Ocular Dz 3-1

Front 1

The third leading cause of blindness in the US

Back 1

glaucoma
1st = Diabetes
2nd = AMD

Front 2

How many Americans are estimated to have glaucoma? How many with high IOP?

Back 2

at least 3 million with glaucoma, 6-12 million with high IOP

Front 3

What % of glaucoma is POAG

Back 3

70%

Front 4

How many people are legally blind due to glaucoma? Visual impairment?

Back 4

over 120,00 legally blind, 1.5 million with visual impairment

Front 5

What are the 4 categories of non-ocular risk factors?

Back 5

1. Age
2. Race
3. Family Hx of POAG
4. Systemic Health

Front 6

Why is age a risk factor?

Back 6

Over 40 is a risk factor, incidence of VF is 0.7% in those less than 40 and increases to 4.8% over age 60

Front 7

How does race act as a risk factor?

Back 7

African Americans > Caucasians > Asians
AA develop glaucoma at least a decade earlier than Caucasians and have more rapid progression. Blindness is 8xs higher in AA.

Front 8

Is gender a risk factor in glaucoma?

Back 8

Gender is not a risk factor

Front 9

How does a family Hx of POAG affect a patients risk?

Back 9

1st degree relatives have 3-5x higher risk of developing glaucoma, risk may be greater if a sibling has glaucoma

Front 10

What systemic health concerns are definite risk factors?

Back 10

Diabetes, Vascular dz, and Reynaud's syndrome (cold hands, warm heart)

Faster onset of glaucoma if diabetes, vascular dz, and/or HTN present. (BP does not result in high IOP though)

Smoking/alcohol use may damage nerves over time mimicking or precipitating glaucoma

Front 11

What are possible ocular risk factors for glaucoma?

Back 11

1. IOP over 21 mmHg
2. ONH changes
3. NFL changes
4. Myopia
5. Angle abnormalities
6. Corneal Thickness

Front 12

How does increased IOP affect risk of glaucoma?

Back 12

Increasing risk of POAG with increasing IOP
21-23 mmHg +
24-26 ++
27-29 +++
over 30 ++++

Front 13

How do changes in nerve fiber layer affect risk of glaucoma?

Back 13

A loss or defect in the NFL is a risk factor when associated with notching

Splinter Hemorrhage is also a risk factor when associated with NTG

Front 14

How do changes in the ONH affect risk of glaucoma?

Back 14

Good predictor of POAG
1. cup excavation
2. rim tissue loss
3. vertical cup elongation
4. asymmetric C/D
5. Peripapillary atrophy

Front 15

How does myopia affect risk of glaucoma?

Back 15

High myopes may have an increased risk (+/-)

Front 16

How do angle abnormalities affect risk of glaucoma?

Back 16

Gonioscopy may be done to detect abnormalities that cause various risk for glaucoma types (traumatic/neovascular)

Front 17

How does corneal thickness affect risk of glaucoma?

Back 17

Thinner corneas may be at a greater risk for glaucoma as they will give falsely low IOP readings as found by the OHTTS study

Front 18

Is glaucoma symptomatic or asymptomatic? multifactorial or unifactorial? polygenic or unigenic? acute or chronic?

Back 18

Glaucoma presents asymptomatically almost always, is multifactorial and polygenic, and is a chronic life-long condition.

Front 19

Is visual acuity affected by glaucoma?

Back 19

Usually VAs remain 20/20 unless the glaucoma is severe causing damage to the papillomacular bundle.

Front 20

Are the pupils affected with glaucoma?

Back 20

An RAPD is usually present but if the glaucoma affects both eyes it may be too small to notice as glaucoma is generally a bilateral, asymmetric condition.

Front 21

Corneal signs of glaucoma seen in slit lamp

Back 21

1. corneal endothelial pigment dusting may appear as a Kruckenberg's spindle --> pigmentary glaucoma
2. "Steamy" cornea with perilimbal injection may be a sign of acute angle closure
3. corneal opacities or global findings suggestive of penetrating injury --> traumatic glaucoma

Front 22

Signs of glaucoma seen in iris upon slit lamp exam

Back 22

1. iris retroillumination showing iris atrophy, heterochromia, rubeosis or corectopia --> sign of neovascular or pigmentary glaucoma
2. deposition of dandruff like material on iris --> pseudoexfoliative glaucoma
3. "Boggy" iris or posterior synechiae to lens --> angle closure

Front 23

Signs of glaucoma seen in the anterior chamber upon slit lamp exam

Back 23

anterior chamber angle depth and clarity --> angle closure

Front 24

Signs of glaucoma seen in the lens upon slit lamp exam

Back 24

1. Deposition of dandruff like material in a ring pattern on the anterior lens --> pseudoexfoliative glaucoma
2. Lens pigment, glaukomflecken, subluxed lens, or injury-induced cataract

Front 25

What is the standard tonometry technique?

Back 25

Goldmann (GAT)

Front 26

Is 21 mmHg an indicator of glaucoma?

Back 26

21 mmHg is the high end of normal - except that 4-5% of the normal population has IOPs above this without glaucomatous damage.

The higher the IOP the more suspicious you need to be for damage.

Front 27

POAG and IOP

__% of POAG pts have an IOP of less than ___ mmHg at screening.

At least ___ of POAG pts never have IOPs greater than ___ mmHg.

Back 27

50% of POAG pts have an IOP of less than 22 mmHg at screening.

At least 1/6 of POAG pts never have IOPs greater than 21 mmHg.

Front 28

What is the diurnal variation of glaucoma?

Back 28

IOP is often highest early in the morning and lower at night. Often POAG pts have an exaggerated diurnal variation so IOP should be checked earlier in the day.

Front 29

What is a pressure that is high enough to begin treatment without any other information?

Back 29

30 mmHg
The pachymetry should be checked to make sure a thick cornea isn't falsely causing the pressure to look high. The corneal curvature should also be checked.

Front 30

What method of IOP measurement takes CCT into account? Which method can be done to monitor pressures at home?

Back 30

Pascal DCT takes CCT into account.

Proview uses phosphine technology and may be used at home but is not too accurate.

Front 31

What pachymetry reading put the patient at higher risk? Lower risk?

Back 31

Higher risk is less than 555 microns

Lower risk is more than 588 microns

*Per OHTT study

Front 32

What disease could cause the IOP to be underestimated by Goldmann without any other test being done?

Back 32

An underestimated IOP = artificially low IOP, the cornea is then thinner than normal. This could be caused by keratoconus.

Front 33

What disease could cause the IOP to be overestimated by Goldmann without any other test being done?

Back 33

An overestimated IOP = artificially high IOP, the cornea is thicker than normal. This could be caused by Fuch's dystrophy.

Front 34

What is gonio used for?

Back 34

To determine the angle width, helps to determine secondary glaucomas as their may be multiple mechanisms for glaucoma.

Front 35

What should be used for ONH evaluation?

Back 35

standard magnified stereoscopic view with high plus (60-90 D) or contact fundus lens (like the center of the gonioscope.

Front 36

Why does the ophthalmoscope cause the C/D to be underestimated?

Back 36

The monocular view you get through the o-scope.

Front 37

What is the only disc change that is pathogomonic for glaucoma?

Back 37

Progressive thinning of the neural rim.

Front 38

What does the scleral canal determine?

Back 38

The disc size

Front 39

What is the range of normal disc diameters? What does a larger disc size create?

Back 39

normal = 1.33 - 2.66