Refractive Error and Correction Options
Pharmacy Society Australia Presentation
The Vision Initiative
Professional Education Program
Outline
 Vision 2020 Australia
 The Vision Initiative
 Common causes of blindness and vision
impairment
 Refractive Error
 Correction of Refractive Error
 Pharmacy’s role in prevention of avoidable
blindness
 How to refer to vision services
Vision 2020 - The Vision Initiative
Save Your Sight
– Get Tested
 The key message of The Vision Initiative
 Funded by the Victorian Department of
Human Services
 Implemented by Vision 2020 Australia and
members such as Optometrists Association
Australia and RANZCO
 Victoria’s public health response to the
National Framework
The Vision Initiative
Victorian Partner Service Providers
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Able Australia
Blind Citizens Australia
Brotherhood of St Laurence
Centre for Eye Research
Australia
Diabetes Australia – Vic
Glaucoma Australia
Guide Dogs – Victoria
International Diabetes
Institute
Kerataconus Australia
Macular Vision Loss Support
Society of Australia
 Optometrists Association
Australia (Victorian Division)
 Orthoptic Association of
Australia
 Retina Australia – Vic
 The Royal Australian and
New Zealand College of
Ophthalmologists
 Royal Victorian Eye and Ear
Hospital
 Seeing Eye Dogs Australia
 St Vincent’s health
 Victorian College of
Optometry
 Vision Australia
Causes of vision impairment
80% vision impairment and blindness is
caused by five conditions:
 Under-corrected refractive error (62%)
 Cataract (14%)
 Age-related Macular Degeneration (AMD)
(10%)
 Glaucoma (3%)
 Diabetic eye disease (2%)
Structure and function of the eye
Structure and function of the eye
Retinal
blood
vessels
Macula
(fovea in
centre)
Optic nerve
Age-related Macular Degeneration
(AMD)
 Progressive condition affecting the central
area of the retina
 Age-related maculopathy (ARM) in the early
stages
 If disease progresses to AMD, irreversible loss
of central vision occurs, usually in both eyes
Advanced AMD
View with Age-related Macular
Degeneration
AMD Prevention
 Tobacco use
 Physical Activity
 Adequate intake of fruit and vegetables
- Dark leafy green vegetables
- Fish (Omega 3)
 Reduce saturated fat, use sparingly in
cooking
 American reports implicating margarine may
not be relevant to Australia
Diabetic Retinopathy
 Complication of longstanding diabetes
 25 times more vision loss than those without
 Elevated sugar levels damage the sensitive
blood vessels at the back of the eye
 90 % of those with diabetes will develop some
changes in their eyes
 Painless loss of vision due to leaky blood
vessels or scar tissue formation in the retina
Diabetic Retinopathy
Healthy retina
Broken blood
vessels
Cause scaring and
loss of vision
Diabetic Retinopathy Prevention
 Early detection and treatment essential
 Regular review and coordinated care
approach by GP and other eye care
practitioners
 Target levels for
 blood sugar levels < 7.0
 blood pressure < 130/80
 Cholesterol (LDL ideal) < 2.6 mmol/L
Cataract
 Progressive age related change
 Opacification of the internal lens of the eye
 Symptoms include
- Painless blurring and ‘dullness’ of vision
- Increased awareness of glare e.g. car lights
- Reduced contrast sensitivity
 Vision unable to be corrected with glasses
Mature Cataract
Glaucoma
 Topic of the second part of tonight’s
presentation
 50% suffers undetected! So…
Save Your Sight
– Get Tested
for the ‘sneak thief of sight’
Refraction is the passage of light through the
ocular media to focus an image onto the
retina
Under-corrected refractive error
- focus defect
 Long-sightedness (hyperopia)
 Light focuses behind the retina
 Trouble with near - effort (& possibly
distance vision)
 Short-sightedness (myopia)
 Light focuses in front of the retina
 Trouble with distance vision
 Astigmatism (oval shaped eye)
 Distance and/or near focus difficulty
 Presbyopia (age related near focus difficulty)
 >40 yrs should have eye test, incidence
increases with age
Types of Refractive Error
Long-sightedness (hyperopia)
 Near Vision blur, asthenopia &/or headache
with near vision tasks
 Print ‘runs together’
 Short concentration for near tasks
 Associated with esotropia (one eye turning in)
Types of Refractive Error
Short sightedness (myopia)
 Distance vision blur, squinting in distance, TV
and night Driving difficulties
 Poor concentration for board based learning
in school
 Headache and eyestrain less likely
Types of Refractive Error
Astigmatism (oval shaped eye)
 Can be of myopic or hyperopic or mixed type
causing dist &/or near problems
 Strong association of headache and eyestrain,
squinting of eyelids for dist &/or near
Types of Refractive Error
Presbyopia (age focus difficulty)
 Symptoms similar to hyperopia
except >40 YOA
 Holds near objects at arms length
 should have eye test as incidence
of most diseases increases with
age
Correction Options for Refractive Error
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Spectacles
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Contact Lenses
Refractive Surgery
 Corneal Onlays / Inlays
Spectacles
 Convenient, non-invasive, easily updated
 Protective – trauma & radiation Sunsmart –
slip, slop, slap
 Problematic in some environments – fogging,
perspiration, smudging
 Restrict peripheral vision, Bi/Multifocals zone
dependent
 Not ideal for physical activity – damage,
dislodgement
Ready-mades (“Magnifying Glasses”)
 Won’t ‘damage your eyes’ but asthenopia &
headaches possible
 Neglecting eyecare leads to vision loss
through non-detection or late detection
 Giving good advice with each sale
Save Your Sight
– Get Tested
Contact Lenses
 Less convenient than specs, mildly invasive,
easily updated if disposable
 Some splash protection, can be UV absorbing
 Problematic in dusty dirty environments,
allergies & atopy
 Danger of infection – pseudomonas
aeruginosa, acanthamoeba, fungal keratitis
 Good for sports
Contact Lens Problems
minor vs. medical emergency
Sign/Symptom
Less Serious
More Serious
Pain
bilateral
unilateral
CL removal
reduces
persists or 
Photophobia
Redness
mild
surface
conjunctival
none to mild
due to
lacrimation
severe in sunlight
deeper tissues ring
or sector around iris
profound > 2 lines
on letter chart
Vision loss
Refractive Surgery
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Radial Keratotomy (RK) ->
<- Photorefractive Keratectomy (PRK)
 Laser-Assisted In Situ
Keratomileusis (LASIK)->
<-Corneal Onlays / Inlays
Experimental
Presbyopic Inlay
Pharmacy’s Role in Prevention of
Avoidable Blindness
Engage clients on eyecare issues
Over 40?
Change in vision?
Family History of Eye Disease?
Diabetes?
Wearing / Buying Ready-mades?
Save Your Sight
– Get Tested
The Victorian Eyecare Service (VES)
 Provides low cost eye care and glasses to
holders of Pensioner Concession Cards (PCC)
and Health Care Cards (HCC)
 Funded by the Department of Human Services
 Staffed by qualified optometrists
 Glasses start from $33.00 a pair – get Tested!
 Consultations are bulk billed to Medicare
 Operates throughout Victoria
 Contact details:
- Corner of Cardigan and Keppel Street Carlton
- Telephone: 9349 7400
- www.optometry.unimelb.edu.au/clinicalservices/index.htm
Low vision service providers
 Low vision organisations and some
optometrists provide low vision services
 These services help people to adjust to vision
impairment by learning new ways to carry
out daily tasks
 They assist people in making the most of
their remaining vision
Referring to low vision service providers
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Able Australia
Telephone: 1300 ABLEOZ (1300 225 369)
Website: www.ableaustralia.org.au
Email: info@ableaustralia.org.au
Guide Dogs Victoria
www.guidedogs.asn.au
Ph: 9854 4467
Email: referrals@guidedogs.asn.au
Seeing Eye Dogs Australia
www.seda.org.au
Ph: 1800 037 773
Vision Australia
www.visionaustralia.org.au
Ph: 1300 VISION (1300 847 466)
Management of Glaucoma
•
An overview of Glaucoma
•
Practical aspects for Pharmacists
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Ophthalmologists’ management
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Ways Pharmacists can assist
Glaucoma
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Glaucoma can be considered a generic name
for a group of diseases causing optic
neuropathy and visual field loss, usually in
the presence of raised intraocular pressure.
Glaucoma is often asymptomatic until late
stages as the peripheral vision is often lost
first causing a “tunnel vision” effect
Glaucoma
It is estimated that visual impairment due to
glaucoma will double over the next two decades
Year
Age
60-69
70-79
80-89
>90
2004 2010 2014 2020 2024
1,191 1,487 1,853 2,083 2,225
3,069 3,259 3,653 4,793 5,616
8,669 10,268 10,924 12,387 14,176
813 1,081 1,229 1,359 1,489
Total VI
13,741 16,096 17,658 20,623 23,507
Total blind 8,561 9,890 11,289 12,595
Prevalence of visual impairment from Glaucoma
Source: Access Economics Pty Limited
From VIP, BMES and ABS population data
Glaucoma in Australia
Demographic distribution of glaucoma in
Australians over 40
10
9
8
7
6
Undiagnosed
Diagnosed
5
4
3
2
1
0
40-49
50-59
60-69
70-79
80-89
>90
Age
It is estimated only half of Australians currently
living with glaucoma have been diagnosed
Source: Taylor (2001)
Glaucoma risk factors
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Family history (4 times increased risk)
Age (increased risk after age 40)
Corneal thickness (thin)
High myopia
Diabetes
Race (African descent)
Hypertension
History of eye trauma
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Glaucoma Disease Prevention
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Often no “early signs” of disease
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All methods of current treatment rely on the
reduction of intraocular pressure
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No current medication has consistently
proven itself as neuro-protective or to
favourably influence optic nerve perfusion
Examinations for Glaucoma
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Tonometry
Ophthalmoscopy
Perimetry
Gonioscopy
Retinal nerve fibre
analysis
Normal
Abnormal
Examinations for Glaucoma
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Tonometry
• Brief and painless procedure where the
intraocular pressure is measured (normal range
is 10-21mmHg)
Diagnosing Glaucoma
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Ophthalmoscopy
• Allows for detailed
examination of the retina
and optic nerve head with
cup:disc ratio and vessels
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Gonioscopy
• A slit lamp and
gonioscopic mirror allows
evaluation of the anatomy
of the angle where the
cornea meets the iris
Visual field loss in Glaucoma
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The longer treatment is delayed the greater
the loss in vision
Visual field changes are imperceptible at
first and more rapid as time progresses
Visual field loss shows after 50% of nerve
firbres are damaged
Diagnosing Glaucoma
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Glaucoma vs. ocular hypertension
• OHT = IOP of up to 30mmHg with normal optic
discs and full visual fields
• IOP above 30mmHg has increased risk of central
retinal vein occlusion
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Need evidence of progression and structural
changes to confirm diagnosis
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HRT retinal nerve fibre layer analysis is
useful in closely monitoring these patients
Primary open-angle glaucoma
(POAG)
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Makes up more than 70%
of all glaucoma cases
Impairment of aqueous
drainage through the
trebecular meshwork
Results in excavation and
atrophy of the optic
nerve head
Visual field abnormalities
Other types of glaucoma
•
Angle closure glaucoma
• One of the few types that causes symptoms
• Severe pain, red eye, nausea or vomiting
• Extraordinarily high IOP, often 40-70mmHg
• Low tension glaucoma
• Rarer form of disease
where optic nerve
damage and vision loss
occur despite normal
intraocular pressure
PI in Angle closure glaucoma
Secondary Glaucomas
• Pigmentary
Pigment granules from the back of the iris
flake off and slowly block drainage channels
and increase IOP
• Traumatic
Blunt trauma to the eye tears ciliary body and
resulting in blood and other debris blocking
the drainage and increasing IOP
• Neovascular
Tissue which accompanies new blood vessels
growing near the trabecular meshwork blocks
drainage and increases IOP
Management of Glaucoma
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Topical medication for treatment of POAG
– Prostaglandin analogs
– Beta-blockers
– Alpha-agonists
– Carbonic anhydrase inhibitors
– Miotics
Glaucoma Medications
•
Beta blockers
Generic Name
Timolol maleate 0.5%
•
Drug Interactions
Adverse Reactions
Adrenaline, reserpine
Asthma, bradycardia,
depression, erectile
dysfuntion
Betaxolol HCl 0.25%,
0.5%
Beta Blockers,
Adrenaline
Levobunolol HCl
ophthalmic solution,
USP 0.25%, 0.5%
Oral Beta Blockers,
Adrenaline
Asthma, bradycardia,
depression, erectile
dysfuntion
Asthma, bradycardia,
depression, erectile
dysfuntion
Decrease production of intraocular fluid
Glaucoma Medications
•
Prostaglandin Analogs
Generic Name
Drug Interactions
Adverse Reactions
nil
Pro-inflammatory reaction
of HSV/HZO, eyelash
pigment changes, dry eye
Bimatoprost 0.03%
nil
Pro-inflammatory reaction
of HSV/HZO, eyelash
pigment changes, dry eye
Latanoprost 0.005%
Eye drops containing
thiomersal
Pro-inflammatory reaction
of HSV/HZO, eyelash
pigment changes, dry eye
Travaprost 0.004%
•
Increases drainage of intraocular fluid
Glaucoma Medications
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Alpha Agonist
Generic Name
Drug Interactions
Adverse Reactions
Brimonide tartrate
0.1%, 0.15%
MAOIs, CNS
depressants, alcohol
Oral dryness,
hyperaemia, irritation
Works to both decrease production of fluid and
increase drainage
Glaucoma Medications
•
•
Carbonic Anhydrase Inhibitors
Generic Name
Drug Interactions
Adverse Reactions
Brinzolamide
ophthalmic
suspension 1%
nil
Blurred vision, dry eye,
transient discomfort
Dorzolamide HCl 2%
(drops)
nil
Allergic reactions,
ocular irritation, bitter
taste
Acetazolamide
(oral)
Salicylates, folic acid
antagonists,
hypoglycaemics
Metabolic disturbances,
fatigue, kidney stones,
tingling, taste
disturbance
Decreases production of intraocular fluid
Glaucoma Medications
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•
Combined
Generic Name
Drug Interactions
Adverse Reactions
Dorzolomide HCl Timolol maleate
Beta Blockers, Ca
channel blockers
Ocular irritation,
taste perversion,
lacrimation
Lantanaprost Timolol maleate
Eye drops containing
theomersal, Beta
Blockers,
prostaglandins,
antidiabetic agents
Increased iris
pigmentation,
irritation, eyelash
changes
Combination of beta blocker and carbonic
anhydrase inhibitor
Practical aspects for
pharmacists
Compliance with eye drops is a frequent issue
Glaucoma patients’ medications are often
modified or increased if monotherapy fails
•
Techniques to maximise legibility of medication
labels for patients:
– Large print labels
– Large print medication lists
– Encourage to wear their spectacles
– Bold and black typeface not red
How Pharmacists can assist
• Liaison with GPs and eye healthcare providers
• Checking for drug interactions
• Eg. Topical + systemic Beta Blockers –
•
Alert Ophthalmologist if this occurs
Discussing instillation technique
• Emphasising importance of compliance
• Sitting/lying down to instill drops
• Having partner instill the drops for you
• Pressing on tear duct
• Waiting 5 minutes between using different drops
Laser treatments for Glaucoma
•
Selective Laser Trabeculoplasty (SLT)
and Argon Laser Trabeculoplasty (ALT)
Laser is applied in
evenly spaced spots
of the trabecular
meshwork
Laser burns cause shrinkage and contraction
of the collagen meshwork to create openings
and increase aqueous outflow
Laser treatments for Glaucoma
•
Selective laser trabeculoplasty (SLT)
uses a low-energy, large-spot, very
brief pulse to the trabecular meshwork
SLT
ALT
Laser treatments for Glaucoma
•
Perpheral Iridotomy
– Typically performed to treat
narrow angle or angle closure
glaucoma
– YAG laser is focused on the iris
root, creating an opening for
the aqueous fluid to move
through
– Usually holes are in superior
part of the iris which is covered
by the upper eyelid
• Less problems with glare
• No double vision from “new pupil”
Trabeculectomy
•
•
Mechanical formation of an
aqueous outflow channel
through the sclera and into
the subconjunctival space
Aqueous pools into the “bleb”
fluid sac and reduces IOP
OCT image of bleb
Save Your Sight week
An integrated campaign by The Vision
Initiative will promote the importance of
regular eye tests for people over 40
Activity includes television, radio and
newspaper advertising, media PR and a series
of public events from 11-16 March
Health Professionals- what can you do to
help?
Awareness of the campaign with increased
knowledge of common eye conditions, and
referral options
Support the campaign by accepting and
displaying promotional materials, posters,
post cards in your setting
Please tick box on registration sheet for us
to send you materials for display.
Vision 2020 Australia would like to thank John Clemens from the
Optometrists Association Australia and Dr. David McKnight from
the Royal Australian and New Zealand College of Ophthalmology
for this presentation
For more information please contact:
Robyn Wallace
Vision 2020 Australia
(03) 9656 2020
rwallace@vision2020australia.org.au
www.saveyoursight.org.au
www.vision2020australia.org.au
Vision 2020 Australia wishes to acknowledge the Victorian
Department of Human Services for funding The Vision Initiative