Characteristics of On-Road Driving Performance of Persons With Central Vision Loss Who Use Bioptic Telescopes

Abstract

PURPOSE.To compare the on-road driving performance of visually impaired drivers using bioptic telescopes with age-matched controls.METHODS. Participants included 23 persons (mean age ¼ 33 6 12 years) with visual acuity of 20/63 to 20/200 who were legally licensed to drive through a state bioptic driving program, and 23 visually normal age-matched controls (mean age ¼ 33 6 12 years). On-road driving was assessed in an instrumented dual-brake vehicle along 14.6 miles of city, suburban, and controlled-access highways. Two backseat evaluators independently rated driving performance using a standardized scoring system. Vehicle control was assessed through vehicle instrumentation and video recordings used to evaluate head movements, lane-keeping, pedestrian detection, and frequency of bioptic telescope use.RESULTS. Ninety-six percent (22/23) of bioptic drivers and 100% (23/23) of controls were rated as safe to drive by the evaluators. There were no group differences for pedestrian detection, or ratings for scanning, speed, gap judgments, braking, indicator use, or obeying signs/signals. Bioptic drivers received worse ratings than controls for lane position and steering steadiness and had lower rates of correct sign and traffic signal recognition. Bioptic drivers made significantly more right head movements, drove more often over the right-hand lane marking, and exhibited more sudden braking than controls.CONCLUSIONS. Drivers with central vision loss who are licensed to drive through a bioptic driving program can display proficient on-road driving skills. This raises questions regarding the validity of denying such drivers a license without the opportunity to train with a bioptic telescope and undergo on-road evaluation.

Current Perspectives of Bioptic Driving in Low Vision

“…13,19 In Owsley's recent investigation, the majority of a sample reported using their device to improve driving performance, contrary to this proposed belief. 2 Likewise, in a previous study, it was noted that more than half of the bioptic drivers observed were frequently utilising the telescope for spotting while driving.…”

“…2 Likewise, in a previous study, it was noted that more than half of the bioptic drivers observed were frequently utilising the telescope for spotting while driving. 19 Recent investigations seem to emphasise the importance of assessing the comprehensive individual in regards to not only their visual function but also their visual processing, cognitive, and motor functions. These factors in addition to other contextual factors such as the patient's age and medical history provide a more complete picture in determining the risk level for driving.…”

Characteristics of on-road driving by persons with central vision loss: Learning to drive with a bioptic telescope

“…In that study, 23 of the bioptic drivers were already licensed through the State of Alabama’s bioptic licensure program; this data have already been published (Owsley, et al, 2014; Wood, et al, 2013). We also evaluated the five drivers being seen in the clinic who had learner’s permits at the time of the study but had never been licensed to drive either with or without a bioptic telescope (henceforth known as “trainees”); this paper compares the driving performance data of these trainees with that of the licensed bioptic drivers.…”

“…A detailed description of the assessment procedures involved in this study are provided elsewhere (Wood, et al, 2013). In brief, demographic information was obtained by medical record review and confirmed by interview by trained staff, while a modified Driving Habits Questionnaire was used to obtain information about licensure, characteristics of the driver’s bioptic telescope, years of wear, training and the primary cause of vision impairment; this information was also confirmed through their eye medical record.…”

“…In the only recent study (Vincent, et al, 2012), crash risk was not significantly different between a group of bioptic drivers and either a comparison group matched in terms of license restrictions or the regional population. Recently, in the first experimental study to assess the driving performance of licensed bioptic drivers relative to controls, the majority (22/23) of the bioptic drivers were rated as safe to drive by the backseat evaluators and by a certified driver rehabilitation specialist (CDRS) (Wood, McGwin, Elgin, Searcey, & Owsley, 2013). In addition, while the bioptic drivers displayed some minor deviations in lane position, steering steadiness and road sign recognition, they were indistinguishable from the control drivers in many other driving skills including pedestrian detection, speed, gap judgments, braking, and obeying signs.…”