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MEETINGS FOR 2016-2017
Colour Vision Assessment and the Use
of Colour in Clinical Practice


Wednesday 11 October 2017
14.00 hrs
City University
London, EC1V 0HB


Programme:

Part 1: Colour vision assessment
14.00 hrs Introduction
14.05 hrs Kathryn Albany-Ward
14.20 hrs John Barbur
14.45 hrs Marisa Rodriguez-Carmona
15.10 hrs Roopa Vermala
15.30 hrs Granville Halstead Tea
Part 2: The use of colour in clinical practice
16.00 hrs Catherine Suttle
16.20 hrs Arnold Wilkins
16.40 hrs John Lawrenson/Chris Hull
17.05 hrs Discussion
17.20 hrs Finish


Venue:
Room ELG01, Drysdale Building, City University (entrance in Northampton Square)

Time:
14.00 hrs until 17.20 hrs

Admission:
Open to all, free


Abstracts:

Part 1: Colour vision assessment

Colour Vision Screening in Schools – Kathryn Albany-Ward
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A presentation introducing the work of Colour Blind Awareness, the main body of which will consider the implications of the current colour vision screening environment following removal of school screening from the Healthy Child Screening Programme in 2009. Diagnosis is now dependent upon parents and optometrists. We will look how many children are actually being diagnosed and move on to consider, in practical terms, the effects upon their education. The conclusions will cover how optometric practice can improve the current situation.

Colour assessment, isolation of colour signals – John Barbur

The problems associated with the most common methods for assessing colour vision will be reviewed and data that describe variability in normal trichromats and in subjects with congenital deficiency will be presented.  The use of age specific limits of normal trichromatic colour vision will be discussed in relation to detection of acquired loss of chromatic sensitivity. 
Finally, results of extensive, clinical studies designed to detect the earliest changes in colour vision in diabetes will also be presented.

When, how and why to assess colour vision in practice – Marisa Rodriguez-Carmona

Colour vision assessment has gained significance as a result of increased knowledge of colour vision changes in acquired and congenital deficiencies. Since early 19th Century colour assessment was mainly of interest within occupations. Nowadays, colour plays a greater role in daily lives and has become even more important in visually-demanding, occupational environments. This talk will describe why minimum colour vision requirements have been introduced within occupations, how colour vision is assessed using occupational colour screening tests and the statistical outcomes of such tests.

Detection of early loss of color vision in age-related macular degeneration (AMD) – with emphasis on drusen and reticular pseudodrusen – Roopa Vemala

The aim of our study was to assess and grade the loss of chromatic sensitivity in patients with Age-related Macular Degeneration (AMD) and to investigate whether the severity of color vision loss can be used to discriminate various stages of AMD. Chromatic sensitivity was measured using the Color Assessment and Diagnosis (CAD) test in asymptomatic individuals with early/intermediate AMD and compared to normative data. Every eye (n=90) with intermediate AMD had chromatic sensitivity loss in either RG/YB or both (p<0.0001) compared to age-matched normal subjects. Both chromatic mechanisms were affected, but in general, eyes with reticular pseudodrusen and eyes with central macular thickness (CMT)< 200 µm had significantly higher CAD thresholds. In conclusion, although cone photoreceptors may remain relatively unaffected in early and intermediate stages of AMD, the processing of cone signals in the retina can, however, be heavily disrupted with subsequent loss of both YB and RG chromatic sensitivity.

Part 2: The use of colour in clinical practice

Coloured overlays and precision tinted lenses – is colour choice repeatable? – Catherine Suttle

Visual stress consists of perceived distortions or discomfort while reading. It is claimed that these symptoms are alleviated by viewing through coloured lenses or overlays, with a specific colour required for each individual. Here, we describe a study in which we test whether the same colour is repeatedly beneficial in 21 adults and children with visual stress. Our findings suggest that people with visual stress are unlikely to find exactly the same colour to be optimal on different occasions, and raise questions about the need for precise colour specification in tinted lenses for visual stress.

On the reliability of colorimetry - Arnold Wilkins

We describe two studies in which patients underwent assessments with the Intuitive Colorimeter. In both studies assessments were undertaken on two occasions. The studies differ in respect of the colorimeters used, the methods employed, the interval between examinations, and the masking of patients and examiners. Nevertheless both studies show similar reliability of the assessments. This reliability is as expected from previous literature. We explore the implications of these findings for the precision necessary when prescribing coloured filters.

Blue light filters and their use in ophthalmic practice – John Lawrenson/Chris Hull

Blue-blocking (BB) spectacle lenses, which attenuate short-wavelength light, are being marketed to alleviate eyestrain and discomfort when using digital devices, improve sleep quality and potentially confer protection from retinal phototoxicity. We conducted a systematic review to investigate the relative benefits and potential harms of these lenses. We included randomised controlled trials (RCTs) which investigated the effect of BB spectacle lenses on visual performance, symptoms of eyestrain or eye fatigue, changes to macular integrity and subjective sleep quality. We found a lack of high quality evidence to support using BB spectacle lenses for the general population to improve visual performance or sleep quality, alleviate eye fatigue or conserve macular health.


DATE 21 Sept 2017