Glaucoma New Zealand
- A Charitable Trust
Glaucoma New Zealand
Aims to
• eliminate blindness and visual disability from
glaucoma in our community
• inform and educate people about how best to
live with glaucoma
Glaucoma in General Practice
The aim of this initiative is to:
• Compare the presentation of glaucoma and
cataract in General Practice
• Address detection of glaucoma by optic disc
assessment.
• Review the “Risk Factors” for glaucoma
• Clarify the role of health and life-style issues
in patients with glaucoma.
A Common Clinical Encounter
This is a true patient scenario..
Visual loss from .....
A Christchurch CASE :
A 81 yr old man is referred by his GP for urgent
cataract surgery for his very poor vision.
He was having visual difficulties coping with
living alone and was concerned about his
driving.
He thought that charity or public hospital
cataract surgery would be the answer...
Past eye history
Five years earlier an eye specialist diagnosed
ocular hypertension and started timolol eye
drops. The patient completed the dispensed
medication then stopped treatment.
No follow up occurred.
The referring GP enclosed a copy of the reply
letter from the eye specialist when the patient
was seen five years earlier. It gave the above
detailed history.
Ocular examination in 2008...
The best corrected visual acuity was:
Right : 6 / 24
Left : 6 / 9
The intra-ocular pressure was:
Right : 40 mm Hg
Left : 40 mm Hg
The optic discs were both markedly cupped:
cup / disc ratios
Right 0.9+ Left 0.9
There was extensive visual field loss (see later)
There were early lens opacities present in both
eyes as is common in this age group
Humphrey visual fields in this patient
Left Visual Field
Right Visual Field
Humphrey Visual Fields
• The patients visual field is a “blackout” !
• There is minimal response centrally in the
left visual field. But none in the right field.
The mean deviation of loss is over 25
decibel in each eye.
• The blackout doesn’t mean he is totally
blind but that the highest intensity of light
for the machine has been reached. And he
still cannot see it
• Whatever, it is disastrous for the patient !
Implications for this man...
Primary open angle glaucoma is the main threat
to this man’s eyesight, his independence and
his driving licence.
Most of his sight loss cannot be restored.
Treatment of his ocular hypertension for five
years would have prevented this situation.
A further delay of a few months would have
been disastrous for him with intra-ocular
pressures at 40 mm Hg and with markedly
cupped optic discs.
Implications
A priority appointment should be given for this
patient, if the referral letter states :
• Visual acuity does not improve with a Pin Hole
• Raised intra-ocular pressure.
• Markedly cupped optic discs
• Visual field defects
• You suspect glaucoma
• None of these factors were noted.
Preventing treatable blindness is an order of
priority higher than restoring sight from
cataract, which can be done at anytime.
Outcome
This patient fortunately received an early
appointment because he went privately
despite limited means and no insurance.
Initial glaucoma treatment was commenced and
he had investigations and follow up in public.
He will not be able to return to driving. Which
means you and your loved ones may live
longer !
Comparison of
CATARACT and GLAUCOMA
Cataract and glaucoma compared
CATARACT
• The patient will present to you when the visual
disability reaches the threshold for that person
to complain about their vision.
• “Screening” for cataract is not required.
• Visual acuity with a pinhole is near normal for
early to modest cataract (and refractive errors)
• Vision can be restored by surgery at any stage
in the development of cataract from a clear
lens to one that has been dense for years.
Cataract and glaucoma compared
GLAUCOMA
• The patient will complain of visual problems
only at a late stage in glaucoma development.
• The sight lost cannot be restored (this century!)
• The cupped optic disc is at high risk for sudden
loss of vision from a retinal vein occlusion,
which adds insult to the injury !
• Early treatment is effective in preventing
progression in glaucoma damage.
(Level 1 evidence: multiple double blind trials)
Glaucoma in General Practice
THREE considerations for today:
• Detecting glaucoma : symptomatic and
asymptomatic patients.
• Assessment of “Glaucoma Risk Factors” :
determines appropriate monitoring and may
indicate pre-glaucoma intervention. (reviewed)
• Evaluation of health and life-style issues that
may accelerate damage to the cupped and
compromised optic disc in those with glaucoma.
Detecting Glaucoma
In Patients with symptoms
and
In Patients without symptoms
(everyone !)
In patients with symptoms:
Blurred vision, gradual visual loss, etc
• Do Pinhole VA. If No improvement be
concerned for serious eye pathology
(not cataract or refractive errors). But a good
PH VA does NOT exclude severe glaucoma.
• Assess risk factors for glaucoma. (see review)
• Assess the optic disc. (see below)
• Consider assessment of the visual field
(to be discussed in the next GNZ presentation)
In patients with symptoms:
Painful inflamed eye : consider angle closure
• Assess risk factors (see review)
Age, Asian, Hypermetropia, Family history
• Ask about halos around lights (corneal oedema)
• The pupil may be mid-dilated
(if small, the diagnosis is more likely to be iritis)
• The intra-ocular pressure will be very high and
must be measured.
• The optic disc will be normal except in chronic
angle closure when it will be cupped.
In people without symptoms :
Asymptomatic presentation occurs most often:
• Early to moderately severe glaucoma usually
presents without symptoms !
• Check Glaucoma out when the opportunity
arises.
• The “Routine General Check up”
Anyone requesting a “routine check up” is asking
“What will kill me, what will harm me, doctor ?”
Firstly cancer, secondly blindness, is the public’s
concern in many surveys.
That means glaucoma !
The first Glaucoma NZ Powerpoint presentation
for General Practitioners gave an overview of
glaucoma in your practice. It addressed “Risk
Factors”. See it on www.glaucoma.org.nz
This presentation mainly focuses on the optic
disc in glaucoma.
We acknowledge that the skill of ophthalmoscopy
cannot be taught here. But we note that new
types of ophthalmoscope are available to help
the non- specialist to view the optic disc.
Optic Disc Assessment
Ophthalmoscopy
• Direct viewing is most convenient for you.
Indirect viewing uses a slit lamp microscope.
• Documentation of the optic disc:
Draw the disc and its cup
Assess the vertical ratio of the cup diameter to
the disc diameter. Record as a decimal eg 0.3
Optic disc scanning : a technical assessment
GDx, OCT, HRT machines. They will become
widely used in the next few years.
Optic Disc Parameters to check
• Optic disc size and shape. Larger discs have
larger cups ! There is more room for the same
number (1.2 million) of nerve fibres.
• Optic shape is similar in both eyes in most
people. The exception is highly myopic eyes.
• Neuro-retinal rim: The ISNT rule is that it is
thickest Inferiorly, reducing Superiorly, Nasally
then Temporally in the normal disc.
• Disc margin haemorrhage (an important sign)
• Peripapillary atrophy
The Neuro-retinal rim / nerve fibres
GENERALISED LOSS
• Assess the cup / disc ratio esp. vertically.
• Assess the thickness of the rim to the cup.
• A normal cup is oval horizontally.
• The glaucomatous cup is often oval vertically.
• The mean c /d ratio is 0.3 with a wide range !
• Your index of suspicion will be enhanced if you see a
large c / d ratio. (As in the patient described.)
• Asymmetry in the c / d ratio between eyes is very
significant. (< 0.2 difference in 98 %)
The Neuro-retinal rim / nerve fibres
LOCALISED LOSS
• Look for localised notches in the rim.
• Focal loss is often inferiorly, then superiorly.
• Record as the c / d ratio in that meridian
eg. c/d 0.9 at 5 o’clock
PALE DISCS
• Glaucomatous discs may look pale as the cup
deepens and enlarges. BUT..
• True pallor of the rim ( the remaining nerve fibres) is
optic atrophy NOT glaucoma.
Typical cortical cataract shadows in the red reflex.
Expect good Pin hole acuity here or consider dual pathology
Fundus photo of the same eye. Blurred view from cataract but optic disc
visible : healthy disc with cup / disc ratio of 0.3
The optic disc in glaucoma
• Glaucoma is defined by progressive cupping
of the disc.
• A single observation of the discs may alter
your management of your patient.
• You will assess all risk factors that you can,
and determine an appropriate course of
action.
• You may seek a full eye examination where
otherwise no action may have been taken.
• You may write “suspicious of glaucoma” which
will generate a priority response !!
The optic disc in glaucoma
The following table outlines a range of optic disc
for comparison with your patient.
The image can be downloaded from the GP
Arena on www.glaucoma.org.nz
Your optic disc findings should be considered
along with the clinical presentation and your
assessment of the “Risk Factors” for glaucoma.
Asymptomatic patients with NO risk factors, refer:
OD c / d ratio of > 0.8
OD notch, haemorrhage, or asymmetry.
An evidence based guide does Not exist
“Optic Nerve Head Signs
in Glaucoma”, is kindly provided
by Dr Allan Simpson of
Christchurch.
The file is attached for you to
print and use for comparison
with the optic discs you see in
your patients !
The vertical cup to disc ratio is
an assessment of the diameter
of the cup as a ratio of the disc.
It is given as a decimal.
0.1 is a very small cup ; healthy !
1.0 means there is no neuro retinal
rim remaining. Its too late !
SUMMARY
• You are in the best position to prevent glaucoma
blindness in your patients.
• Glaucoma is progressive cupping of the optic
disc which you may be able to detect at least
when the cupping is severe.
• Patients may be harmed when visual blur is put
as cataract. A non urgent priority may be given..
• Glaucoma should be considered in other patient
presentations and especially when patients
request a “Routine general check up”
Please Promote Glaucoma Awareness
Glaucoma Risk Factors Reviewed
Risk Factors for Open Angle
Glaucoma
Identified without an eye examination
• Age
• Family history
• High myopia
• Previous eye trauma
• Steroid use
Risk Factors for Open Angle
Glaucoma
Identified by an eye examination
• Intra-ocular pressure
• Central corneal thickness
• Optic disc structure
• Intra-ocular pathology
Pseudo-exfoliation.
Pigment dispersion
Vascular and inflammatory disease
Congenital abnormalities
Risk Factors for Angle Closure
Glaucoma
• Age
• Family history
• Hypermetropia (long sightedness)
• Anterior chamber (AC) morphology
Shallow AC, narrow AC angles
• Race : Asian
The gold standard : “45 plus 5”
Glaucoma NZ recommends that every adult
have an eye examination at age 45 years and
every 5 years there-after.
Individuals with significant risk factors detected
by examination require more frequent
assessment.
By aged 80 yrs, many will need 2 yearly
examination.
The General Practitioner and
Glaucoma Awareness
Promote the “45 + 5” glaucoma eye test
Identify glaucoma risk factors
for greater attention
Incorporate Glaucoma Awareness and
screening recommendations into every day
practice.
Health and life-style issues
in the patient with glaucoma
Health and life-style issues in the
patient with glaucoma
Diabetes mellitus, hypertension and vascular
disease
• Primary glaucoma is not more frequent here.
• Routine Glaucoma Eye Examinations should
be done according to the standard
recommendation above, in these patients.
• However the cupped disc may be at risk if
there is high, low or fluctuating blood pressure.
• Treat these conditions gently !
• Stable good control is recommended.
Health and life-style issues in the
patient with glaucoma
Vascular spasm eg migraine, Raynaud’s
• Routine Glaucoma Eye Examinations should
be done according to the standard
recommendation above.
• Vascular spasm is implicated in glaucoma
progression in “Normal Tension Glaucoma”
where non-pressure factors appear to play a
significant role in cupping the optic disc.
• Stable good control is recommended.
Health and life-style issues in the
patient with glaucoma
Special life-style issues (theoretical)
• Short term IOP fluctuations maybe harmful :
Head down Yoga positions, Valsalva
manoeuvres e.g. playing wind instruments
• Situations with low pO2 :
e.g. prolonged high altitude, climbers, glider
pilots
Patients with marked glaucoma damage may
need to modify some life-style choices.
Glaucoma in your General Practice
A successful outcome of this initiative would be:
• You thinking “Glaucoma” when your patient
complains of blurred vision etc.
• You assessing the optic disc for marked cupping
by ophthalmoscopy in your patients to identify a
need for urgent referral.
• You appreciating the known risk factors or
markers, for developing glaucoma, that call for
greater attention than in the normal population.
• You considering the effect on optic disc perfusion
when managing your patient’s general health.
General Practice and Glaucoma NZ
Glaucoma New Zealand welcomes general
practitioner involvement in our mission to
“eliminate glaucoma blindness from our
community”.
Glaucoma NZ provides a “Professional Education
Package” on-line that presents ten glaucoma
cases with questions, answers and discussion.
You are welcome to register for it.
Glaucoma New Zealand welcomes your feedback
on this presentation.
Public education about glaucoma
Glaucoma New Zealand provides information to
the public who enrol with us. There is no fee.
We publish “Eyelights” a regular newsletter,
maintain a web site, and produce additional
educational materials.
See www.glaucoma.org.nz
Please encourage your patients with glaucoma to
enrol with us.
Glaucoma New Zealand wishes to
thank our sponsors
without whose help we could not
undertake our activities
General Practice and Glaucoma NZ
You can support our cause by:
• Donations
• Sponsorship
• Involvement in our activities in your area.
• Promoting bequests to Glaucoma
Glaucoma New Zealand thanks you for your
time and consideration with this presentation
Glaucoma New Zealand
Department of Ophthalmology
The University of Auckland
Private Bag 92019
Auckland
Tel 09 373 8779
Fax 09 373 7947
www.glaucoma.org.nz
Email: info@glaucoma.org.nz