Glaucoma

Question 1

What secretes aqueous secretion?

Answer 1

non-pigmented ciliary epithelium

Question 2

What forms the major proportion of resistance to aqueous outflow?

Answer 2

-> juxtacanalicular meshwork (outer part of trabecular meshwork)

Question 3

Describe the aqueous outflow

Answer 3

1. trabecular -> 90% through trabeculum into Schlemm canal and then drained by episclera veins
2. Uveoscleral route -> 10% aqueous passes across the face off the ciliary body into suprachoroidal space

Question 4

N.R. of IOP

Answer 4

11-21 mmHg
-> normal IOP varies within 5mmHg daily with time/ heartbeat, BP, Respiration

Question 5

Define Glaucoma

Answer 5

needs 3:
1. intraocular pressure (high, normal, or low)
2. optic neuropathy
3. visual field loss

Question 6

RF of Glaucoma?

Answer 6

• high IOP
• Corticosteroids
• Central retinal vein occlusion
• FH
• Uveitis
• Myopia
• DM
• Insufficient blood circulation
• CT abnormalities

Question 7

How to diagnose glaucoma?

Answer 7

• Tonometry
• Pachymetry (thickness of cornea)
• Gonioscopy
• Fundus examination
• Visual field test
• Optical coherence Tomography
• Scanning Laser Poplarimetry
• Scanning Laser Ophthalmoscopy

Question 8

What is the G.S. for diagnosis of Glaucoma?

Answer 8

Goldmann Tonometry

Question 9

What is the most anterior structure of angle structures?

Answer 9

Schwalbe line

Question 10

Define evaluation of optic nerve head in regards to Glaucoma

Answer 10

Neuoretinal rim: tissue btw. outer edge of cup and disc margin
-> normal: c/d ratio of 0.3 or less (cup/ disc)
-> asymmetry of 0.2 or more -> susp. of Glaucoma until proven otherwise

Question 11

Symptoms + RF of open- angle Glaucoma

Answer 11

RF:
-Age (>65 more common)
-Race (blacks)
-FH (if FH screen from age of 40)
-Dm
-reduction of rerfusion pressure
-myopia
-retinal disease (CRVO, rhegmatogenous RD, RP)

Symptoms:
-Initially often asymptomatic
-mild headaches, impaired adaptation to darkness
-Generally bilateral, progressive visual field loss (from peripheral to central)

Question 12

First sign of visual defect in glaucoma

Answer 12

paracentral (commonly supero-nasally)

Question 13

Define grading of glaucomoatous dmagae

Answer 13

1-4
1: mild
4: end-stage

Question 14

Define CF of acute-angle closure glaucoma + RF

Answer 14

-Sudden onset of symptoms
-Unilaterally inflamed, reddened, and severely painful eye (hard on palpation)
-Frontal headaches, vomiting, nausea
-Blurred vision and halos seen around light
-Mid-dilated, irregular, unresponsive pupil
-Complications: rapid permanent vision loss due to ischemia and atrophy of the optic nerve

RF:
-age, fh, female, race (chinese, south-east asians, eskimos)

Question 15

What is Normal tension Glaucoma (NTG)?+ RF

Answer 15

it is:
-mean IOP< 21mmHg
-VF floss
-Open drainage angle

RF:
age
japan
female
fh

Question 16

what are systemic association with NTG

Answer 16

raynaud (peripheral vascular spasm on cooling)
migraine
nocturnal systemic hypotension

Question 17

What should you know about Pseudoexfoliation?

Answer 17

-> matrix material
-common in scandinavia
-in femal more present but males at higher risk of glaucoma
-present with chronic open angle glaucoma
-medical tratment
-laser trabeculoplasty

Question 18

What are the two types of traumatic glaucoma?

Answer 18

-red blood cell glaucoma: blood clot obstructs trabecular meshowrk, hyphema (>1/2): tx: medical, ant. chamber washout

-angle recession glaucoma: previous blunt trauma, rupture of the face of the ciliary body; tx: medical, trabeculectomy (antimetabolite)

Question 19

What can be the cause of congential glaucoma+ classification

Answer 19

trabeculodysgenesis
class:
- congenital glaucoma (intrauterine high IOP)
- infantile glaucoma (until 3 years of age)
- Juvenile glaucoma (3-16 years)

-> bilateral

Question 20

Presentation of cong. glaucoma

Answer 20

corneal haze, epiphora, photophobia, blepharospasm

findings: buphthalmus, Haab’s stria (ruptured descement membrane)

Question 21

DDx of cong. glaucoma

Answer 21

Birth trauma
intrauterine rubella infect.
metabolic disease
cong. hereditary endothelial dystrophy
megalocornea
nasolacrimal canal obstruction
sec. infantile glaucoma (retinoblastoma, retinopathy of prematurity, intraocular inflammation, ectopia lenitis, etc.)

Question 22

Tx of Glaucoma

Answer 22

-Medical (topical, systemic)
-laser (laser trabeculoplasty, argon laser trabeculoplasty, selective laser trabeculoplasty, etc.)
Surgery

Question 23

Describe medical tx of glaucoma

Answer 23

Topical:
-beta blockers (timolol, betaxolol) ->deac. aqueous secretion
-alpha2.adrenergic agonists (brimonidine, aproclonidine, etc.) -> deac. aqueous secretion & incr. uveoscleral outflow
- parasympathomimetics (pilocarpine) -> incr. trabecular outflow (in open angle) + withdrawl of iris from trabeculum (in closed-angle)
- carbonic anhydrase inhibitors (dorzolamide, brinzolamide, acetazolamide) -> decr. aqueous secretion

systemic:
for closed angle
-carbonic anhydrase inhibitors -> decr. aqueous secretion
- osmotic agents