L27

Question 1

Glaucoma

Answer 1

Permanent vision loss due to increased intra-ocular pressure (inflow of aqueous production is greater than outflow) –> obstruct blood flow to the optic nerve –> ischemia of nerve –> permanet damage –> loss of vision

Question 2

Open angle glaucoma

Answer 2

• Angle width between cornea and iris
• Usually mid ocular pain, headache and halos
• Danger signals:
  (i) blurred vision that clears up after a while
  (ii) eyeglasses don’t classify vision
  (iii) rainbow rings around lights
  (iv) narrowed vision
  (v) difficulty adjusting to darkened rooms

Question 3

Angle closure glaucoma

Answer 3

Iris lies too close to the drainage canal and bulge forward against the cornea
–> block the outflow of aqueous humor
Clinical manifestations:
- IOP rises suddenly, ocular pain
- red eyes, clouding of iris (inflammation of cornea)
- blurred vision
- nausea and vomiting

Question 4

Medications that decrease the production of aqueous humour

Answer 4

1. Beta-blocker (non-selective)
   - avoid if patient has asthma, COPD or heart disease
   - decrease production of aqueous humor –> lower intraocular pressure
2. Carbonic anhydrase inhibitor
   - monitor diuretics effect: renal function and dehydration
   - decreased production of aqueous humor
3. Cosopt, combined eye drops
4. Alpha-adrenergic agoinists

Question 5

Medications that facilitating the drainage of the aqueous humor (for open-angle only)

Answer 5

1. Prostaglandin agonist (eye drop)
2. Miotics
   - stimulate contraction of the ciliary muscle to incease aq humor outflow
   - the pupil will constrict –> reduce the adaptation to the dark

Question 6

Medications for acute angle closure attack

Answer 6

(for immediate lowering IOP)
1. Carbonic anhydrase inhibitors
2. Hyperosmotic agents
(for long term treatment)
3. Laser peripheral iridotomy or surgical iridectomy

Question 7

Clinical manifestations of cataract

Answer 7

1. Photophobia (light seems to be very bright)
2. Poor night vision
3. Color seem to fade
4. Diplopia
5. Cloudiness of the lens

Question 8

Diagnostic test for cataract

Answer 8

1. Snellen visual acuity test
2. Opthamoscopic examination (dilate pupil with a slit lamp)
   - exact location of the cataract
   - the extent it blocks light

Question 9

Phacoemulsification

Answer 9

1. Lens is removed in pieces after being broken up by ultrasound
2. Small incision is made to cornea to suck up the small pieces
3. Self-sealing of the cornea

Question 10

Extracapsular extraction

Answer 10

1. Lens is removed in one piece
2. Large incision on the side of the cornea
3. Remove a circular anterior portion of the lens capsule
4. Suture to close the corneal incision

Question 11

Pre-op care for cataract surgery

Answer 11

1. Withhold anticoagulation therapy
2. Withhold aspirin for 5-7 days
3. Withhold NSAID for 3-5 days
4. Administer mydriatic agents (alpha-adrenergic agonist): dilate the pupil by relaxing the ciliary muscle
5. Administer cycloplegic agents (anticholinergic): short acting mydriasis and paralysis of accomodation
6. Administer corticosteroids: to reduce swelling and inflammation
7. May administer prophylactic antibiotics
8. Instruct patient to wear dark glasses to minimize photophobia
9. Monitor s/s of systemic toxicity (tachycardia and CNS effect)

Question 12

Post-op care for cataract surgery

Answer 12

1. Keep head elevated
2. Maintain the eye patch in place for 24 hrs after surgery
3. Administer miotic eye drops to constrict pupil and decreased lens dislocation
4. Avoid coughing, bending over, etc that increased intraocular pressure

Question 13

Home care after cataract surgery

Answer 13

1. Vision stabilization within 6-12 weeks
2. Wear eyeglasses during daytime
3. Use aseptic technique to apply eye drop
4. Consult doctor if experience s/s of retinal detachment
   - new floaters in vision
   - flashing light
   - decreased in vision
   - pain or increase in redness

Question 14

S/s of retinal detachment

Answer 14

1. Flashes or colored light
2. Black spot
3. Shadow drawn from the side of the visual field
4. Late sign: cloudy vision or loss of central vision

Question 15

Diagnostic test for retinal detachment

Answer 15

1. Stereoscopic indirect ophthalmoscope
2. Ultrasound

Question 16

Treatment of retinal detachment

Answer 16

1. Laser beam
2. Cryotherapy
3. Scleral buckling

Question 17

Post-op care for retinal detachment

Answer 17

1. Head position prevent pull of gravity from disrupting the surgical site
2. Position the oil or bubble at the best place to apply pressure to the retina
3. Monitor IOP closely for the first 24 hrs
4. Administer eye drops and antibiotics ointment as prescribed
5. Pain relief: cold pad, panadol
6. Observe sign of infection: severe pain, foul smell discharge or with greenish tinge (normal is yellowish or pinkish tinge)