors are the leading cause of visual impairment globally and are particularly prevalent in low-resource countries. One of the primary barriers to affordable and quality vision care in these countries is the limited number of eye care professionals with necessary skills to reliably refract a patient. To that end, providing a method of refraction which is reliable, accurate and precise, yet is easy to use by a relatively unskilled operator could have a significant impact on reducing the incidence of uncorrected refractive errors in both developed and developing economies.
Methods :
A newly designed hand-held Shack-Hartman based wavefront sensor was used to repeatedly measure the ocular refraction of 16 normal subjects free from ocular disease or surgery. Undilated subjective refractions were performed by optometrists, while the dilated autorefraction was measured by an optometric staff member using a commercial autorefractor (Tomey RT-7000) and the hand-held wavefront sensor prototype. Subjective refraction was performed once only, while 5 measurements were performed using each autorefractor in an alternating fashion. Subjects ranged in age from 20 to 60 years old (mean ± standard deviation = 43 ± 12) with 8 males and 8 females.
Results :
Significant correlations were observed between the hand-held wavefront sensor prototype and subjective refraction for both sphere (R = 0.988, p < 0.05) and cylinder (R = 0.714, p < 0.05). Significant correlations were also observed between the hand-held wavefront sensor and the commercial autorefractor for both sphere (r = 0.992, p < 0.05) and cylinder (R = 0.832, p < 0.05). The correlation between the autorefractor and subjective refraction was also significant for both sphere (r = 0.992, p < 0.05) and cylinder (R = 0.565, p < 0.05).
Conclusions :
The hand-held wavefront sensor was demonstrated to produce accurate refraction measurements in normal adult subjects with high correlation to a conventional commercial autorefractor. A trained non-clinician can rapidly make measurements with minimal patient input. This is valuable for examinations performed outside office settings such as those often encountered in countries with low levels of trained ophthalmic clinicians.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.