1

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Subject: Submission to National Transport Commission. Rail Workers Safety

Review

Submitted by: Medmont International Pty Ltd Unit 5 56 Norcal Rd, Nunawading

VIC 3131

Date: 05/01/2014

Author: Tony Gibson (consultant optometrist) MSc Optom, LOSc, FACO,

OAM CASA credentialled Optometrist (3189)

Background:

Medmont International Pty Ltd manufactures a number of instruments used in the ophthalmic

industry, including an automated computerised static perimeter, model M700, used to assess visual

fields. The M700 is widely used in Australia by optometrists and ophthalmologists.

There are a number of other computerised perimeters available, such as Humphrey Visual Field

Analayser (Carl Zeiss Pty Ltd), Octopus perimeter and Optimed. The Humphrey HFVA and Medmont

M700 are the most common automated perimeters used in Australia. Most automated perimeters

produce visual field tests based on controlled viewing conditions using validated testing algorithms

and results obtained are comparable for a given patient. In particular, there is good data comparing

the Humphrey HFVA and the Medmont M700.

The author is a clinical optometist in practice for 45 years, has provided clinical advice and general

consultant opinion to Medmont in the past. He has an interest in visual ergonomics and has been

used as a consultant to the CASA Aviation Medical Unit.

The Current Problem:

Aust Roads and the National Transport Commission publish the guideline document “Assessing

Fitness To Drive For Commercial And Private Vehicle Drivers” (March 2012) which is endorsed and

used by Australian driving regulatory authorities.1 Section 10 describes vision and eye disorders.

Section 10.2.3 Visual Fields provides a definition of visual fields and discusses assessment methods.

In the second paragraph the last 2 sentences are as follows:

“If the automated perimetry suggests that the requirements for an unconditional licence are not met,

then the field test should be performed. While opinions on fitness to drive can be based on testing

fields for each eye separately the Esterman binocular field is the preferred method of assessment.”

Section 10.3 defines normal fields Driving licences as follows:

Private Unconditional

Binocular: 110˚horizontal ± 10˚vertical above and below the horizontal midline

Monocular: Any significant loss (scotoma) within a central radius of 20˚ from the foveal

fixation or other scotoma likely to impede driving performance

2

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Private Conditional

Licence may be granted subject to a report from treating optometrist or ophthalmologist and

subject to annual review

Monocular persons adapted to their condition as above but subject to two year review

Commercial Unconditional

No visual field defect

Commercial Conditional

Binocular: 140˚horizontal ± 10˚vertical above and below the horizontal midline

Monocular: Any significant loss (scotoma, hemianopia, quadrantopia) likely to impede

driving performance

Licence may be granted subject to a report from treating optometrist or ophthalmologist and

subject to annual reviw.

The specific reference to Esterman binocular visual field as a preferred or superior test is

anecdotal, has poor supporting evidence, devalues better tests and implies a potential

bias to some perimeter manufacturers.

Comment:

Measurement of Normal Visual Fields:

The extent of a normal visual field is approximately 180° horizontal x 120° vertical.

Commonly accepted standards of visual fields considered safe for driving refer to normal within

110˚horizontal ± 10˚vertical and no significant central losses. 1

Automated static perimetry is regarded clinically as the best technique available to measure visual

fields.

Most automated perimeters produce visual field tests based on controlled viewing conditions using

validated testing algorithms and results obtained are comparable for a given patient. The extent and

sensitivity of the patients measured visual field can be used to diagnose and monitor conditions that

affect the complete visual pathway.

Clinically useful visual fields are typically measured using

monocular viewing over the central 50 to 100˚field

thresholding methods sensitive to patient responses

an assessment of patient reliability by recording fixation or response errors

comparison to previous results or inbuilt age normal reference databases

analysis of rate of progression and /or prediction of future losses

Most perimeters use a central fixation point and test to ±50˚ from fixation or 100˚ overall field. 2 The

area tested can be extended by moving the fixation point during the test.

Ancillary tests include binocular threshold and supra threshold screening tests, or in the case of a

binocular dysfunction, the proportion of the field in which the subject can maintain single vision.

3

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Results can also be exported for further analysis using specialised software to combine monocular

results and simulate the extent of a combined or integrated binocular field

Visual fields measured on well designed and validated automated perimeters are comparable. In

particular there is good data comparing the Humphrey HFVA and the Medmont M700. 3

An expanded description of perimetry methods is decribed in Appendix 1

Visual Fields and Driving

The evidence linking visual field losses and driving capacity is controversial. There are a number of

studies linking both monocular and binocular visual field assessment and driving ability. Many rely

on the results of an Esterman binocular visual field and often fail to demonstrate a link between

results and driving capacity. 5

Esteman Suprathreshold Field Parameters

The Esterman test was first developed using visual fields determined by manual kinetic perimeters. It

was used to describe the effect of visual field loss on general mobility and the testing protocol tested

sensitivity over a wide horizontal field with a bias to the inferior field but effectively ignored the

central 20°. 2,4

The Esterman visual field test (EVFT) was adapted to static automated perimetry particularly the

HFVA.2 Other perimeters have similar test protocols incorporated into their software. A similar

pattern of test targets are presented binocularly to the patient at suprathreshold high contrast levels

with limited or no control of initial fixation. Medmont for instance has included the Medmont

Binocular Driving Test which has equivelent test coverage, stimulus density and sensitivity as the

EVFT.

The test is of limited clinical use, but has been adopted as an approximation of the patients “real

field of view” and advocated to be more relevant in terms of functional ability. The test is relatively

quick and has been commonly applied to assess occupational or driving capacity.

The early availability of the EVFT on the HFVA perimeter has created an impression that this

perimeter is the only one capable of doing the test.

The HFVA EVFT test parameters are as follows:

Bright suprathreshold (10 dB) targets are presented at 120 points in the predominantly

horizontal field.

There are few targets in the central ±20°, with 12 locations examined above the midline and

22 below, and no stimuli within ±7.5° of fixation.

The patient is free to move both eyes and can anticipate where the next target may be

located

Responses are recorded as seen or not seen and there is no thresholding of any targets

There is no capacity to record fixation losses

The Esterman Efficiency Score (EES) is the percentage of stimuli seen and biased towards the

inferior visual field due to the greater density of stimuli within this area.

4

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Scores are typically clustered at high levels (>80%) and it is difficult to fail as central field

losses are often missed

Esterman Suprathreshold Test Limitations

Despite the limitations of the evidence linking Esterman test results and driving capacity, it has

persisted as a default test for determining driving and occupational capacity. 5

Specific features and limitations with the test include

Use of suprathreshold targets and free fixation from both eyes simultaneously

Fast test speed and convenience, fewer opportunities to fail patient

Poor measures of patient reliability

Poor sensitivity and clustering of high pass scores

Passes patients with recognised significant monocular field defects including dense arcuate

and hemifield losses

Contraversial and varied acceptance of test as a predictor of driving capacity.

Perception that the test can only be performed on the Humphrey Visual Field Analyser.

(The Esterman title for the test may be copyrighted and commercially limited to the HFVA

manufacturer)

Similar test protocols are available on other perimeters but less well recognised by

regulators conditioned to accept Esterman test results only

The most significant and obvious concern is the disparity between obvious poor monocular test

results and the overly optimistic Esterman result.

Regulators have been in the past forced to decide on specific cases where ophthalmic consultants

have provided reports that considered a good result on Esterman as superior to a poor result from

the monocular threshold field and recommended patients as operationally safe to perform specific

tasks such as flying or driving.

Such conflicting opinions are often anecdotal and not supported by good evidence.

The gold standard of care to determine visual field changes requires regular monocular thresholded

tests

Clinical use of an Esterman Field test only to detect or monitor progression of visual field losses

without also using monocular threshold tests would be unlikely and be regarded as negligent.

5

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

NTC Visual Field Guidelines

The existing NTC guidelines perpetuate an impression that the Esterman test is a superior visual field

test when assessing driving capacity. There is minimal evidence available to support this view.

Guidelines should be evidence-based. New studies have recognised the limitation of Esterman test

and suggest that integrated monocular threshold field tests may be more sensitive predictors of

driving capacity.4

Some commercial software is available and utilises existing monocular test results to create

simulated binocular threshold tests. 4

New perimeters are now capable of threshold testing of binocular fields with various controls of

fixation and the results may be more useful in predicting the effect of visual field loss on operational

task capacity.

The Civil Aviation Safety Authority of Australia has recently recognised the limitations of opinions based on Esterman test results.1 Adequate field testing is defined in their guidelines as “50+ degree monocular visual field testing. (Esterman binocular field not acceptable) Medmont binocular field test with fixation is acceptable”. Normal field test results require “no overlapping field defect, no defect within 20 degrees of the visual axis and total field loss less than one quadrant”

Suggested Solution

The new guidelines should continue to describe visual fields, assessment methods and continue to

recommend automated visual field analysis using currently commercially available and tested

perimeters.

References to specific perimeters or testing protocols should be generic and inclusive. An examining

professional will form an opinion based on a number of tests regarding a licence applicant’s ability to

operate safely. The guidelines should direct the examiner to determine which tests are regarded as

providing acceptable evidence to support such an opinion.

The current guidelines can be easily modified by replacing specific references to Esterman binocular

field tests with generic statements to read as follows:

Monocular automated perimetry is the best method to measure field loss significant enough to

establish if the requirements for an unconditional licence are met.

If a significant monocular loss is found, then a binocular threshold field test should be performed

or simulated by integrating existing monocular threshold results.

Fixed intensity suprathreshold binocular field tests (eg Esterman Visual Field Test and Medmont

Binocular Driving Test) may provide a general indication of peripheral perception but will not be

considered alone as a valid test of capacity to drive

Impact of Suggested Solution

The NTC guidelines will be upgraded to reflect evidence based opinion and be consistent with those

recommended by other regulators such as CASA

The removal of the Esterman reference should overcome the limitations listed in this report

6

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Appropriate Visual Field reports from all commercially available perimeters should be accepted as

valid

More comprehensive testing and reports will be required to justify conditional licencing

Applicants seeking testing and reports to support a case for conditional licencing should be advised

that they may be charged appropriate fees for this service

Manufacturers may be stimulated to provide suitable software changes or hardware upgrades to

either provide practical binocular threshold testing or allow existing monocular tests to be

integrated into a binocular result.

7

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Appendix 1 PERIMETRY METHODS. 2,3,4,5,

Kinetic Perimeters

Visual fields were measured in the past kinetically with an observer presenting moving fixed size and

brightness targets from a non-seen to seen area.

A simple confrontation test was used with various targets presented monocularly to a patient

seated opposite the teter who presented various targets in the four quadrants of the patients vision.

A small target could be used to elicit the blindspot.

Bjerrum Fields used a black background screen at 1 m from the observer with a darkened observer

presenting white targets of various sizes using a small wand. While the test may have been sensitive

for a given patient and observer technique inter test comparisons were not reliable.

Hemispherical perimeters were used to test peripheral fields. The Goldmann perimeter was the best

developed of these and presented projected targets of known size and contrast against a standard

background. The observer viewed the patient through a small telescope and recorded when the

patient reported seeing a target moved from a non-seeing to seeing area. Points were plotted on

paper and represented topographically as zones of equal vision.

Some observer skill was required to record field losses reliably. Kinetic visual fields are rarely used

now other than for preliminary screening.

Automated Perimeters

Automated static perimeters present small lit targets in a testing bowl with controlled viewing

conditions and computerised control of the target location, contrast and size. Most perimeters use a

central fixation point and test to ±50˚from fixation or 100˚ overall field. The subject’s results can be

analysed for changes over time and compared to an age matched normal range of responses.

The subject is required to fixate a central target in a uniformly lit bowl field. Other targets are

presented briefly, one at a time, at random and at a variety of locations in a pre-selected grid. The

subject is instructed to press a response button when the targets are seen. The software then

reduces the target contrast until there is no response, i.e. they are not seen. The target brightness is

adjusted in a staircase mode according to patient response. A 50% threshold brightness is recorded

when the response oscillates between targets seen and not seen.

This value represents the target contrast at a given point which the subject might see on 50% of

occasions and is measured in decibel (dB) units.

The task is a sensitive psychophysical test and requires an alert co-operative subject to respond

appropriately.

Subject reliability is measured by: fixation losses (the number of times they were measured not looking at the aiming target); false positives(the number of times the response button was pressed when a target was not

present);

8

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

false negatives (the number of times they did not respond to target already seen at a lower

contrast).

A patient database is established to allow repeated field tests over time to determine if there is any

progressive change. Sophisticated software presents targets in a random pattern with standard

viewing conditions and provides the ability to match aged based norms. Printouts show field losses

using numerical and grey scales; the darker areas representing more extensive field loss and lighter

areas indicating points seen, graded by sensitivity.

Each perimeter has its own presentation and software designs and have undergone validation and

reliability testing. Well controlled studies have shown that results from different perimeters are

directly comparable and convertible to to establish and reliably document visual field changes .

The development of computer controlled static perimeters improved the reliability of measurement

of visual fields and has been clinically accepted for many years as the clinical “gold standard” for

detecting and monitoring changes in visual field loss.

9

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

REFERENCES and BIBLIOGRAPY SORTED BY TOPIC

1. VISUAL FIELD STANDARDS

VISION REQUIREMENTS for DRIVING SAFETY – International Council of Ophthalmology – February 2006, Available at: www.icoph.org/standards.

Assessing Fitness to Drive for commercial and private vehicle drivers. Medical standards for licensing and clinical management guidelines. 2012 Available at www.austroads.com.au

Vicroads Visual Impairment Guide. 2015(Jan) : available at www.vicroads.vic.gov.au/licences/medical-conditions-and-driving/medical-conditions

DVLA current medical guidelines for professionals- Vision Appendix. 2013(Aug); available at www.gov.uk/government/organisations/driver-and-vision-licensing-agency

Civil Aviation Safety Authority DAME Clinical Practice Guidelines/ Glaucoma/Ocular hypertension. Available at www.casa.gov.au/SCRIPTS/NC.DLL?WCMS:STANDARD::pc=PC_101521

2. VISUAL FIELDS AUTOMATED PERIMETRY

The physiological basis for perimetry. In Automated perimetry in glaucoma. A practical guide. Drance

SM, Anderson DR (eds), 1985. Grune & Stratton, Orlando, USA.

Heijl A. The Humphrey Field Analyser, construction and concepts. Doc Ophthalmol Proc Ser 1985; 42:

77-84.

Esterman, B. Grid for scoring visual fields. 1. Tangent screen. Arch Ophthalmol., 1967; 77:780-786.

Esterman, B. Grid for scoring visual fields. 2. Perimeter. Arch Ophthalmol., 1968; 79:400-406.

Esterman, B. Functional scoring of the binocular field. Ophthalmology, 1982; 89:1226-1234. ISLRR

3. VISUAL FIELDS PERIMETER VALIDATION, COMPARISONS

Humphrey Field Analayser 11-i User Manual, 2005

Vingrys AJ, Helfrich KA. The Opticom M-600: a new LED automated perimeter. Clin Exp Optom 1990;

73: 3-17.

Pye D, Herse P, Nguyen H et al. Conversion factor for comparison of data from Humphrey and

Medmont automated perimeters Clin Exp Optom 1999; 82: 11-13

Landers J, Sharma A, Goldberg I, Graham S. A comparison of perimetric results with the Medmont

and Humphrey perimeters. Br J Ophthalmol. 2003 Jun;87(6):690-4.

Vingrys, A Report M1.01, M1.08 The Medmont Binocular Driving Field Test, Jan 2001 , Comments

regarding the DVLA objections to the M700 Driving test June 2001 File Reports commisioned by

Medmont Pty Ltd to Department of Optometry & Vision Sciences University of Melbourne, Australia.

Reprint request to Medmont Pty Ltd

Anderson DR, Fener WJ, Alward WLM, Skuta GL. Threshold equivalence between perimeters.

Ophthalmology 1989; 107: 493505.

Heuer DK, Anderson DR, Feuer WJ, Gressel MG. The influence of decreased retinal illumination on

automated perimetric threshold measurements. Amer J Ophthalmol 1989; 108: 643-650.

10

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Wood JM, Wild JM, Bullimore MA, Gilmartin B. Factors affecting the normal perimetric profile

derived by automated static perimetry. I. Pupil size. Ophthal Physiol Opt 1988; 8: 26-31.

Artes, P, O’Leary,N, Hutchison, D, Heckler, L, Sharpe, G, Nicolea, M, Chauhan, B. Properties of the

Statpac visual field index, Invest Ophthalmol Vis Sci 2011; 52(7) 4030-4038

Starita RJ, Fellman RL, Lynn JR. Static automated perimetry: background luminance and global visual

field indices in the quantification of normal, suspect and glaucomatous visual fields. Invest

Ophthalmol Vis Sci 1987; 28 (Suppl): 269.

4. VISUAL FIELDS BINOCULAR & SIMULATIONS

Crabb DP, Viswanathan AC, McNaught, A, Poionoosawmy B, Fitzke,F, Hitchings, R. Simulating

binocular visual field status in glaucoma. Br J, Ophthalmol 1998; 82:123–124

Crabb DP, Viswanathan AC, Integrated Visual Fields: a new approach to measuring the binocular

field of view and visual disability. Grafes Arch Clini Exp Ophthalmol. 2005 March, 243(3); 210-216

Campell H, Friedman D, Quigley H, Miller R . Correlation of the binocular visual field with patient

assessment of vision. Invest Ophthalmol.Vis, Sci. 2002, April, 43 (4), 1059 – 1067

Arora K, Bolland M, Friedman D, Jefferys J, West S, Ramulu, P . The relationship between better eye

integrated visual field mean deviation and visual disability. Ophthalmology 2013(Dec); 120(12):

2476– 84

Jampel H, Friedman D, Quigley H, Miller R. Correlation of the binocular field with patient assessment

of vision. Invest Ophthalmol Vis Sci. 2002; 43(4): 1059-1065.

4. VISUAL FIELDS AND MOBILITY

Brown B, Brabyn L, Welch L, et al. Contributions of vision variables to mobility in age-related

maculopathy patients. Am J Optom Physiol Opt. 1986; 63: 733-739.

Lovie-Kitchin J, Mainstone J, Robinson J, et al. What areas of visual field are important for mobility in

low vision patients? Clin Vision Sci. 1990; 5: 249-264.

Marron JA, Bailey IL. Visual factors and orientation mobility performance. Am J Optom Physiol Opt.

1982; 59: 413-426.

Quigley HA. Mobility performance in glaucoma. Invest Ophthalmol Vis Sci. 1999; 40: 2803-2809.

Jampell H, Glaucoma patient’s assessment of their visual function and quality of life. Trans Am

Ophthmol Soc. 2001; 99: 301-307

Jampel H, Friedman D, Quigley H, Miller R. Correlation of the binocular field with patient assessment

of vision. Invest Ophthalmol Vis Sci. 2002; 43(4): 1059-1065.

Mills R, Drance S. Esterman disability rating in glaucoma. Ophthalmology, 1986 March, 93(3): 371-

378

5. VISUAL FIELDS AND DRIVING

11

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Assessing Fitness to Drive for commercial and private vehicle drivers. Medical standards for licensing and clinical management guidelines. 2012 Available at www.austroads.com.au Vicroads Visual Impairment Guide. 2015(Jan) : available at

www.vicroads.vic.gov.au/licences/medical-conditions-and-driving/medical-conditions

DVLA current medical guidelines for professionals- Vision Appendix. 2013(Aug); available at

www.gov.uk/government/organisations/driver-and-vision-licensing-agency

Johnson CA and Keltner J (1983) “Incidence of visual field loss in 20,000 eyes and its relationship to

driving performance” Arch Ophthalmol ; 101: 371-375

Owsley C, McGwin G. Vision impairment and driving . Survey Ophthalmol 1999; 43(6) 535-550

Racette L, Casson EJ. The impact of visual fiield loss on driving performance: evidence from on-road

driving assessments. Optm Vis Sci. 2005 Aug;82(8): 668-74

Crabb DP, Fitzke FW, H, itchings RA, Vizwanathan PC. A practical approach to measuring the visual

field component of fitness to drive. Br. J Ophthmol, Sep 2004; 88 (9): 1191–1196

Kasnecki, E, Sippel, K, Aehling, K, Heister, M, Rosentsteil, W, Schiefer, U, Papergeorgiou, E. Driving

with binocular field loss ? A study on a supervised on-road parcours with simultaneous eye and head

tracking. PLOS ONE, 2014. Feb 9(2), EH7470, 1–12

Fahmy I, , Mitwally, F, Fouly M. The value of Esterman binocular field testing in issuing drivers licence

for glaucoma patients. Nature and Science, 2011:9 (5) 109 – 118

Alaya, M . Comparison of the monocular Humphrey visual field in the binocular Humphrey Esterman

visual field test for driver licensing in glaucoma subjects in Sweden, BMC Ophthalmology (2012)

12:35

Medeiros, F, Weinreb, R, Boer, E, Rosen, P. Driving simulation as a performance-based test of visual

impairment in glaucoma. J glaucoma 2012 Apr-May;21(4): 221–227

Rubin, G, Ng, E, Bandeen-Roche K, Keyl P, Freeman E, West S . A prospective population-based study

of the visual impairment in motor vehicle crashes amongst older drivers: The SEE study. Invest

Ophthalmol Vis Sci 2007; 48(4) 1483-1491

Haymes, S, LeBlanc R, Nicolea M, Chiasson L, Chauhan B. Risk of falls in motor vehicle collisions in

glaucoma. Invest Ophthalmol Vis Sci 2007; 48(3) 1149-1155

McGwin G, , Xie A, Mays A, Joiner W, DeCarlo D, Hall T, Owsley C. Visual field defects in the risk of

motor vehicle collisions among patients with glaucoma. Invest Ophthalmol Vis Sci 2005

Haymes, S, LeBlanc R, Nicolea M, Chiasson L, Chauhan B. Glaucoma and on road driving

performance. Presentation ARVO, 2007(May)

Owsley C. Vision and driving in the elderly. Optom Vis Sci, 1994, 71, 727-35.

Van Rijn LJ, Wilhelm H, Emesz M, Kaper R, Heine S, Nitsch S, Grabner G, Völker-Dieben HJ. Relation

between perceived driving disability and scores of vision screening tests. Br J Ophthalmol., 2002, 86,

1262-64.

Crabb DP, Fitzke FW, Hitchings RA and Viswanathan, AC. A practical approach to measuring the

visual field component of fitness to drive. Br J Ophthalmol. 2004; 88:1191-1196

12

HEAD OFFICE

Medmont International Pty Ltd Unit 5 56 Norcal Rd Nunawading Vic 3131, Australia ABN: 93 154 326 600

MAIN

+61 9259 0800

FAX

+61 9877 6431

WEBPAGE

www.medmont.com

EMAIL

help@medmont.com

QSF-5083R6

Chisholm CM, Rauscher, FG, Crabb, DC et al. “Assessing visual fields for driving in patients with

paracentral scotomata”. Br J Ophthalmol. 2007, 1136; doi 10.

Wood JM, Dique T, and Troutbeck R. The effect of artificial visual impairment on functional visual

fields and driving performance. 1993, Clin. Vis. Sci ; 8: 563-575

Wood JM and Troutbeck R “Effect of restriction of the binocular visual field on driving

performance”. O p h t h. Physiol Optics. 1992(12): 291-298

Wood JM and Troutbeck R Effect of visual impairment on driving. Human Factors 1994; 36: 476-487

Wood JM and Troutbeck R Elderly drivers and simulated visual impairment. Opt. Vis. Sci 1995; 72:

115-124