Glaucoma

Question 1

Optic nerve head changes

Answer 1

• Decreased blood flow can destroy axonal tissue
• Compression, necrosis of axonal tissue
• Cup to disc ratio of 0.5 (mild-moderate)
• Cup to disc ratio of 0.9 (severe)
• As axons die off, cupping increases

Question 2

IOP

Answer 2

Intraocular pressure

• Prevents cornea; collapse
• Prevents damage to the optic nerve
• The higher the IOP the greater the risk for glaucoma
• AH dynamics/IOP: only clinically modifiable risk factor

Question 3

POAG risk factors

Answer 3

• Elevated IOP (>21 mmHg)
• Age (>60, >40 for black patients)
• Family history/genetics
• Race, ethnicity (black, hispanics)
• Inc cup to disc ratio
• CCT thinner
• Ocular perfusion pressure (lower=more risk)
• T2DM
• Myopia (can’t see far)

Question 4

Goals of treatment

Answer 4

• Preserve the nerve
• Lower IOP
  
  • control of target pressure >= 25% below pretreatment IOP

Question 5

Prostaglandin analogs (POAG)

Answer 5

• Best 1st line option in most cases
• Reduce IOP 25-33% using 1 drop a day
• Bimatoprost, Latanoprost, Travoprost
• AE: Hair growth (hypertrichosis), conjunctival hyperemia, iris pigmentation changes
• CI: existing ocular inflammation (keratitis, iritis, uveitis, macular edema)

Question 6

Beta-blockers (POAG)

Answer 6

• Decrease AH production
• Reduce IOP 20-25%
• Betaxolol, Carteolol, Levobunolol, Metipranolol, Timolol
• AE: local irritation, cardiac/pulonary/CNS effects, tachyphylaxis
• CI: sinus bradycardia, heart block, HF, pulmonary disease

Question 7

alpha 2-adrenergic agonists

Answer 7

• reduce AH production by the ciliary body
• Reduce IOP 20-25% (most cases less than 20%)
• Not recommended as single agent
• AE: local irritation, allergic rxns, conjunctival hyperemia, drowsiness, dry mouth, tachyphylaxis
• Precautions: cardiovascular diseases
• Brimonidine-timolol combo: as effective as lantanoprost

Question 8

Carbonic anhydrase inhibitors

Answer 8

-Use as add on drugs
_reduce AH production by the ciliary body via dec in bicarbonate ion secretion
-Reduce IOP 15-20% (topical), 20-30% (oral)
_drugs: acetazolamide, brinzolamide, dorzolamide, methazolamide

Question 9

Dorzolamide/Timolol combo

Answer 9

• No significant difference in lowering IOP than latanoprost

- Versus bimatoprost, no significant difference in lowering IOP

Question 10

RHO kinase inhibitor

Answer 10

• about 20% IOP decreases if IOP <27 mmHg
• high rate of undesirable side effects
• add on drugs

Question 11

Time to follow up (glaucomatous progression)

Answer 11

1-2 months

Question 12

Time to follow up (no glaucomatous progression)

Answer 12

6 months

Question 13

OHTS

Answer 13

• Not all patients should receive drugs
• Only patients with elevated IOP and confirmed disc changes/field defects
• Those with OH and risk factors such as ethnicity, family history, large cup to disc ration, high IOP)

Question 14

N-T glaucoma

Answer 14

• treat all patients with elevated IOP and confirmed disc changes/field defects
• Those with OH and risk factors
• Those with NTG and documented progression of visual field loss

Question 15

PACG

Answer 15

• Pupillary block
• Lens thickening
• Medical emergency
• Wild IOP fluctuations
• Vision won’t come back
• Goal: medically break attack quickly to preserve vision and prep eye for laser peripheral iridotomy

Question 16

PACG IOP

Answer 16

• Carbonic anhydrase inhibitors (IV or PO)
• Beta blockers (topical)
• alpha-agonists (topical)

Question 17

PACG angle

Answer 17

pilocarpine

-induces missos

Question 18

Acute angle closure crisis

Answer 18

• IV or PO carbonic anhydrase inhibitor (Acetazolamide)
• Beta blocker
• Alpha agonist (Apraclonidine)
• Pilocarpine