BCSC 10. Glaucoma

Question 1

Critical risk factors for progression of POAG

Answer 1

DECREASED PERFUSION PRESSURE, thin cornea, increasing age. Intracranial pressure not studied. Low ICP implicated in low-tension glaucoma.

Question 2

Inheritance of axenfeld-rieger syndrome

Answer 2

AUTOSOMAL DOMINANT

Question 3

Outflow facility is measured by

Answer 3

tonography

Question 4

Measures aqueous humor formation rate

Answer 4

fluorophotometry

Question 5

Measures episcleral venous pressure

Answer 5

venomanometry

Question 6

Must be calculated using goldman equation and parameters IOP, aqueous humor flow rate, outflow facility, and episcleral venous pressure

Answer 6

Uveoscleral outflow rate

Question 7

Rate of aqueous humor formation during sleep

Answer 7

decreases 50%. Normal 2-3uL/min

Question 8

Tonometer uses Imbert-Fick principle for measurement of IOP

Answer 8

Goldmann and Perkins tonometer - use same measurement tip, balances surface tension of tear film with rigidity of cornea to approximate dry infinitely flexible thin walled sphere for eyes with corneal thickness of 520 um

Question 9

Imbert-Fick principle

Answer 9

relates pressure inside a dry, thin-walled sphere to the force required to flatten a specific area

Question 10

Force goldmann applanation tonometer measures

Answer 10

Force necessary to flatten an area of the cornea of 3.06 mm in diameter

Question 11

How was a visual field defect defined on standard automated perimetry in the OHTS

Answer 11

presence of a Pattern Standard Deviation (PSD) with P < 5% or presence of a Glaucoma Hemifield Test (GHT) with a result outside normal limits. Had to be present in 3 consecutive visual field tests

Question 12

Mutations in which gene are associated with pseudoexfoliation syndrome?

Answer 12

LOXL1 mutation at 15q24 (Scandanavians like lox)

Question 13

Gene mutation in primary congenital glaucoma

Answer 13

CYP1B1

Question 14

Gene mutation in iridogoniodysgenesis

Answer 14

FOXC1

Question 15

Gene mutation in Rieger syndrome

Answer 15

PITX2

Question 16

m/c cause of glaucoma associated with primary or metastatic tumors of the ciliary body

Answer 16

DIRECT INVASION of the anterior chamber angle

Question 17

Glaucoma caused by leakage of lens protein through the capsule of a mature or hypermature cataract

Answer 17

Phacolytic glaucoma - phagocytizing macrophages obstruct TM

Question 18

Glaucoma caused when lens cortex particles obstruct TM following disruption of lens capsule with cataract extraction or trauma

Answer 18

Lens particle glaucoma

Question 19

Glaucoma caused by large intumescent lens induces angle-closure (ACG)

Answer 19

Phacomorphic glaucoma

Question 20

Displacement of lens from its normal anatomical position

Answer 20

Ectopia lentis

Question 21

WDR36

Answer 21

Adult POAG

Question 22

OPTN

Answer 22

NTG, adult POAG

Question 23

TIGR/MYOC

Answer 23

JOAG and adult POAG

Question 24

Inheritance of Congenital glaucoma

Answer 24

Recessive

Question 25

Goldmann equation

Answer 25

``` Po = (F-U)/C+Pv Po = IOP in mm Hg F = rate of aqueous formation in uL/min U = rate of aqueous humor drainage through pressure insensitive uveoscleral pathway (uL/min) C = outflow facility Pv = episcleral venous pressure in mm Hg ```

Question 26

Resistance to outflow (R) is equal to

Answer 26

inverse of facility of outflow

Question 27

Aqueous humor composition

Answer 27

XS Hydrogen, chloride, ascorbate, deficit of bicarb, protein free (1/200-1/500). GF, enzymes: carbonic anhydrase, lysozyme, diamine oxidase, plasminogen activator, dopamine beta-hydroxylase, phospholipase A2, prostaglandins, cyclic adenosine monophosphate, catecholamines, steroid hormones, hyaluronic acid

Question 28

Bilateral angle closure glaucoma in eyes with normal axial length

Answer 28

Uveal effusions due to systemic medication - m/c topiramate

Question 29

Laser iridotomy useful for

Answer 29

pupillary block (phacomorphic glaucoma)

Question 30

Patients with appositional angle closure or areas of peripheral anterior synechiae with relative pupillary block are at risk for chronic angle closure developing should have this treatment

Answer 30

laser iridotomy

Question 31

Elevation of IOP independent of pupillary block may occur despite a patent iridotomy

Answer 31

Plateau iris syndrome

Question 32

Type of glaucoma unlikely to resolve after cataract extraction

Answer 32

Eye with angle recession and phacodenesis after blunt trauma

Question 33

Abnormal spherical shape of lens induces pupillary block

Answer 33

microspherophakia

Question 34

Finding in congenital glaucoma can continue to change and indicate progression even though IOP appears to be controlled

Answer 34

AXIAL LENGTH

Question 35

After successful surgery for congenital glaucoma, how many years should child be monitored

Answer 35

Lifetime

Question 36

Post-op complications in congenital glaucoma

Answer 36

amblyopia, strabismus, corneal decompensation, cataracts

Question 37

Glaucoma medication contraindicated in toddlers

Answer 37

Brimonidine - systemic hypotension and apnea in children younger than 2 years old. Relative contraindication in older children

Question 38

Class of ocular hypotensive agents associated with the development of apnea in infants and young children

Answer 38

alpha 2-Selective adrenergic agonists reported to cause systemic hypotension, apnea, CNS depression, bradycardia. May cross blood-brain barrier. Avoid in nursing mothers.

Question 39

Only topical ocular hypotensive beta-blocker that is relatively beta-1 selective

Answer 39

Betaxolol

Question 40

Nonselective beta-adrenergic antagonists (beta-blockers) topical ocular hypotensive agents

Answer 40

Timolol, carteolol, levobunolol (may result in bronchospasm)

Question 41

Conditions associated with increased risk of suprachoroidal hemorrhagw

Answer 41

High myopia, aphakia or pseudophakia, hypotony, prior vitrectomy, advanced age, systemic hypertension, anticoagulant therapy, h/o suprachoroidal hemorrhage in fellow eye.

Question 42

Fluorouracil Filtering Surgery Study found that risk of suprachoroidal hemorrhage was strongly associated with

Answer 42

(1) level of preoperative IOP and (2) magnitude of IOP reduction. Reduce IOP as much as possible before filtering surgery and decreasing magnitude of immediate IOP reduction through releasable sutures or laser suture lysis can reduce risk.

Question 43

5 years after laser trabeculoplasty, what percentage of treated patients are expected to maintain lower IOP

Answer 43

50%

Question 44

Best candidate for a trabeculectomy with mitomycin C

Answer 44

Patient with previous failed trabeculectomy without antifibrotics

Question 45

Patient with neovascular glaucoma is candidate for which GL procedure

Answer 45

Tube shunt (trabeculectomy success rate lowered with inflammation)

Question 46

Patient with active uveitis or neovascular glaucoma is good candidate for which GL tx

Answer 46

Tube shunt (trabeculectomy success rate lowered with inflammation)

Question 47

Risk factor for bleb related infections

Answer 47

contact lens wear

Question 48

Patient with most success with laser trabeculoplasty (LTP)

Answer 48

IOP needs to be lowered but patient can't tolerate multiple medications. Contraindicated in uveitic glaucoma.

Question 49

LTP less effective in which patients

Answer 49

Less effective in aphakic and pseudophakic than in phakic patients. Small central island of vision is at risk of vision loss if significant IOP spike

Question 50

Consider tube shunt in following clinical settings

Answer 50

``` Failed trabeculectomy with antifibrotics Active uveitis Neovascular glaucoma Inadequate conjunctiva Aphakia CL use ```