Glaucoma

Question 1

Perfusion pressure

Answer 1

Difference between arterial and venous pressure
Mean ocular perfusion pressure = mean BP – IOP
Blood vessel resistance also determines blood flow
Autoregulatory mechanism is present in retinal vessels to maintain blood flow regardless of perfusion pressure

However this mechanism fails in glaucoma

Question 2

Optic nerve head in myopia

Answer 2

Vertical –oval shape
Thinning of temporal neural rim
Prominent peripapillary halo

Question 3

Nitric oxide

Answer 3

Beneficial at certain concentration as a vasodilator.
Neurotoxic in higher concentration
Inhibits mitochondrial function and disrupts DNA

Question 4

CAIs contraindications

Answer 4

• Sulfa allergies
• Diabetic patients susceptible to ketoacidosis
• Patients who have hepatic insufficiency and cannot tolerate the increase in serum ammonia
• Patients with chronic obstructive pulmonary disease, in whom increased retention of carbon dioxide can cause potentially fatal narcosis from a combination of both renal and respiratory acidosis

Question 5

CAIs systemic side effects

Answer 5

These include numbness, paresthesias, malaise, anorexia, nausea, flatulence, diarrhea, depression, decreased libido, poor tolerance of carbonated beverages, myopia, hirsutism, increased serum urate, and, rarely, thrombocytopenia and idiosyncratic aplastic anemia

Question 6

Normal blind spot

Answer 6

located 15 degree temporal and 7.5 degree in diameter

5 degrees wide by 7 degrees tall

Question 7

If any threshold is seen greater than 40 in central is probably

Answer 7

Due to “trigger happy patient

Question 8

Centrally one expects a threshold of lower…………

Peripherally one expects a threshold of

Answer 8

• 30’s dB generally (rule of thumb).

- upper 20’s dB generally (rule of thumb)

Question 9

On total deviation plot scale, what consider abnormal

Answer 9

Any point that is -5db or less (-8,-7,-8) is suspicious

Question 10

Mean Deviation plot

Answer 10

MD deviation range from + value to – value
High positive –>person clicking a lot
If P value next to it, then chance of abnormality.
A positive number indicates an average sensitivity is above-average normal for age
A negative number indicates an average sensitivity is below-average normal value for age

Question 11

PSD-pattern deviation

Answer 11

Helpful in identifying early defects

Ranges from zero, to high plus, back to zero
Zero value >Could be a good eye or blind eye, Look at the raw data, if it is all zero >blind
zero mean no pattern
High plus value >lot of defect and there is pattern to zero
Completely black >no pattern, back to zero means lot of damages..

Question 12

GHT

Answer 12

Outside normal limits (p

Question 13

To identify cluster, use number 7

Answer 13

Superior or inferior (treat them separately)
2-3 points next two each other with a defect
The 2-3 points need to be on the SAME hemifield (superior OR inferior) because each hemifield is supplied by a different set of nerves

Question 14

Staging MD

Answer 14

Mild= Better than-6 db
Moderate= Worse than -6.o dB but better than -12 dB 
severe = Worse than -12.0 dB

Question 15

high association with ipsilateral glaucoma

Answer 15

Port wine stain rarely associated with sturge-weber syndrome

Question 16

common signs of Pigmentary Dispersion Glaucoma

Answer 16

• TID
• Krukenberg’s spindle ( vertical lines of pigments on the endothelium)
• risk of glaucoma at 5 years is 10% and 15 years is 15%

Question 17

NTG has highest prevalence among….

Answer 17

Japanese patients.

Question 18

NTG risk factors

Answer 18

vascular disorders
Raynaud's phenomenon
migraines
low BP
sleep apnea
hypercoagulation

Question 19

PACG caused form

Answer 19

• Pupillary Block

- plateau Iris syndrome

Question 20

Topamax causes …

Answer 20

secondary angle closure.

Question 21

Secondary OAG

Answer 21

• Pseudoexfoliation Syndrome
• Pigmentary Dispersion Glaucoma
• Angle recession Glaucoma
• Normal Tension Glaucoma

Question 22

Secondary Angle Closure Glaucoma

Answer 22

• Neovascular Glaucoma

- uveitic Glaucoma

Question 23

Most important sign for NV Glaucoma is

Answer 23

-Rubeosis of the iris

Question 24

What is Buphthalmos

Answer 24

enlarged eye occurs by one year of age in patients with congenital glaucoma

Question 25

Inflammatory Glaucoma

Answer 25

• Glaucomatocyclitic Crisis ( Posner-Schlossman syndrome)
• Fuch’s heterochromic iridocyclitis
• Phacolytic Glaucoma

Question 26

False Positive

Answer 26

Poorly instructed patient
Expectancy of a stimulus to be present
A noise of shutter in the machine may be perceived as a stimulus presentation
Trigger happy patient

Question 27

False negative error

Answer 27

Proportion of visible stimuli to which the patients fail to respond.
Stimuli are presented at a location 9 dB brighter than previously “seen level” to which the patient response is “cannot see”