Glaucoma

Question 1

Inheritance of juvenile open-angle glaucoma

Answer 1

Autosomal dominant (myocilin/TIGR gene)

Question 2

When no other family history of primary congenital glaucoma exists, what is the chance that an affected parent will have an affected child?

Answer 2

<5% (usually sporadic, but can be inherited in autosomal recessive fashion)

Question 3

Only selective beta-1 antagonist

Answer 3

Betaxolol

Question 4

UBM versus B-scan:

• wavelength
• scleral penetration
• resolution

Answer 4

Shorter wavelength
Less scleral penetration
Increased resolution

Question 5

Mechanism of iris color change with topical prostaglandin use

Answer 5

Increased number of melanosomes within melanocytes

Question 6

What conditions lower IOP? (4)

Answer 6

Aerobic exercise
Pregnancy
Alcohol use
Marijuana use

Question 7

Optic disc findings suggestive of glaucomatous optic neuropathy

Answer 7

Vertical cup elongation, rim notching, cupping to rim margin
Exposed lamina cribrosa
Nasal vessel displacement
Baring of circumlinear blood vessels
Beta zone peripapillary atrophy

Question 8

What IOP lowering agent may precipitate keto acidosis in patients?

Answer 8

Glycerol

Question 9

In the TVT 5-year follow-up study, eyes with previous intraocular surgery had highest success rate with what glaucoma surgery?

Answer 9

Baerveldt (both trab and Baerveldt lowered IOP similarly, but Baerveldt required fewer additional surgical procedures)

Question 10

Elevation of IOP associated with uveitis can be related to what? (4)

Answer 10

Elevation of IOP associated with uveitis can be related to trabecular inflammation, cellular trabecular obstruction, corticosteroid-induced ocular hypertension, and occlusio pupillae with synechial angle closure.

Question 11

What class of glaucoma medications should be avoided during pregnancy?

Answer 11

Prostaglandin analogs (induce uterine smooth muscle contraction)

Question 12

How is uveoscleral outflow affected by age, pressure, and cycloplegia?

Answer 12

Decreases with age and in glaucoma patients
Pressure-insensitive
Increased by cycloplegia (also adrenergic agents, prostaglandin analogs)

Miotics decrease uveoscleral outflow

Question 13

What parameter of the modified Goldmann equation cannot be directly measured clinically and must be calculated? How are the other parameters measured? (4)

Answer 13

Uveoscleral flow rate

Intraocular pressure: tonometry
Outflow facility: tonography
Aqueous humor formation: fluorophotometry
Episcleral venous pressure: venomanometry

Question 14

What is the prevalence of glaucoma among siblings of glaucoma patients?

Answer 14

10%

Question 15

What mode of tonometry is less influenced by CCT? e.g. post-LASIK changes

Answer 15

Dynamic contour tonometry (contours to cornea instead of applanating it)

Goldmann more affected
Rebound (e.g. iCare) most affected

Question 16

Direct gonioscopy lenses (5)

Answer 16

Koeppe, Barkan, Wurst, Swan-Jacob, Richardson

Question 17

Indirect gonioscopy lenses (4)

Answer 17

Goldmann, Posner, Sussman, Zeiss

Question 18

Imbert-Fick principle for application tonometry

Answer 18

Pressure inside dry, thin-walled sphere related to force required to flatten specific area

Question 19

What iris color is least likely to darken with chronic prostaglandin use? Most likely?

Answer 19

Blue irides least likely (8%)

Green-brown/hazel most likely (85%)

Question 20

How does aqueous humor formation during sleep compare to during waking hours?

Answer 20

Decreases by 50% (waking hours 2-3 uL/min )

Question 21

What was most common cause of decreased vision in surgical arm of CIGTS?

Answer 21

Cataract formation

Question 22

What type of primary angle closure occurs independently of pupillary block?

Answer 22

Plateau iris syndrome

Question 23

What anesthetic has least effect on IOP? Increases IOP? Decreases IOP?

Answer 23

Chloral hydrate

Increase IOP: ketamine, succinylcholine (skeletal muscle relaxant)
Decrease IOP: sevoflurane