Lecture 8 Angle closure glaucoma

Question 1

Which ethnic group is at the highest risk of angle closure glaucoma?

a) Caucasians
b) African Americans
c) Chinese
d) Japanese

Answer 1

c) Chinese (Japanese are at highest risk of NTG, African Americans are at highest risk for POAG)

Question 2

Which TWO of the following are at highest risk of angle closure glaucoma?

a) women
b) men
c) myopes
d) hyperopes

Answer 2

a) women (70% of cases are women)
d) hyperopes

(because they both tend to have eyes with shorter axial length)

Question 3

Which of the following is NOT a cause for secondary angle closure glaucoma?

a) neovascular signs
b) Marfan’s syndrome
c) uveitis
d) all of the above are causes

Answer 3

d) all of the above are causes

• Marfan’s syndrome is a connective tissue disorder which causes the forward displacement of the lens and iris, increasing risk of angle closure.
• In Uveitis, the cells and flare are present due to a breakdown in the blood aqueous barrier. Which can cause angle closure.
• Neovascularization can pull iris towards angle increasing risk of angle closure.

Question 4

Which of the following are causes for primary angle closure glaucoma?

a) neovascular signs
b) Marfan’s syndrome
c) uveitis
d) none of the above
e) all of the above

Answer 4

d) none of the above (primary means there is no known cause)

Question 5

Which one of the following is NOT a classification of angle closure closure glaucoma?

a) acute
b) subacute
c) chronic
d) subchronic

Answer 5

d) subchronic

Question 6

Which of the following is NOT a true statement regarding acute angle closure glaucoma?

a) A sign is red eye, which you wouldn’t see with POAG
b) A symptom is colored halos due to macular edema
c) IOP usually exceeds 40mmHg
d) Acute angle closure is painful
e) A possible sign is cells and flare

Answer 6

b) A symptom is colored halos due to macular edema. (This is false, they will see colored halos but it is due to corneal edema)

Question 7

Which of the following is NOT a (listed) sign of a prior attack of angle closure?

a) iris atrophy
b) scleral thinning
c) posterior synechiae
d) glaukomflecken
e) structural optic nerve damage

Answer 7

b) scleral thinning

Question 8

In acute angle closure, is the pupil reactive to light? why or why not?

Answer 8

No, it is not reactive to light. It is mid-dilated and vertically oval. The pupil does not react to light because the iris muscle doesn’t work. The pressure is so high, not good blood flow, ischemia kicks in, not allowing for the iris muscle to function.

Question 9

What is it called when the iris is connected to the peripheral cornea and trabecular meshwork?

a) iris synechiae
b) iris atrophy
c) plateau iris
d) ciliary congestion

Answer 9

a) iris synechiae (when angle closure is due to iris pushing forward into the anterior chamber, risk for anterior synechiae formation is high and almost certain with prolonged contact between the iris and peripheral cornea/TM. Once this happens, the angle will no longer open with an iridectomy and trabecular outflow will be permanently affected)

Question 10

Corneal edema is associated with angle closure. How does angle closure affect the cornea, causing edema?

Answer 10

With angle closure, pressures can reach upwards of 50mmHg or higher. Aqueous is forced into corneal stroma causing stretching of collagen lamellae and eventually epithelial edema.

Question 11

Red eyes (hyperemeia) is associated with angle closure. How does high IOP cause conjunctival vessel congestion?

Answer 11

Venous congestion occurs when IOP exceeds that of episcleral veins.

Question 12

Visible iris atrophy is associated with prior angle closure attacks. How does high IOP cause iris atrophy?

Answer 12

The abrupt increase in IOP interrupts the iris arterial supply resulting in ischemia (insufficient blood supply) causing damage to the iris in the form of stromal atrophy patches.

Question 13

Cells and flare are associated with angle closure. How are the 2 related?

Answer 13

Cells and flare is caused by a breakdown in the blood aqueous barrier. Cells and proteins can get trapped in the trabecular meshwork halting the outflow of aqueous.

Question 14

Which one of the following correctly describes Glaucomflecken?

a) changes in the corneal endothelium due to acute angle closure
b) changes in the crystalline lens due to acute angle closure
c) changes in the corneal stroma due to acute angle closure
d) changes in the trabecular meshwork due to acute angle closure

Answer 14

b) changes in the crystalline lens due to acute angle closure (anterior lens opacities, literally means glaucoma flecks)

Question 15

Which one of the following is NOT a sign of post congestive angle closure?

a) elongated ciliary processes
b) folds in descemets membrane
c) posterior synechiae
d) stromal iris atrophy with spiral like configuration

Answer 15

a) elongated ciliary processes (i just made that up, don’t worry, its not a sign of anything mentioned)
* note: You should do gonio on every pt once a year, otherwise you could miss these things.

Question 16

Which TWO signs are autonomically stimulated signs of acute angle closure?

a) nausea and vomiting
b) slow heart rate (bradycardia) and profuse sweating (oculocardiac reflex)
c) increased appetite
d) increased heart rate (tachycardia)

Answer 16

a) nausea and vomiting

b) slow heart rate (bradycardia) and profuse sweating (oculocardiac reflex)

Question 17

What is the main difference between acute and subacute angle closure?

Answer 17

subacute angle closure has similar symptoms/signs as acute angle closure, however, can come and go (intermittent), be less intense, and spontaneously disappear.

Question 18

Which one of the following does NOT apply to chronic angle closure?

a) evidence of peripheral anterior synechiae (PAS)
b) patient is highly symptomatic
c) similar to POAG with cupping and visual field loss
d) easily missed unless routine gonio is performed

Answer 18

b) patient is highly symptomatic (this is false, pt is asymptomatic until vision loss)

Question 19

What is pupillary block and how does it cause angle closure?

Answer 19

Pupillary block is an increased resistance to flow of aqueous humor through the pupil from the posterior chamber to the anterior chamber, leading to anterior bowing of the peripheral iris over the trabecular meshwork and to angle-closure glaucoma.

Question 20

(T/F) Eyes with a thicker and anteriorly positioned lens tend to have shallower anterior chambers.

Answer 20

true (this would be an anatomical mechanism of angle closure)

Question 21

(T/F) Eyes with plateau iris have an increased risk of angle closure, therefore, be sure to check the IOP after dilation.

Answer 21

true. Iris plane is flat but drops abruptly in the far periphery making a narrow recess over the trabecular meshwork. Anterior chamber appears to be normal but the angle looks narrow due to the shape of the peripheral iris.

Question 22

Which one of the following is NOT a mechanism that increases iridotrabecular contact with iris plateau syndrome?

a) thicker iris
b) more posterior insertion of the iris
c) more posterior position of the ciliary body
d) both “b” and “c” are incorrect

Answer 22

d) both “b” and “c” are incorrect. Anterior iris insertion and anterior position of the ciliary body both increase iridotrabecular contact.

Question 23

How do you treat pupillary block?

Answer 23

peripheral iridotomy

Question 24

How do you treat plateau iris syndrome?

Answer 24

peripheral iridotomy wont work because of anterior positioning of ciliary body. angles are still narrow. Indentation gonio can confirm plateau iris because it causes the iris to assume a concave shape however you will notice the peripheral iris remains elevated due to anterior positioning on ciliary process. Treatment for these cases should be argon or diode laser iridoplasty.

Question 25

(T/F) when it comes to angle closure treatments, the order of procedures are as follows: try medical treatment first. If medications do not work, try laser treatments. If laser does not work, try surgical treatments.

Answer 25

true

Question 26

Which one of the following is a surgical (non laser) treatment used in angle closure cases?

a) iridotomy
b) iridectomy
c) iridoplasty
d) iridostomy

Answer 26

b) iridectomy. (iridotomy and iridoplasty are laser treatments, iridostomy was a made up term)

Question 27

(T/F) Intravenous medications, such as acetazolamide and mannitol, work well to treat angle closure. However, most states do not allow OD’s to initiate this form of treatment.

Answer 27

true (IV mannitol is an osmotic drug. It needs to be warmed up before administering because it forms crystals at room temperature. It also requires the use of a filter to prevent crystals from entering the blood stream.

Question 28

What is the medical treatment protocol for an OD who has a pt with angle closure?

a) argon laser iridotomy
b) argon laser iridoplasty
c) iridectomy
d) the ABC procedure

Answer 28

d) the ABC procedure (“a” and “b” are LASER treatments and usually not done by OD’s and “c” is a SURGICAL procedure)

Question 29

Describe the ABC procedure for acute angle closure treatment.

Answer 29

1) Alpha-2 agonist (Brimonidine)
2) Beta blocker (timolol-caution in asthmatics, or betaxolol)
3) Carbonic anhydrase inhibitors (dorzolamide-caution sulfa allergies)

• if pt has sulfa allergies you will just skip the carbonic anhydrase portion.
• Give one drop of A, wait 5 minutes. Give one drop of B, wait 5 minutes. Give 1 drop of C, wait 5 minutes. Repeat 3 times
• Since OD’s cannot give IV CAI’s, like IV acetazolamide, we will give them the oral form of acetazolamide. (caution sulfa allergy, dont give to pts with sulfa allergy). Two tablets of 250mg (not 1 tablet of 500 because that strength is slow release). They may be nauseous, if they vomit the meds, DONT give them more.
• Check IOP after 1 hour. If lower than 40mmHg, add Pilocarpine every 15 minutes for 45 minutes and repeat. If higher than 40 mmHg, do ABC’s again.

Question 30

After performing the ABC procedure on your pt with angle closure, you will want to refer them to an ophthalmologist. Sometimes the ophthalmologist will not be able to see them until the next day. You will want to give the pt which 4 take home medications?

Answer 30

1) Prednisolone acetate 1% (every 1 to 6 hours-approx every 3 hours)
2) Acetazolamide 500mg sequel (slow release) BID
3) Alpha agonist or beta blocker BID
4) Pilocarpine 2% QID

Question 31

Match the following procedures with the following indications:

1) iridotomy
2) iridoplasty

a) plateau iris
b) occludable angle

Answer 31

1) iridotomy performed for b) occludable angle

2) iridoplasty performed for a) plateau iris