Rates of Progressive Visual Field Loss and Driving Performance in Glaucoma

Abstract

Purpose : To evaluate the association between rates of progressive visual field loss and longitudinal changes in driving performance in glaucoma patients followed over time.

Methods : This was a prospective observational cohort study involving 93 patients with glaucomatous visual field loss followed for an average of 3.7 ± 0.9 years. Rates of visual field change were estimated using the standard automated perimetry (SAP) mean sensitivity (MS) of the integrated binocular visual field. Driving performance was longitudinally evaluated using a curve negotiation task, where subjects were instructed to drive in the center lane of a winding 3-lane road. The driving simulator was used to test ability to attend simultaneously to a central and a peripheral task, or ability to divide attention. Curve coherence was used as a parameter to measure the central task performance. Divided attention was evaluated by measuring reaction times to peripheral stimuli presented in the simulator screen. Curve coherence values were negatively skewed and mean reaction time values were positively skewed, therefore the natural logarithm (ln) was calculated for further analysis. Joint longitudinal mixed models were used to investigate the association between rates of change in SAP MS over time and longitudinal change in driving performance while adjusting for confounding factors.

Results : Progressive visual field loss was associated with longitudinal decline in the ability to negotiate a curve. Each 1 dB/year faster loss of binocular MS was associated with 0.094 natural logarithm (ln) unit/year decline in curve coherence (P<0.001; R²=22.8%). Progressive visual field loss was also associated with longitudinal increase in mean reaction time on the divided attention task. Each 1 dB/year faster loss was associated with 0.097 ln unit/year increase in mean reaction time (P<0.001; R²=69.2%). In the multivariable models adjusting for confounding factors, progressive visual field loss was still significantly associated with decline in curve coherence and with increase in mean reaction time in the divided attention task over time. Each 1 dB/year faster loss of binocular MS was associated with 0.167 ln unit/year decline in curve coherence (P<0.001) and with 0.090 ln unit/year increase in mean reaction time (P<0.001).

Conclusions : Fast visual field progression in glaucoma patients was associated with worsening driving performance over time as assessed by a simulator.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.