Does using a bioptic telescope improve visual recognition of the on-road environment?

SIGNIFICANCE: Individuals with reduced visual acuity (VA) may drive with bioptic telescopes in some jurisdictions. The effect of bioptic telescope use on on-road recognition distances is important for driving safety, as increased recognition distances increase the time available to react to road signs or driving events. PURPOSE: This study aimed to investigate the impact of bioptic telescope use on visual recognition of road signs, traffic lights, and hazards in an on-road driving environment in individuals with reduced VA. METHODS: Ten individuals (mean ± standard deviation age, 39.1 ± 19.1 years) with reduced VA (trained to use bioptic telescopes) participated in a repeated-measures on-road experiment for two viewing conditions, with and without a bioptic telescope (randomized order). Participants underwent a clinical low vision assessment, including high-contrast VA with and without the bioptic telescope aligned, visual fields, and contrast sensitivity testing. For the driving component, participants seated in the front passenger seat of a moving car reported all road signs, traffic lights, and hazards (unpredictable road events that represent a risk to driving safety including other vehicles, cyclists, pedestrians) seen along a route that included suburban roads and highways. Video cameras captured participants' viewing behavior, verbal commentary, and the distance at which three pre-selected road signs were reported. RESULTS: In the eye with the bioptic telescope, high-contrast VA improved from 0.75 ± 0.17 (without) to 0.25 ± 0.1 logMAR with the bioptic telescope. Bioptic telescope use did not affect the percentage of road signs, traffic lights, or hazards correctly recognized but did result in 2.6 times longer recognition distances (49 ± 23 vs. 19 ± 11 m, t9 = 5.02, p<0.001). CONCLUSIONS: Road signs were recognized at significantly longer distances when using a bioptic telescope, confirming their positive impact on timely visual recognition of objects within the driving scene. Future work should explore whether this effect generalizes to individuals using bioptic telescopes when driving a vehicle.

Views and practices of Australian optometrists regarding driving for patients with central visual impairment.

BACKGROUND: Eye-care practitioners are often required to make recommendations regarding their patients' visual fitness for driving, including patients with visual impairment. This study aimed to understand the perspectives and management strategies adopted by optometrists regarding driving for their patients with central visual impairment. METHOD: Optometrists were invited to participate in an online survey (from April to June 2012). Items were designed to explore the views and practices adopted by optometrists regarding driving for patients with central visual impairment (visual acuity [VA] poorer than 6/12, normal visual fields, cognitive and physical health), including conditional driver's licences and bioptic telescopes. Closed- and open-ended questions were used. RESULTS: The response rate was 14 per cent (n = 300 valid responses were received). Most respondents (83 per cent) reported that they advised their patients with visual impairment to 'always' or 'sometimes' stop driving. Most were confident in interpreting the visual licensing standards (78 per cent) and advising on legal responsibilities concerning driving (99 per cent). Respondents were familiar with VA requirements for unconditional licensing (98 per cent); however, the median response VA of 6/15 as the poorest VA suggested for conditional licences differed from international practice and Australian medical guidelines released a month prior to the survey's launch. Few respondents reported prescribing bioptic telescopes (two per cent). While 97 per cent of respondents stated that they discussed conditional licences with their patients with visual impairment, relatively few (28 per cent) reported having completed conditional licence applications for such individuals in the previous year. Those who had completed applications were more experienced in years of practice (p = 0.02) and spent more time practising in rural locations (p = 0.03) than those who had not. CONCLUSION: The majority of Australian optometrists were receptive to the possibilities of driving options for individuals with central visual impairment, although management approaches varied with respect to conditional licensing.