test for macular pigment

METROVISION - 4 rue des Platanes 59840 PERENCHIES FRANCE

Tel: +33 3 20 17 19 50 Fax: +33 3 20 17 19 51

[email protected] http://www.metrovision.com

Version 05/01/2015 2015 Metrovision

USERS MANUAL

3 / 30 Copyright 2015 Metrovision

TABLE OF CONTENTS

INTRODUCTION ........................................................................................................................................................... 5

EXAMINATION BASICS................................................................................................................................................. 7

MACULAR PIGMENT AND AGE RELATED MACULAR DEGENERATION ............................................................................ 8

MACULAR PIGMENTS AND NUTRITION .......................................................................................................................... 8

MACULAR PIGMENTS AND NUTRITION .................................................................................. ERREUR ! SIGNET NON DEFINI.

REALIZATION OF EXAMS ........................................................................................................................................... 11

PATIENT'S INSTALLATION ............................................................................................................................................. 12

QUALITY CONTROL ....................................................................................................................................................... 14

EXPLOITATION OF RESULTS ....................................................................................................................................... 15

ACCESS TO RESULTS ...................................................................................................................................................... 16

MACULAR PIGMENTS ANALYSIS ................................................................................................................................... 16

OTHER ANALYSIS ........................................................................................................................................................... 16

PATIENT'S INFORMATION ............................................................................................................................................. 19

STORING THE RESULTS ................................................................................................................................................. 19

PRINTING THE RESULTS ................................................................................................................................................ 19

TECHNICAL SPECIFICATIONS ...................................................................................................................................... 21

CLINICAL EXAMPLES .................................................................................................................................................. 23

NORMAL VALUES ...................................................................................................................................................... 25

INFLUENCE OF DIET ....................................................................................................................................................... 26

INFLUENCE OF AGE ....................................................................................................................................................... 26

EDITION OF PROCEDURES ......................................................................................................................................... 27

BIBLIOGRAPHY .......................................................................................................................................................... 29


Macular pigments


Introduction

INTRODUCTION

This document describes the use of the Test for macular pigment density application available on the Vision Monitor

system.

Before reading this document, you should be familiarized with the general information related to the

hardware and software of the Vision Monitor.

These information are available in the following documents:

DOCUMENT CONTENU

The Vision Monitor Introduction and general operation

General functions of the Vision Monitor software

Recommendations for the installation of Vision Monitor Systems

Recommendations for the installation of equipment

Installation of MonPack3 system Installation of MonCv3 system

Installation and safety of the equipment


Macular pigments


Examination basics

EXAMINATION BASICS


Macular pigments

MACULAR PIGMENT AND AGE RELATED MACULAR DEGENERATION

The fovea region of the retina has a yellow color due

to the high concentration of a non-bleachable pigment

called the macular pigment.

This pigment has a filtration effect of blue light. On

average it absorbs 60 percent of the blue light, but

inter-individual variations are very large.

(WALD, 1945)

It has been shown that the pigment density is

maximum at the fovea and that it decreases sharply

with eccentricity to reach a rather constant value at

about 4 degrees.

(SNODDERLY & al, 1984)

Photographs of a cross section of the central retina in

primate retina under green (top) and blue (bottom)

illumination. Dark areas correspond to absorption of

light by pigment.

(SNODDERLY & al, 1984)

The macular pigment is believed to reduce the effect

of glare and to minimize chromatic aberration, so

improving visual acuity and contrast sensitivity.

(WHITEHEAD & al, 2006)

In relation with age related macular degeneration, the

blue light filtering effect may play a protective role

against oxidative retinal damage.

(WHITEHEAD & al, 2006)

It has been shown that dietary modification can

change the macular pigment density.

(HAMMOND & al, 1997)

MACULAR PIGMENTS AND NUTRITION

It has been shown that a change in alimentary diet or

the use of nutritional supplements may change the

density of macular pigments.

(HAMMOND & al, 1997, DESMETTRE, LECERF& SOUIED,

2004)

MEASUREMENT OF THE MACULAR PIGMENT DENSITY

Several psychophysical techniques have been

proposed to estimate the spatial distribution of

macular pigment optical density.

They have a common basic principle which is to

compare the sensitivity of the patient to blue light to

his/her sensitivity to another wavelength such as red

light which is not absorbed by the pigment.

One technique is the hetero chromatic flicker

technique (STABELL & STABELL, 1980) which is

frequently used in recent research studies.

It consists in alternating rapidly two lights of different

colors (blue and red for example). This alternation is

perceived as a flicker. The luminance

of one of the two sources is then


Examination basics

adjusted to obtain a minimum perception of flicker,

which corresponds to an equal luminance of the two

sources.

Another technique is using differential thresholds

(WILLIAMS & al, 1981) which consists in comparing

differential thresholds obtained with blue and red light.

It is similar to the classic visual field test except for

the use of chromatic stimuli.

The hetero chromatic flicker technique allows faster

measurements but appears to be very difficult for

patients with little experience.

The differential threshold technique is found to be

more reliable for clinical applications and for this

reason has been selected on the Vision Monitor.


Macular pigments


Realization of exams

REALIZATION OF EXAMS


Macular pigments

PATIENT'S INSTALLATION

First step:

Click on to access to the identification of the patient and examined eye.

Enter the birth date to allow the program to determine the age of the patient. This data is very important because it is used to adjust the starting value of the tests and to compute the normal values of thresholds.

If the birth date is not entered, the program will assume that the patient is 20 years old.

Second step:

Click on the icon which corresponds to the selected examination protocol.

Adjust the height of the seat and of the electric table (if available) to achieve the best possible comfort for the patient.

Place an occluder over the non-tested eye.

Place the optical correction for near vision (1 ft). The optimal refractive correction takes into account the correction for distance vision (sphere and cylinder) with an addition depending on the age of the patient:

Age (years) Addition to the far vision

correction

< 30 0

30-39 +0.50

40-44 +1.00

45-49 +1.50

50-55 +2.25

> 55 +3.00

The correction used for the exam can be computed

automatically by clicking on button during the

identification of the patient.

Enter the sphere and cylinder for distance vision and

the program automatically fills the Correction with

the value to be used during the exam.

Notes:

(1) The correction for astigmatism is taken into

account by adding half the value of the cylinder

correction to the spherical correction.

(2) When the pupils are dilated with a mydriatic agent

that paralyses the accommodation, refractive

correction does no longer depend on age. In that case,

select the option dilated pupils.

(3) The correction value given by the program

corresponds to the nearest correction available in the

set of large field lenses provided by Metrovision.

However, it is possible to obtain the exact spherical

correction putting in the configuration file the

following lines:

[REFRACTION]

metrovision=false


Realization of exams

Adjust the vertical position of the chin rest with

command button 1 so that the examined eye is at the

level of the eye marks 2.

On the video control, the tested eye should be within

the rectangular control area.

First step: measurement of the foveolar threshold for

red and blue

The visual stimulator displays a circle, in the middle of

which blue and red stimulus will be presented.

Explain the patient that he/she will have to press the

button every time a stimulus will be presented.

Click on the button to start the

presentation of stimuli..

Second step: measurement of peripheral thresholds

for red and blue

The visual stimulator displays a central fixation dot.

The patient must fixate the central dot and use the

press button every time a point appears in the

periphery.

If the fixation dot is not clearly visible, press on button

to increase its size.

Click on the button to start the

presentation of stimuli.

Automatic fixation control

If the device is equipped with the option automatic

fixation control, initialize it by clicking on button

.

If its not equipped with this option, the fixation

control is made by presentation of tests inside the

blind spot.

The program measures the direction of the glance that

will be used as reference to detect the patients

fixation errors. A message superposed on the eye

image will appear to indicate the initialization results.

If the initialization is successful the

patients responses will be invalidated


Macular pigments

in case of fixation errors. If it fails, repeat the

command or click on button that will

detect eye movements in the process of the exam.

You can also measure the pupil by clicking on button

on the right side of the video control window.

Duration between the presentation of

tests

This duration is displayed on button .

It can be modified in the process of the exam by

clicking on this button if the rhythm of the test

presentation is too quick for the patient.

QUALITY CONTROL

The information bar down the exam window enables a

quick evaluation of the exam in process. The items are

green when the results are of good quality and red in

case of problem.

The number of validated measures regard to the

number of measures programmed enables to

evaluate the progress of the exam.

The quality of the patients fixation is indicated by

the number of fixation losses (here 1) compared to

the number of control tests (here /19).

The patients attention is periodically controlled

with the presentation of fake tests which are not

seen.

The responses to these fake tests are counted as

attention losses (here 2) compared to the number

of control tests (here /22).

If the patients response times are abnormally fast,

it will also be posted as attention losses.


Exploitation of results

EXPLOITATION OF RESULTS


Macular pigments

ACCESS TO RESULTS

Results are accessible directly at the end of each examination or can be accessed from the hard disk when they have

been recorded.

MACULAR PIGMENTS ANALYSIS

Result from a subject with a normal optical density of

macular pigments

For each result, the graph above shows the absolute

threshold values versus the eccentricity measured

with red tests (red curve) and blue tests (blue curve).

Each curve is obtained from the foveolar threshold,

the average of measured thresholds at 2 degrees of

eccentricity and the average of measured thresholds

at 10 degrees of eccentricity.

The graph on the right shows the relative thresholds,

that is to say the threshold difference between fovea

and periphery (at 10 degrees of eccentricity).

It enables to eliminate the eventual influence of

absorption of the blue by the crystalline lens which is

supposed to be identical for central and peripheral

measures.

This graph shows up the attenuation of blue

thresholds by the macular pigment.

The estimated value for the optical density of macular

pigments is displayed under the graph.

The deficit corresponds to the difference between the

result obtained on the patient and the average of a

reference group of subjects with a recommended diet

(refer to chapter on normal values).

A positive deficit shows that the pigments optical

density is lower than this average. The value of the

deficit is followed by the statistical value of the result

when compared to a group a subjects with a

recommended diet.

Result from a subject with an abnormally low macular

pigment optical density

OTHER ANALYSIS

Several analyses can be performed:

the visual field analysis

the follow-up analysis

the comparison with the image of the eye fundus

Easy way: the different analysis can also be selected

directly from the results' menu.



Visual field analysis

This analysis allows visualizing the threshold of the

tested points.

The results are displayed in blue for blue tests and in

red for red tests.

Follow-up analysis

This analysis allows the evaluation of the evolution of

the patient over several consecutive exams.

The program automatically searches on the hard disk

all the exams performed with the same patient's name,

with the same tested eye and the same birth date.

The program displays the list of exams in chronological

order.

Evolution of indices

This graph represents the evolution in time of each of

the indices:

sensitivity at the fovea for blue and red stimuli

sensitivity in the periphery for blue and red stimuli

macular score

Superposition of the visual field and eye

fundus

This analysis allows the superposition of visual field

map on the image of the patient's eye fundus.

The superposition method is that proposed by Pr BEK

(BEK T. Accurate superimposition of visual field data

onto fundus photographs, Acta Ophthalmol.

1990,68,11-18).

When the analysis is started, a new window entitled

"SUPERIMPOSE IMAGE OF EYE FUNDUS" is displayed

with a map of the values of measured points.

Note: this map is reversed "upside down" with

respect to the visual field map so that it can be

superimposed over the image of the eye fundus.

The next step is to acquire the digital image of the

eye fundus.

One click on button opens a menu

allowing you to select the image file from the results

database.


Macular pigments

Note: use the button in the control bar of the

Vision Monitor program to import a photograph in

the results database.

The photograph can be imported either through a

computer network or from a storage media such as a

USB key, a CDROM, etc

The program is compatible with the major image file

formats: JPEG, BMP, etc.

The image of the eye fundus should then appear in the

superposition window.

The next step is to define the position of the fovea and

the papilla that are used as references for a precise

superposition of the visual field map.

In order to better identify these features, the red

component of the image can be eliminated by clicking

on button .

Click on button and then click on

the corresponding point of the image.

Perform the same operation with button

and the corresponding point of the

image.

The program automatically adjusts the image and

displays the result of the superposition:

An additional click on button allows

the restoration of the red component of the image.

Corrections:

- The position of the eye fundus image can be finely adjusted with the arrow keys of the keyboard "up", "down", "right" and "left".

- The magnification of the eye fundus image can be finely adjusted by pressing simultaneously the "SHIFT" key and the arrow keys of the keyboard "up", "down", "right" and "left".

- The image can also be rotated by pressing the keys "page up" and "page down".

Axis:

Axis and parallels (every 5 degrees of eccentricity) can

be added with a simple click on button

.



Printing the results, exporting the results to other

applications

To print the final result, click on .

To save the result image click on button

, or on to make a copy in the

clipboard

PATIENT'S INFORMATION

This command gives access to the patient's

information. It can be useful for adding comments

before recording or printing the result

STORING THE RESULTS

Click on button to store the results

on the hard disk.

The reference number of the record appears on top of

the screen.

The crossed sign on the button indicates that the

result has been stored.

PRINTING THE RESULTS

The print command allows printing the visual field

result and the different analysis.

The crossed sign on the button indicates that the

result has been printed.

Easy way: you can also print the results and the

different analysis directly from the results' menu.


Macular pigments


Technical specifications

TECHNICAL SPECIFICATIONS

The tests are presented over a white background with a luminance of 10 cd/m2.

The size of the chromatic tests is equivalent to Goldmann size III.

The reference luminance (0 dB) corresponds to 65 cd/m2 for the red tests and 27 cd/m2 for the blue tests.


Macular pigments


Clinical examples

CLINICAL EXAMPLES


Macular pigments

Subject with a normal optical density of macular pigments.

Patient with an abnormally low macular pigments density and a diet poor in lutein and zeaxanthin


Normal values

NORMAL VALUES


Macular pigments

INFLUENCE OF DIET

Source: CROCHET & al. Evaluation of macular pigment

optical density with a color perimetry technique.

Normal values and influence of diet. ARVO 2009.

Method:

Exams were performed on 54 subjects with normal

visual acuity, normal eye fundus and no ophthalmic

disease.

Subjects were interviewed about their dietary habits

by a questionnaire written for this study according to a

list of foods established by Pasteur Institute in Lille (Pr

Lecerf) and classified into two groups:

One with a recommended diet consisting of

more than 5 fruits and vegetables rich in

Lutein and Zeaxanthin and fat fish, omega 3

and no smoking habit.

Another group with the subjects who did not

match these criteria.

Results: The average value of the macular pigment

optical density (MPOD) in the tested population was

3.49 db (0.349 log units) with a standard deviation of

2.0 dB.

The figure hereby shows the distribution of the results

from the two groups. The group with a

recommended diet has a significantly higher MPOD

(average value = 5.06 dB, standard deviation = 1.9 dB)

than the group with a poor diet (average value =

2.30 dB, standard deviation = 1.5 dB).

The difference between the 2 populations is highly

significant (p < 0.0001).

MPOD (dB)

Recommended Non recommended

diet diet

INFLUENCE OF AGE

Foveolar thresholds for blue and red chromatic tests

as a function of age

Between 20 and 60 years of age, the sensitivity

thresholds decrease with age by 5 dB for the red

stimuli and by 7 dB for the blue stimuli. The dispersion

of the results also increases with age.

Blue and red test thresholds in the peri foveolar area

Between 20 and 60 years of age, the sensitivity

thresholds decrease with age by 4.5 dB for the red

stimuli and by 6 dB for the blue stimuli. The dispersion

of the results also increases with age.


Edition of procedures

EDITION OF PROCEDURES

Not available at the moment.


Macular pigments


Bibliography

BIBLIOGRAPHY


Macular pigments

CROCHET M., ZANLONGHI X., CHARLIER J. Evaluation of macular pigment optical density with a color perimetry technique. Normal values and influence of diet. Poster, ARVO 2009.

DESMETTRE T., LECERF J.M., SOUIED E.H. Nutrition et dgnrescence maculaire lie lge J. Fr. Ophtalmol., 2004, 27, 9: 3S38-3S56.

HADDAD W.M., SOUIED E., COSCAS G., SOUBRANE G. Pigment maculaire et dgnrescence maculaire lies lge. Implications cliniques. Bull. Soc Belge Ophtalmol. 2006, 301, 15-22.

HAMMOND B.R., JOHNSON E.J., RUSSEL R.M. & al Dietary Modification of Human Macular Pigment Density Invest Ophthalmol. Vis Sc. 1997, 38:1795-1801.

ROUGIER M.B., DELYFER M.N., KOROBELNIK J.F. Le pigment maculaire et sa mesure in vivo. J Fr. Ophtalmol., 2008; 31, 4, 445-453.

SNODDERLY D.M., AURAN J.D., DELORI F.C. The Macular Pigment. II. Spatial Distribution in Primate Retinas. Invest. Ophthalmol. Vis Sc. 1984, 25, 674-685.

STABELL U, STABELL B: Variation in density of macular pigmentation and in short-wave cone sensitivity with eccentricity. J Opt Soc Am 70:706, 1980.

WALD G. Human vision and the spectrum. Science. 1945,101, 653-658.

WHITEHEAD A.J., MARES J.A., DANIS R.P. Macular Pigment A Review of Current Knowledge. Archives Ophthalmology. 2006, 124, 1038-1045.

WILLIAMS DR, MACLEOD DIA, and HAYHOE MM: Punctate sensitivity of the blue-sensitive mechanism. Vision Res. 21:1357, 1981.

TABLE OF CONTENTSINTRODUCTIONEXAMINATION BASICSMACULAR PIGMENT AND AGE RELATED MACULAR DEGENERATIONMACULAR PIGMENTS AND NUTRITIONMEASUREMENT OF THE MACULAR PIGMENT DENSITY

REALIZATION OF EXAMSPATIENT'S INSTALLATIONn Automatic fixation controln Duration between the presentation of tests

QUALITY CONTROL

EXPLOITATION OF RESULTSACCESS TO RESULTSMacular pigments analysisOTHER ANALYSISn Visual field analysisn Follow-up analysisn Superposition of the visual field and eye fundus

PATIENT'S INFORMATIONSTORING THE RESULTSPRINTING THE RESULTS

TECHNICAL SPECIFICATIONSCLINICAL EXAMPLESNORMAL VALUESINFLUENCE OF DIETINFLUENCE OF AGE

EDITION OF PROCEDURESBIBLIOGRAPHY

test for macular pigment

Documents

macular pigments analysis

exploitation of results

metrovision users manual

patients installation

patients information

perenchies france tel

examination basics

influence o