Lecture 1. Epidemiology

Question 1

What is the definition of glaucoma?

Answer 1

Ocular tissue damage at least partially related to IOP

Question 2

What are the 2 major types of glaucoma? and which one is most common?

Answer 2

Open and closed angle. Open angle is most common

Question 3

Between primary and secondary angle closure, which defines a known cause and which defines an unknown cause?

Answer 3

Primary=unknown, secondary=known (glaucoma secondary to…)

Question 4

What do you call a pt who has elevated pressure, reduced visual fields and/or glaucomatous damage in their optic nerve but you have only seen them 1 time?

Answer 4

A “glaucoma suspect”. in order to diagnose a pt with glaucoma you must observe progression. Make sure to follow up with pt in 3 months.

Question 5

Name the 3 types of open angle glaucoma and their usual IOP

Answer 5

1) PAOG (primary open angle) greater than 21 w/ damage/vf loss.
2) OHT (ocular hypertension) gretaer than 21 w/o damage/vf loss.
3) NTG (normal tension glaucoma) less than 21 w/ damage/vf loss

Question 6

Name the 3 types of closed angle glaucoma

Answer 6

Primary and secondary closed angle glaucoma and congenital glaucoma.

Question 7

What is the prevalence of glaucoma in Caucasian populations over 40 yrs. old?

Answer 7

2%

Question 8

*Prevalence of POAG in African Americans/African Caribbeans is _____ times higher than in Caucasians?

Answer 8

4x (4x 2%=8%) **POAG affects African Americans the most

Question 9

(T/F) Angle closure is more prevalent in women

Answer 9

True

Question 10

(T/F) POAG is more common in women

Answer 10

False (no obvious correlation in increased incidence in men or women) only in closed angle glaucoma do we see a difference

Question 11

At what age for caucasians and African Americans do we find an increased risk of glaucoma?

Answer 11

Caucasians=40 yrs. old, African Americans=35 yrs. old, Hispanics=40 and are similar to Caucasians at first but then progress more rapidly than African Americans later on

Question 12

(T/F) according to the Beaver Dam study, 25% of POAG’s had IOPS of less than 21mmHG?

Answer 12

True (depending on what time of day, possible fluctuations)

Question 13

What is the prevalence of OHT in Caucasians?

Answer 13

3%

Question 14

(T/F) Caucasians are more likely to have POAG rather than closed angle?

Answer 14

True. Caucasians have wide angles and large anterior chambers. African Americans also have a lower prevalence of closed angle as well due to wide angles.

Question 15

(T/F) An elderly Chinese woman has the lowest risk of closed angle glaucoma?

Answer 15

False, chinese people and women have the highest risk and prevalence increases with age.

Question 16

*Japanese people are at the highest risk of which type of glaucoma?

Answer 16

NTG (normal tension)

Question 17

What is the prevalence of angle closure in the Japanese population?

Answer 17

0.31% very low

Question 18

*The Chinese population has a ____ times higher risk of developing angle closure glaucoma than POAG

Answer 18

3x Chinese are highest for risk of angle closure.

Question 19

*Would hyperopes have a higher tendency for closed or open angle glaucoma?

Answer 19

Closed

Question 20

IOP is a major risk factor for glaucoma. As IOP increases, how does your risk for glaucoma increase?

Answer 20

Pressures @ 26mmHg=30% chance of glaucoma, @27mmHg=70% chance of glaucoma, @30mmHg=80% chance of glaucoma. The risk greatly increases after 26mmHg.

Question 21

What are the 3 components of the glaucoma triad?

Answer 21

Optic nerve damage, visual field deficit, and elevated IOP.. This is “old thinking”, we know now that some forms of glaucoma, such as NTG, do not need high IOP’s to cause damage. There are also unknown factors of glaucoma.

Question 22

Most doctors treat pt’s when their pressures are above what?

Answer 22

Above 28mmHG, but some may treat at 26mmHg

Question 23

As IOP increases, the prevalence of glaucoma in African Americans _____ Caucasians

a) is less than
b) is the same as
c) is greater than

Answer 23

C. The prevalence of POAG at higher IOP increases exponentially (for African Americans) as IOP increases. For example @ 34mmHg, Caucasians have a prevalence of 7% and African Americans have a prevalence of 32% at the same IOP. Much lower pressures show similar prevalence rates between African Americans and Caucasians.

Question 24

What retinal cell is damaged in glaucoma? how many of them are we born with?

a) bipolar cells, 750,000
b) horizontal cells, 1.5 million
c) ganglion cells, 1 million
d) rods only, 15 million

Answer 24

c) Ganglion cells, 1 million. We lose approx 4,000 ganglion cells per year naturally.

Question 25

Data shows that myopes may have a higher prevalence of POAG, why is this?

Answer 25

This is a false association because myopes also happen to get more eye exams, increasing their frequency of being diagnosed.

Question 26

(T/F) According to the consensus guidelines, Diabetic pt's and pt's with diabetic eye disease are at risk for glaucoma and should be screened.

Answer 26

True. however the Baltimore eye study showed a protective effect and this could be due to increased blood flow in early diabetes. hard to say, but for boards, the answer is yes, they are correlated.

Question 27

* Your pt's blood pressure is 120/80, what is the mean pressure? a) 40 b) 60 c) 100 d) 200

Answer 27

C) 100

Question 28

*Ocular Profusion Pressure=____-____

Answer 28

OPP=BP-IOP

Question 29

``` As diastolic perfusion pressure increases, prevalence of POAG ______: A) increases B) decreases C) stays the same D) is completely eliminated ```

Answer 29

B) decreases. This is because of 2 main hypothesis of what cause glaucoma: 1) elevated BP 2) blood flow to the eye (if blood flow to the eye is not good--->higher risk of glaucoma)

Question 30

Genetic factors and glaucoma: Siblings=____ times risk Parents=____times risk Children=____times risk

Answer 30

Siblings=3.69x Parents=2.67x Children=1.12x

Question 31

(T/F) Hypertension in the short term (as it relates to risk of glaucoma) may be beneficial because higher pressure means more blood flow to the eye?

Answer 31

True. However chronic HTN narrows vessels over time leading to dramatic worsening in the long term. Low BP is also not good, organs can suffer.

Question 32

What percentage of pt's over 70 have glaucoma? a) 2% b) 3% c) 8% d) 12%

Answer 32

C) 8% (remember 2% over 40 yrs old have glaucoma)

Question 33

(T/F) smoking and alcohol consumption has an unknown correlation with glaucoma.

Answer 33

True. Some studies say yes, some say no, nothing conclusive

Question 34

What is the 3rd major cause of blindness in the USA? a) BB guns b) Diabetic Retinopathy c) Macular Degeneration d) Glaucoma

Answer 34

d) Glaucoma

Question 35

What is the zipcode effect? a) When you can determine the overall chances of glaucoma prevalence based on certain zip codes b) When you can recommend that your pt move to a different zip code and their glaucoma improves.

Answer 35

a) When you can determine the overall chances of glaucoma prevalence based on certain zip codes

Question 36

(T/F) the most common cause of blindness among African Americans is glaucoma

Answer 36

True. Rate of blindness in African Americans is 6-8 times more than in Caucasians.

Question 37

What is the cure for glaucoma?

Answer 37

There is no cure, only management. The doctor wants to start treatment early but not too early. Once treatment starts, you are on treatment for life