Purpose
In approximately 40 US states, drivers who cannot meet vision standards with conventional optical correction are permitted to use bioptic telescopic spectacles to obtain licensure. Very few studies of safety of bioptic driving have been conducted. This study examined the relationships among visual and demographic factors and motor vehicle collisions (MVC) in bioptic drivers in Ohio.
Methods
A retrospective study of patients identified as having received an initial daylight bioptic examination at the College of Optometry at the Ohio State University was conducted. Data were collected on vision, including visual acuity (logMAR charts), contrast sensitivity (Pelli Robson or Mars charts) and visual field (arc or Goldmann perimeter). Driving records from the Ohio BMV were obtained and demographics, ocular diagnoses, and licensure history were also recorded. Relationships among vision, demography, and BMV data including MVC were investigated using survival analysis and the Cox proportional hazards regression model.
Results
238 drivers (65% male) were identified. Age at initial exam ranged from 16 to 81 years (mean = 39±15 years). Time since bioptic licensure ranged from 1 to 22 years (mean = 10±5 years). Mean logMAR visual acuity OU was 0.76±0.12 (approximately 20/115) and mean log contrast sensitivity was 1.53±0.23. A total of 292 MVC were documented in the BMV records for these drivers. The number of MVC per driver ranged from 0 to 11, with 124 (52%) drivers having had at least one MVC and 72 (30%) having had two or more. Visual acuity, contrast sensitivity, and horizontal visual field were not significant predictors of MVC (p = 0.81, 0.18, and 0.76, respectively). Gender was not associated with MVC (p=0.28), but age was associated with fewer MVC (p < 0.001). Previous (without-bioptic) licensure status was associated with fewer MVC (p < 0.001), with 41% of drivers with previous licensure involved in an MVC versus 67% of drivers without previous licensure.
Conclusions
Age and previous non-bioptic licensure were inversely associated with fewer MVC in this group of bioptic drivers. VA, CS, horizontal VF, and gender did not predict MVC involvement.