Glaucoma Flashcards
Is a condition where pressure inside the eye rises to the point of causing damage to the optic nerve with associated loss of vision
Glaucoma
It usually affects both eyes, and it is the leading cause of blindness in the world.
Glaucoma
Normal IOP
10-21mmHg
Two accepted theories how increased IOP damages the optic nerve in Glaucoma
- The Direct Mechanical Theory
- The Indirect Mechanical Theory
Suggests high IOP damages the retinal layer as it passes through the optic nerve head
Direct Mechanical Theory
Suggests that high IOP compresses the microcirculation in the optic nerve head, resulting in cell injury and death
Indirect Mechanical Theory
Stages of Glaucoma
- Initiating events
- Structural alterations in the aqueous outflow system
- Functional alterations
- Optic nerve damage
- Visual loss
Stages of Glaucoma
Precipitating factors include
o Illness, Emotional stress
o Congenital narrow angles, long-term of corticosteroids
o Mydriatics medications causing pupillary dilation
Initiating Events
Stages in Glaucoma
Stages of Glaucoma
Tissue and cellular changes caused by factors that affect aqueous humor dynamics lead structural alterations
Structural Alterations in the Aqueous Outflow System
Stages of Glaucoma
Conditions such as increased IOP or impaired blood flow create functional changes that lead to the fourth stage
Functional Alterations
Stages of Glaucoma
Atrophy of the optic nerve is characterized by loss of nerve fiber and blood supply and this fourth stage inevitably progresses to the fifth stage
Optic Nerve Damage
Stages of Glaucoma
Progressive loss of vision is characterized by visual field defects
Visual Loss
Clinical manifestations of Glaucoma
Silent Thief of Sight
Blurred vision
Eye pain
Red eye
Dilated pupils
Severe pain in the head
Diagnostic Procedures: Glaucoma
- Tonometry
- Ophthalmoscopy
- Perimetry
- Gonioscopy
The doctor first numbs eye and then he takes this tool and places it on eye
This tool measures the eye pressure
Tonometry
Doctor puts eye drops into the eye, which dilates the pupils and then he can look into your eye and see your optic nerve
Ophthalmoscopy
A visual field test that helps patients with glaucoma and tests if there is lost vision
Perimetry
Doctor numbs eye, then uses a special contrast lenses that magnify inside the eye
Gonioscopy
Types of Glaucoma
- Open Angle Glaucoma
- Closure Glaucoma (acute or narrow angle)
- Pigmentary
- Secondary Glaucoma
- Congenital Glaucoma
Most common type and comprises about 90% of all cases of glaucoma
No symptoms for this glaucoma
Chamber is open and appears normal
Open Angle Glaucoma
The angle of the canal is blocked by a part of the iris
This kind can only be treated with laser surgery to take it away almost completely but is not all the way gone
Closure Glaucoma (acute or narrow angle)
Occurs when pigment from the iris flakes off and blocks the drainage canal
Pigmentary
Can develop only from specific things like tumor, diabetes, and a medical condition most likely having something to do with your eyes
Secondary Glaucoma
