Purpose
The state of Maryland requires a vision evaluation either in person at the MVA, or performed by an eye care practitioner, for driver’s license renewal. Qualifications for an unrestricted driver’s license include binocular vision, Snellen visual acuity (VA) of at least 20/40 in each eye, and a continuous visual field (VF) of at least 140 degrees. We assessed how Maryland eye care practitioners approach completion of the vision screening form.
Methods
We obtained contact information for eye care practitioners in Maryland through the American Academy of Ophthalmology and the Maryland Board of Optometry. Eye practitioners who did not practice primarily in Maryland or who did not fill out at least one MVA vision screening form per month were excluded. The anonymous online survey comprised 25 questions covering demographics, VA, VF testing, and binocular vision screening.
Results
128 (23%) practitioners responded to 586 invitations. The majority of respondents were Caucasian (73%), male (66%), comprehensive (65%), and practiced in a suburban (69%), private practice (60%) setting. 62% of respondents completed between two and ten forms per month. Most respondents were able to identify the requirements of a VA >20/40 in each eye (86%) and a continuous visual field of 140 degrees (68%) for an unrestricted license. However, only 38% were aware of the binocular vision requirement. 74 % of respondents reported measuring the patient’s Snellen uncorrected VA to determine the need for corrective lenses. 73% assessed VF by confrontation with no difference between ophthalmologists and optometrists (p=0.37). Although 109 respondents perform automated perimetry, only 13 of them used automated perimetry results in filling out the form. 54% of participants assessed binocular vision; half using the stereo fly test.
Conclusions
A majority of a self-selected group of eye care practitioners in one state measure VA using a Snellen eye chart to determine whether acuity standards for a license renewal are met and whether refractive correction is necessary. VF is usually determined by confrontation. Binocular vision is only assessed half the time, and often with a test better suited to near vision. Regardless of practitioner adherence to the state-mandated criteria, there is a need to understand better the relationship between office measures of visual function and safe driving.
Keywords: 414 aging: visual performance •
754 visual acuity •
758 visual fields