1. The Canadian Association of Optometrists
Glaucoma
The Canadian Association of Optometrists

2. What is Glaucoma?
Glaucoma is an eye disease where the eye’s optic nerve is damaged
It is one of the leading causes of blindness in Canada

3. Eye Anatomy The optic nerve is a bundle of nerve fibers
It carries visual information from the retina to the brain

4. Fluid Circulation The eye has an internal fluid circulation system
Fluid is produced at the base of the iris

5. Fluid Circulation
The fluid flows through the pupil to the front of the iris

6. Fluid Circulation
The fluid exits the eye at the angle between the iris and the cornea where it drains through a spongy meshwork

7. Forms of Glaucoma There are several different forms of glaucoma
Primary Open Angle Glaucoma
Low Tension Glaucoma
Secondary Glaucoma
Angle Closure Glaucoma

8. Primary Open Angle Glaucoma (POAG)
POAG is the most common form of glaucoma
It occurs when the fluid drainage is poor and fluid builds up in the eye and the internal eye pressure goes up
This increased pressure can cause damage to the optic nerve and vision loss
The exact mechanism of damage is still unknown

9. Symptoms of Primary Open Angle Glaucoma
POAG develops gradually and painlessly and has no initial symptoms
Vision is normal in the early stages

10. Symptoms of Primary Open Angle Glaucoma
If untreated, peripheral or side vision is slowly lost
Tunnel vision

11. Symptoms of Primary Open Angle Glaucoma
Eventually, all vision may be lost

12. Risk Factors for Primary Open Angle Glaucoma
High Intraocular (Eye) Pressure
Over the age of 40
Family history of glaucoma
African or Caribbean descent
Thin cornea
High myopia (Nearsightedness)
Diabetes
High blood pressure

13. Ocular Hypertension
Some people can have high eye pressure but the optic nerve does not get damaged
This condition is called ocular hypertension
These patients must be closely followed because of the risk of developing glaucoma

14. Low Tension Glaucoma
Low Tension (or Normal Tension) Glaucoma is not as common
In these cases, the eye pressure is in the normal range but the optic nerve still gets damaged
The exact mechanism of damage is still unknown

15. Secondary Glaucoma
Glaucoma can develop as a complication from other conditions including:
Eye injuries
Uveitis (internal eye inflammation)
Pigment dispersion
Diabetes (Neovascular glaucoma)
Steroid use

16. Angle Closure Glaucoma
This type of glaucoma is an emergency situation
It occurs when the iris itself blocks the drainage angle and results in a sudden increase in pressure
Symptoms include severe eye pain, nausea, eye redness and very blurred vision
Immediate treatment is required

17. How is glaucoma detected?
Regular eye examinations by an optometrist or ophthalmologist are vital to detecting glaucoma
A number of tests are performed

18. Glaucoma Tests: Case History
A patient’s medical history, family history and background are important to determine the presence of risk factors

19. Glaucoma Tests: Visual Acuity
A refraction is done to determine best corrected vision
This shows central vision function

20. Glaucoma Tests: Slit Lamp & Gonioscopy
A special microscope called a slit lamp is used to examine the structures of the eye
A gonioscopy lens may be used to view the drainage angle

21. Glaucoma Tests: Tonometry
Eye pressure is measured with an instrument called a tonometer
Three types that are commonly used are:
Goldmann (Perkins)
Non-contact (air puff)
Tonopen

22. Glaucoma Tests: Ophthalmoscopy
Eye drops may be placed in the eyes to dilate the pupils
Special magnifying lenses are used to examine the retina and optic nerve for damage
Normal Optic Nerve
Suspicious Optic Nerve

23. Glaucoma Tests: Ophthalmoscopy
Advances are being made in digital imaging of the retina

24. Glaucoma Tests: Visual Field Test
Peripheral (side) vision is tested with a perimeter
The patient responds to flashes of light in different locations

25. Recent Developments
Recent studies have found that patients with thin corneas have a greater risk of developing glaucoma
Measurement of corneal thickness using an instrument called a pachymeter will become increasingly important

26. Recent Developments
New tools for measuring peripheral vision (visual field) have been developed such as the FDT

27. Recent Developments
Laser technology can now be used to image the retina and optic nerve and measure nerve fiber layer thickness

28. Recent Developments

29. Glaucoma Management
Optometrists and Ophthalmologists work closely together to treat glaucoma
Optometrists refer patients who are diagnosed with glaucoma to Ophthalmologists to start treatment

30. Glaucoma Management
Once treatment is started, monitoring duties are often shared. This includes regular pressure measurements and visual fields.
Ophthalmologists perform any surgical treatments if necessary

31. Glaucoma Treatment The goal is to decrease the eye pressure
The three main categories of treatment are:
Medication
Laser trabeculoplasty
Conventional surgery
Unfortunately, these treatments will not reverse any existing damage but they can slow the progression of the disease

32. Glaucoma Medications
Medications are usually the first type of treatment used
Eyedrops or pills are used to either decrease the fluid production or to increase the fluid drainage

33. Glaucoma Medications
There are several different types of medication available
The right choice will depend on what other medications are being taken, other medical conditions and the effectiveness in decreasing the eye pressure
Often, combinations of eyedrops are used

34. Laser Trabeculoplasty
This laser treatment helps to increase the fluid drainage
The surgeon uses a laser to burn the spongy meshwork that is located in the drainage angle

35. Conventional Surgery
With this treatment, the surgeon creates a new opening in the eye for the fluid to drain out from
If the new opening becomes plugged or narrowed, further surgery may be required

36. Coping with Vision Loss
Many patients with sight loss due to glaucoma can benefit from low vision aids
Optometrists can perform low vision assessments and prescribe magnifying devices to enhance both distance and reading vision

37. Coping with Vision Loss
These aids will not restore sight to normal levels but they allow people to maximize the amount of vision remaining

38. Early Detection and Treatment
Regular eye health examinations are important to detect glaucoma early so that treatment can be started and vision loss can be prevented

39. YOUR EYES deserve AN OPTOMETRIST!
The Canadian Association of Optometrists