The Effects of Visual Field Loss from Optic Disc Drusen on Performance in a Driving Simulator

Figures & data

Figure 1. Test point clusters in a 20° integrated visual field. Boxes marked (A) show the superior test points located within the central 10°. Boxes marked (B) show the inferior test points located within the central 10°. Boxes marked (C) show the superior test points located between 10° and 20°. Boxes marked (D) show the inferior test points located between 10° and 20°.

Table 1. Driving simulator data for male controls and patients with optic disc drusen.

	Controls	Optic disc drusen	p Value
Number	49	5
Mean age (years)	66	64	.33
Mean speed when city driving (km/h)	41	39	.33
Mean speed on the rural road (km/h)	81	76	.05
Mean speed on the motorway (km/h)	108	103	.09
Drivers with collisions	12%	20%	.62
Drivers with hazardous (0–1 m) FGW	2%	0%	1.25
Drivers with risky (1–2 m) FGW	22%	0%	1.76
Average critical (<1 s) THW events	4.2	2.4	.07
Average RT (s)	0.67	0.65	.74
Average LP when city driving (m)	0.0	−0.2	<.05
Average LP on the rural road (m)	0.0	−0.1	.42
Average LP on the motorway (m)	0.0	0.3	.06

FGW: failed to give way; LP: lateral position compared with controls (- to the right, + to the left); THW: time headway; RT: reaction time.

Table 2. Results and mean age for 334 participants with visual field loss for different reasons that undertook a simulated driving test at the Swedish National Road and Transport Research Institute, Linköping, during 2016–2018.

Disease		n	Mean age	Percentage who passed
Stroke		153	62	65
Glaucoma		104	69	71
Diabetes		27	60	56
Brain lesions (except stroke)		22	46	68
	Trauma	7	48	71
	Tumours	7	43	57
	Malformations	8	47	75
Optic nerve lesions (except glaucoma)		9	64	89
	Optic disc drusen	5	64	100
	Optic nerve infarction	3	60	100
	Optic neuritis	1	72	0
Retinal lesions (except diabetes)		10	53	80
	Dystrophy	5	51	100
	Amotio	3	47	67
	Age-related macular disease	2	66	50
Other		9	68	67
Total		334	63	67

Table 3. Comparison of mean sensitivity in different clusters of the integrated visual field for male participants with glaucoma who failed the simulator test and participants with optic disc drusen who passed the test.

		Failed glaucoma n = 20	Passed optic disc drusen n = 5	p Value
Mean age (years)		74	64	.00
IVF mean sensitivity (dB)
	Central (A + B)	19.8	22.1	.18
	Peripheral (C + D)	19.4	14.7	<.05
	Central superior (A)	18.1	21.6	.22
	Central inferior (B)	19.0	16.2	.22
	Peripheral superior (C)	21.4	22.7	.37
	Peripheral inferior (D)	19.8	13.2	<.05

A-D: visual field clusters according to Figure 1; IVF: integrated visual field.

Figure 2. Perimetric examinations with binocular Esterman (left) and 24-2 Humphrey or Octopus G-standard (right) for the five participants with visual field loss from optic disc drusen.