Lecture 8 - Angle Closure Glaucoma Flashcards
Which race has the highest prevalance in regards to Angle closure glaucoma?
Chinese asians
What are the major risk factors associated with angle closure glaucoma, other than race?
- Women (70% cases) 2. Older age 3. Hyperopes (small axial length) 4. First degree relatives of an angle closure pt.
Primary angle closure consists of ____ degrees or less of the TM being visible.
180 degrees or less
True or False. IOP and the Disc are normal in Primary Angle closure.
True
What are the three types of clinical presentation of angle closure?
- Acute angle closure glaucoma 2. Subacute angle closure glaucoma 3. Chronic angle closure glaucoma
List 5 symptoms of Acute Angle closure glaucoma.
Ocular pain Nausea and vomiting Blurred vision, Colored halos around lights Loss of vision
What are the 4 ocular signs of acute angle closure glaucoma
1.Conjunctival and ciliary congestion, 2.Corneal edema 3.Shallow peripheral anterior chamber with cells and flare 4.Intraocular pressure usually exceeds 40 mmHg
4 signs of prior attack of angle closure
- iris atrophy, 2. Posterior synechiae, 3. glaukomflecken 4. structural optic nerve damage- cupping or pale nerve
5 signs of acute congestive angle closure glaucoma
- Severe corneal edema 2. Dilated, unreactive vertically oval pupil 3. Ciliary Injection 4. Shallow anterior chamber 5. Complete angle closure (shaffer grade 0)
What two structures of the eye does the Iris come into contact when a Synechiae is present?
- Peripheral cornea 2. Trabecular Meshwork
True or False. Synechiae will form when the iris is on the angle for a long period of time and it will form within the first few hours of an acute attack.
False. All is correct other than the synchaie formation, as it will take a longer period of time. Note: Once this occurs, the angle will no longer open with an iridectomy and trabecular outflow will be permanently affected
At 50 mmHg, What will occur to the cornea?
Corneal edema and halos will form
Aqueous that is forced into the corneal stroma will cause stretching of ______ ________ and _________ ________
Collagen lamellae and Epithelial edema
What will happen to the pupillary sphincter when IOP is increased?
Paralysis and Ischemia Note: This will cause a MID DILATED pupil
When venous congestion occurs, what other pressure must it exceed?
Episcleral veins
What are the tell-tale signs of Ciliary and conjunctival vessel congestion?
Iris blood vessels = dilated Conjunctival veins = painful red eye
How does Iris stromal atrophy occur?
The abrupt increase in intraocular pressure causes an interruption of the arterial supply to the iris, resulting in ischemia which causes damage to the iris, leaving behind patches of stromal atrophy
You notice protein in the anterior chamber, what has occurred?
Aqueous flare = break down of blood aqueous barrier
Signs of postcongestive angle-closure
1.Folds in Descemet membrane 2. Stromal iris atrophy with spiral-like configuration 3. PAS 4. Fine pigment on iris 5. Fixed dilated pupil 6. Glaukomflecken
What two autonomic stimulation reaction will occur when a acute angle closure attack has occurred?
Nausea and vomiting Note: Bradycardia (slow heart rate) and there is often profuse sweating
What is the major difference in sub acute angle closure vs. acute angle closure glaucoma?
Sub acute Angle closure = intermittent, low intensity and may spontaneously disappear
List 3 variables that occur during chronic angle closure glaucoma?
- Peripheral anterior synechiae (PAS) 2. Increased intraocular pressure 3. Patient asymptomatic until vision loss
What are 3 signs of chronic angle closure glaucoma
- Similar to POAG with cupping and field loss 2. Easily missed unless routine gonioscopy performed 3. Variable amount of angle closure
What is pupillary block?
Facilitating a pressure differential between the anterior and posterior chambers that causes forward bowing of the relaxed, peripheral iris
True or False. Aging increases lens thickness
True
What is a plateau iris?
Everything looks normal except the angle looks narrow or closed due to the shape of the peripheral iris
What are the 3 mechanisms that increase iridotrabecular contact?
- Thicker iris 2. Anterior iris insertion 3. Anterior position of the CB
What is the plateau iris caution?
Eyes with plateau iris configuration may have angle-closure when the pupil is dilated -iridotrabecular apposition
What is the treatment for a plateau iris with relative pupillary block?
Peripheral iridotomy
What is a treatment for Plateau Iris syndrome?
Argon or Diode Laser iridoplasty
What are the 4 goals when using medical treaments for ACG?
- Lower IOP 2. Alleviate Pain 3. Clear cornea 4. Prevent synchiae
What is the best treatment for ACG?
Intravenous medications 1. Acetazolanmide - 500mg IV 2. Mannitol - IV
What is the treatment protocol in order?
- Alpha -2 agonist- Brimonidine 2.Beta blocker- Timolol (caution in asthmatics ) or Betaxolol 3. Carbonic anhydrase inhibitor – Dorzolamide (Caution sulpha allergy contraindication) Note: Each medication is given every 15 minutes
How often should IOP be checked after administering drugs?
Every 1 hour
How often should you add pilocarpine when lowering IOP?
Every 15 minutes for 45 minutes
What is the prescription you would give your pt to take home with?
- Prednisolone acetate 1% q1-6 hours (approx every 3 hours) 2. Acetazolamide 500 mg sequel BID 3. Alpha agonist or beta blocker BID 4. Pilocarpine 2% QID
What are the details of preforming a laser procedure?
