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Visual System
The following case studies relate to injuries to the Visual System.
More detailed information regarding the assessment of injuries to the visual system
may be found at Chapter 8 of the MAA’s Permanent Impairment Guidelines and
Chapter 8 of the AMA4 Guidelines.
The Motor Accidents Authority of NSW makes no warranties or representation about
the accuracy or completeness of the information contained in these Case Studies. It
should be noted that the information contained herein is not provided as a substitute
for legal advice.
VISUAL
Case Study #
V1
V2
V3
V4
Brief Description
Peripheral retinal atrophy
Convergence insufficiency
Traumatic optic neuropathy
Apportionment of visual impairment
Primary Body System
Visual
Visual
Visual
Visual
Secondary Body System
Injuries: Vitreous Floaters
Right Visual Field Loss
The claimant was involved in a head-on collision and sustained, amongst other
injuries, a head injury with facial bruising and blurred vision. Following recovery from
surgery for other injuries sustained in the motor vehicle accident (MVA), she noticed
her vision was blurred in both eyes. The blurred vision resolved within three months
of the MVA; however, she noticed ‘black spots’ and a ‘cobweb like structure floating’
in her right eye.
The claimant had no past history of eye disease or accidents. She had never worn
glasses. There was no family history of eye disease.
She can read and see well in the distance in both eyes. She reports no ‘flashes’ of
light and considers her vision is substantially the same as prior to the accident. She
does complain, however, of problems with glare and occasional headaches. She has
some irritation in the right eye and uses eye drops with only partial relief.
The claimant had been reviewed by an Ophthalmologist and prescribed some drops
to help with the feeling of irritation in the right eye.
Clinical Examination
• Distance vision (uncorrected) right eye: 6/6 (normal).
•
Distance vision (uncorrected) left eye: 6/6 (normal).
•
Reading vision (uncorrected) left eye: J1 (normal).
•
Ocular movements were normal and the eyes were straight for distance and
near vision, however, there was an exophoria for near vision. (Exophoria is a
condition in which the alignment of the eye is straight when both eyes are
open, but either eye drifts outward when covered).
•
Pupillary reactions, lids, anterior segments, lenses, corneal sensation, ocular
media, measurement of proptosis and ocular tensions were normal in each
eye.
•
Fundi were normal.
•
There were two small spots of peripheral retinal atrophy.
•
Cup disc ratio was 0.3 in each eye.
•
Computerised Humphrey Visual Fields revealed a small area of decreased
sensitivity in the peripheral superior right field.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
The claimant’s presentation was consistent with her reported symptoms, including
right vitreous floaters and right visual field loss. The condition was considered stable.
Impairment Evaluation
The claimant’s presentation was consistent with her reported symptoms, including
right vitreous floaters and right visual field loss.
Visual Acuity
• Near and distance for both eyes = 0% loss of central vision (calculated using
AMA4, Table 2 p.211).
Combined loss of central vision both eyes = 0% loss (AMA4, Table 3, p.212).
Visual Field Loss –
Left Eye
• Loss of central vision = 0%. Loss of visual field = 0%.
Visual System Impairment (left eye) = 0% (AMA 4, Combined Values Table, p.322).
Right Eye
• Loss of central vision = 0%.
•
Direct up-gaze is 25° of field.
Normal is 45°, thus there is a loss of 20° (AMA4, Table 4, p.212).
•
Visual field retained in the right eye is 480° (500-20). This equals 50% loss of
the left visual field (AMA4, Table 5, p.214).
•
Visual System Impairment for right eye = 4% (AMA4, Combined Values Table,
p.322)
•
There is no additional impairment for any diplopia.
Whole Person Impairment
Right Eye Visual System Impairment (4) and Left Eye Visual System Impairment (0)
using Table 7, page 219 (AMA4) equals = 1%.
Conversion of 1% Visual System Impairment to Whole Person Impairment = 1% WPI
(AMA4, Table 6, page 218).
The total assessed Whole Person Impairment due to the ocular injuries is 1%.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
This matter was subject to review by a Medical Review Panel. These are the Review
Panel’s findings.
Claimant’s Date of Birth: 7 March 1974
Date of Motor Accident: 20 February 2006
Injuries: Convergence insufficiency – right eye blurred vision
Clinical Findings
Visual acuity was 6/6 in both eyes. On examination of her muscle movements she
has marked convergence insufficiency. On examination of her fundi under a mydriatic
I could find no abnormality. Intraocular appear to be within normal limits. The only
abnormal clinical finding was the convergence insufficiency which measured 28cm
on the RAAF rule.
Panel Decision
The panel considered the assessment of the visual system using Chapter 8 of the
AMA Guides (4th Edition). The panel concluded that no assessment of impairment
could be made for either visual acuity (Tables 2 & 3), visual fields (Tables 4 & 5) or
ocular movements (diplopia).
The panel then considered the last paragraph in column 1 on page 8/209 of AMA 4.
This paragraph states:
If an ocular or adnexal disturbance or deformity interferes with visual function
and is not reflected in diminished visual acuity, decreased visual fields, or ocular
motility with diplopia, the significance of the disturbance or deformity should be
evaluated by the examining physician. In that situation, the physician may
combine an additional 5% to 10% impairment with the impaired visual function of
the involved eye.
The panel noted that Assessor had used this paragraph and had chosen to combine
10% impairment.
The panel noted though that the additional 10% impairment was to be combined with
the impairment of the involved eye. It was not an additional 10% whole person
impairment. From Table 7 on page 8/219 of AMA 4 10% impairment of the right eye
and 0% impairment of the left eye gives a 3% visual system impairment for both
eyes. Utilising Table 6 on page 8/218 a 3% visual system impairment converts to a
3% whole person impairment.
The panel concluded that the correct assessment for the claimant’s blurred vision in
the right eye is 3% WPI.
The whole person permanent impairment of the injuries caused by the accident was
calculated as follows:
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
Body Part or
System
Visual system
(right eye)
AMA Guides/
MAA
Guidelines
References
(chapter/
page/table)
Stabilised
(YES/NO)
Current
%WPI*
%WPI* from
pre-existing
OR
subsequent
causes
%WPI* due to
motor
accident
Chapter 8,
Tables 6 &
7, pages 218
& 219
Yes
3
0
3
%WPI = percentage whole person impairment
Determination Regarding the Degree of Whole Person Impairment of the
Injured Person as a Result of the Injuries Caused by the Motor Accident
The total percentage whole person permanent impairment for assessed injuries
caused by the motor accident is 3%. Therefore the total whole person impairment is
not greater than 10%.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
Injuries: Traumatic Optic Neuropathy
The claimant a motorbike rider struck by a car. He suffered skull and facial fractures.
Approximately one month prior to the accident, the claimant had obtained
prescription glasses for reading for the first time. He had no previous history of eye
trauma, disease, operations or head trauma. There was no family history of eye
problems.
Since the accident, the claimant has complained that his eyes have felt ‘different’. He
went to his optometrist after the accident and had new glasses prescribed and this
improved his vision. He wears the glasses for both near and distant vision. If he does
not wear his glasses his eyes feel sore and vision becomes blurred. He can drive at
night, work with a computer and watch TV without reported difficulty.
Since the accident, the claimant has had to change the prescription of his glasses
several times.
Clinical Examination
• Distance vision (uncorrected) right eye: 6/6 (normal).
•
Distance vision (uncorrected) left eye: 6/6 (normal).
•
Reading vision (uncorrected) right eye: J1 (normal).
•
Reading vision (uncorrected) left eye: J1 (normal).
•
Small refractive error in each eye (astigmatism).
•
Ocular movements revealed no diplopia.
•
Convergence, accommodation, pupillary, ocular tensions, anterior segments,
ocular media, lids fundi and crystalline lens were all normal.
•
Computerised visual fields 30-2 test revealed that in the right eye there were a
few slight decreases in sensitivity in the periphery. In the left eye there was
definite peripheral visual field loss in the nasal segment.
Impairment Evaluation
The claimant suffered from a left traumatic optic neuropathy due to the motorbike
accident consistent with recorded head injury and skull fractures.
Ocular Movement
• Ocular movements were normal
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
Visual Acuity
• Near and distance for both eyes = 0% loss of central vision (AMA4, Table 2
p.211).
• Combined loss of central vision both eyes = 0% loss (AMA4, Table 3, p.212)
Visual Field Loss - Left eye
• Loss of central vision = 0%.
• Visual field retained in the left eye = 250 degrees (calculated using AMA4,
Table 4, p.212). This equals 50% loss of the left visual field (AMA4, Table 5,
p.214).
• Visual Impairment for left eye = 50% (AMA4, Combined Values Table, p.322)
Right eye
• Loss of central vision = 0%
• Loss of visual field = 0%
• Visual Impairment for right eye = 0% (AMA4, Combined Values Table, p.322).
Whole Person Impairment
Right Eye Visual System Impairment (50) and Left Eye Visual System Impairment (0)
using Table 7, p.219 (AMA4) equals = 13%.
Conversion of 13% Visual Impairment to Whole Person Impairment = 12% WPI (AMA
4, Table 6, p.218).
The total assessed Whole Person Impairment due to the ocular injuries is 12%.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
This matter was subject to review by a Medical Review Panel. These are the Review
Panel’s findings.
Injuries: Full thickness laceration of the left cornea
Previous viral infection - almost total loss of sight in the right eye
Clinical Findings
Clinical examination revealed some intolerance to glare. Reading glasses are agerelated and not related to the injury.
The right eye has no useful vision because of previous corneal infection. The left
vision is 6/6 (normal) with glasses which contain a small astigmatism correction.
Previous eye records are unavailable but the claimant states he had normal vision
prior to the accident. Distance vision without glasses is 6/6 (say 6/7.5) (20/25). Near
vision was a normal J1 (14/14) without the astigmatism correction.
Panel Decision
The Panel referred to Chapter 8 of the AMA4 Guides and in particular the method of
assessment set out on page 209. The Panel agreed on an assessment of 10% visual
impairment of the left eye, due to significant glare intolerance. They further agreed
that the visual impairment of the right eye was 100%, and that using the visual
system combination tables in the AMA4 (Table7 page 220) to combine the 100%
impairment of the right eye with the 10% impairment of the left eye gives a total
visual system impairment of 33%, which converts to a total whole person impairment
(WPI) of 31% (Table 6, page 218 AMA4). The current WPI was therefore agreed to
be 31%.
The Panel further agreed that the pre-existing impairment was 100% of the vision of
the right eye and no impairment of the left eye. Again using the visual system
combination tables in AMA4 (Table 7, page 220) to combine the 100% impairment of
the right eye with the 0% impairment of the left eye gives a total visual system
impairment of 25%, which converts to a total WPI of 24% (Table 6, page 218 AMA4).
The pre-existing WPI was therefore agreed to be 24%.
The Panel also agreed that the applicable methodology, as outlined in both the
AMA4 and MAA Impairment Guides, is to deduct the pre-existing WPI from the
current WPI, thus 31% minus 24%, which gives 7% WPI caused by the subject
accident.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.
Body Part or
System
Visual system
(left eye)
AMA Guides/
MAA
Guidelines
References
(chapter/
page/table)
Stabilised
(YES/NO)
Current
%WPI*
%WPI* from
pre-existing
OR
subsequent
causes
%WPI* due to
motor
accident
Chapter 8,
Tables 6 &
7, pages 218
& 219
Yes
31
24
7
%WPI = percentage whole person impairment
Determination Regarding the Degree of Whole Person Impairment of the
Injured Person as a Result of the Injuries Caused by the Motor Accident
The total percentage whole person permanent impairment for assessed injuries
caused by the motor accident is 7%. Therefore the total whole person impairment is
not greater than 10%.
Any queries in respect of the methodology used in assessing permanent impairment may be directed
to the WPI e-mail enquiry service at [email protected]. This service is operated by the
Injury Management Branch of the MAA who are responsible for the content and publication of the
MAA Permanent Impairment Guidelines.