The visual system

AMA4 Chapter 8 (p 209) applies to the assessment of permanent impairment of the visual system, subject to the modifications set out below. Before undertaking an impairment assessment, users of the Guidelines must be familiar with:

• the Introduction in the Guidelines
• chapters 1 and 2 of AMA5
• the appropriate chapter(s) of the Guidelines for the body system they are assessing
• the appropriate chapter(s) of AMA4 for the body system they are assessing.

The Guidelines take precedence over AMA4 and AMA5.

Introduction and approach to assessment

10.1 The visual system must be assessed by an ophthalmologist.

10.2 AMA4 Chapter 8 (pp 209–22) is adopted for the Guidelines, without significant change.

10.3  AMA4 is used rather than AMA5 for the assessment of permanent impairment of the visual system because:

• the equipment recommended for use in AMA5 is expensive and not owned by most privately practising ophthalmologists (eg the Goldman apparatus for measuring visual fields)
• the assessments recommended in AMA5 are considered too complex, raising a risk that resulting assessments may be of a lower standard than if the AMA4 method is used
• there is little emphasis on diplopia in AMA5, yet this is a relatively frequent problem
• many ophthalmologists are familiar with the Royal Australian College of Ophthalmologists’ impairment guide, which is similar to AMA4.

10.4 Impairment of vision should be measured with the injured worker wearing their prescribed corrective spectacles and/or contact lenses, if that was normal for the injured worker before the workplace injury. If, as a result of the workplace injury, the injured worker has been prescribed corrective spectacles and/or contact lenses for the first time, or different spectacles and/or contact lenses than those prescribed before injury, the difference should be accounted for in the assessment of permanent impairment.

10.5 The ophthalmologist should perform, or review, all tests necessary for the assessment of permanent impairment rather than relying on tests, or interpretations of tests, done by the orthoptist or optometrist.

10.6 An ophthalmologist should assess visual field impairment in all cases.

10.7 In AMA4 Section 8.5 ‘Other conditions’ (p 222), the reference to ‘additional 10% impairment’ means 10% WPI, not 10% impairment of the visual system.