Glaucoma Flashcards
What produces aqueous humour
Non-pigmented epithelium of the pars plicats
What are the 3 main processes for the production of aqueous humour
- Diffusion
- Ultrafiltration
- Active secretion
What makes the aqueous humour optically clear
Ultrafiltration phase where the soluble substance is fenestrated across the ciliary capillary resulting in it becoming protein free
What affect does B2 have on aqueous humour
Increases aqueous secretion
What affect does a2 stimulation have on aqueous humour
Decreases aqueous secretion
What are the 2 routes of aqueous outflow
- trabecular outflow
- uveoscleral drainage
What is the conventional route of aqueous outflow
Aka trabecular outflow
- 90% of outflow
Through the trabeculum, through the canal of Schlemm and into episcleral veins
What is uveoscleral drainage
Across ciliary body into suprachoroidal space and is drained by venous circulation
What affect will increasing IOP have on outflow of aqueous humour
Increase outflow
What is the normal range of IOP
11-21 mmHg
How is IOP measure
To nome try
Neuroretinal rim thickness
ISNT
- inferior
- superior
- nasal
- temporal
What is a normal cup to disc ratio
0.3
What is disc cupping
When disc ratio is larger than 0.3
Risk factors of primary open angle glaucoma
- age
- fh
- African
- myopia
- diabetes
- raised IOP
- hypertension
Where is aqueous humour produced
Posterior chamber
What is another name for the anterior chamber angle
Iridocorneal angle
What time is IOP highest
In the morning
Is central corneal thickness higher in POAG
Yea
What endocrine disorder is associated with normal tension glaucoma
Thyroid disease
Risk factors for acute angle closure glaucoma
- age
- Asian
- female
- hyperopia
Symptoms of acute angle closure glaucoma
Painful red eye
Blurry vision
Halos
Headache
Vomiting
Pupil in acute angle closure glaucoma
Fixed mid dilated
Management of acute angle closure glaucoma
Acetazolamide - carbonic anhydrase inhibitor
Pilocarpine - miotic agent
Timolol
2nd line
Mannitol
Brimonidine
Definitive
Laser iridotomy - done for both eyes
What are the 3 classes of secondary open angle glaucoma
Pre-trabecular
Trabecular
Post trabecular
What type of glaucoma is pseudoexfoliative
Secondary open angle
What mutation is seen in pseudoexfolaition glaucoma
LOXL1
Features of pseudoexfoliation
Krukenberg spindles
Aqueous flare
What glaucoma is being described
Posterior layer of the iris rubs against the zonule as a result of excessive bowing of the mid-peripheral portion
Pigment dispersion syndrome
What is the pigment deposited like in pigment dispersion syndrome
Krukenberg spindles
What has the following features
Blurred vision on exertion
Pigment dispersion syndrome
What does neovascular glaucoma occur as a result of
Rubeosis iridis
What does retinal ischaemia cause the release of
VEGF
Interleukin 6
Causes of neovascular glaucoma
CRVO - most common
Diabetes
Retinal detachment
Can you use miotics in neovascular glaucoma
No
Cause of uveitic glaucoma
Fuchs uveitis
1st line for uveitic glaucoma
Beta blocker
What is posner-schlossman syndrome
Recurrent attacks of unilateral raised IOP{
Causes of posner schlossman syndrome
H pylori
CMV
HLA BW5
Phacolytic glaucoma
Occurs due to hyper mature cataract
When does red cell glaucoma occur
Acutely after hyphema and blunt trauma
When does ghost cell glaucoma occur
Few weeks after vitreous haemorrhage
What does iridocorneal endothelial syndrome include
Chandler
Cogan-reese
Iris atrophy
SECONDARY CLSOED ANGLE
SECONDARY CLOSED ANGLE
Phacomorphic glaucoma features
Same as primary closed angle but with cataract
What size of lens has a greater risk of dislocation
Small lens
What is an iris bombé seen in
Uveitic glaucoma
What gene is implicated for congenital glaucomas
CYP1B1
What is another gene that is implicated in congenital glaucomas
MYOC
What is the triad of primary congenital glaucoma
Photophobia
Epiphora
Blepharospasm
What tonometer is used in children
Perkins
What is average IOP in newborn
10-12
What is seen on slip lamp of congenital glaucoma
Haab striae
How do prostaglandins work
Increase uveoscleral aqueous outflow
Example of prostaglandin
Latanoprost
Side effect of prostaglandin
- hyperaemia
- eyelash thickening, lengthening
- iris hyperpigmentation
- increased risk of cystoid macular oedema
MoA of beta blocker
Decrease aqueous production
When should beta blockers not be applied
At bedtime as they exacerbate hypotension during sleep
MoA of a2 agonist
Decrease aqueous production and increase uveoscleral outflow
Example of a2 agonist
Apraclonidine
Side effect of brimonidine
Allergic conjunctivitis
MoA of carbonic anhydrase inhibitor
Inhibit aqueous secretion
When are carbonic anhydrase inhibitors contraindicated
Sulfonamdie alert
Example of carbonic anhydrase inhibitor
Brinzolamide
What is laser iridotomy mainly used for
Primary angle closure glaucoma
What laser is used for laser iridotomy
Nd:YAG laser
What is given to prevent bleb failure post trabeculotoym
5-fluorouracil
Mitomycin c
When is laser trabeculoplasty used
Open angle glaucomas
