Drugs

Question 1

Mydriatics:

atropine: slow and long
homatropine:
cyclopentolate
tropicamide: quickest and shortest

reading returns before accommodation

Answer 1

dilation + cycloplegia (ciliary paralysis)
SE: PACG risk from dilatation; reading/accommodation

diagnosis: examination (lens, vitreous, fundus); refraction (cycloplegia)
treatment: iritis/iridocyclitis, corneal epithelial, photophobia (ciliary spasm), posterior synichae prevention

Question 2

Myotics (parasympathomimetics)

Answer 2

constriction, reduce IOP (angle)
SE: cyclotonia (ciliary spasm) - headache + blurry

pilocarpine: glaucoma, constriction; direct sphincter/ciliary action
acetylcholine (very short)/carbachol (longer): choline esters
antiChE: eserine (short), phospholine (long)

Question 3

Glaucoma - actions

*Xalacom = latanoprost + timolol)

Answer 3

topical:

• Alpha2-agonist (‘inide’): outflow, production
• BB (‘olol’): production
• carbonic anhydrase inhibitors (‘lamide’): production
• PG analogues (‘prost’): outflow
• miotics (pilocarpine): outflow

systemic: acetazolamide (CAI); toxicity risk

Question 4

ABx

Answer 4

top chloramphenicol: broad, static; conjunctivitis, trauma/viral (PPx)
-SE: allergy, aplastic anaemia/BMS, leukaemia, grey baby (IV)

2nd line: gent, neomycin, o/norfloxacin (quino), soframycin

cefuroxine/ciprofloxacin: severe corneal infection

Question 5

Anti-allergy

Answer 5

comoglicate: severe allergic conjunctivitis
otrivine: antiH+vcon: mild allergic conj; rebound congestion risk
lodaxamide, nedocromil: antiinflam; allergic/viral conjunctivitis
anitH mast cell stabilisers (‘istines’)

Question 6

Steroids

Answer 6

topical: anterior inflmmation (blepheritis, catarrh, iritis, corneal)
- SE: infection, HSK worse, slow healing, ^IOP, cataracts

systemic: deep inflammation (ciliary, choroid, retina, nerve, thyroid, GCA/AAION)
- SE: weight/DM, HTN, cataracts, glaucoma
- steroid sparing anti-inflamm e.g. CsA, cyclophosphamide

Question 7

Tear Substitutes

Answer 7

hypromellose: cheap; simple cases
liquifilm (polyvinyl): mucus deficiency
Tears Naturale: dextran + hypromellose; 2nd line
Carbomer 980/viscotears/gel
acetylcysteine: mucolytic; combo hypormellose

use >4/d = refer, ?Sjogren’s

Question 8

Diagnostic Agents

LA: onset minutes, duration 30m (proxy) to 4h (ligno)
cocaine: strong, rapid; dilatation, confusion/delirium, cloudy corneal epithelium
amethocaine: rapid, no dilation but sting + vdil
benoxinate: slow but no irritation
proxymethocaine (ophthaine): rapid, short, weak, no sting
lignocaine: longer
oxybuprocaine

Answer 8

fluorescein: corneal/epithelial damage
fose bengal 1%: damaged cells, cornea/conjunctivae
Local anaesthetics: block pain e.g. tonometry
-surgery, tonometry, gonioscopy, CL fitting, pain relief, NaFl exam
-SE: irritation/sting, blurry, injection (vdil), epithelial toxicity, inhibited healing

Question 9

Contact Lenses

Answer 9

Soft: better fit, easier use, secure but dehydrates, tear deposits, splits
Hard: fixed, durable, better vision; but initial discomfort, less secure
-esp. keratoconus/grafts

Question 10

Drugs Affecting the Eyes

Answer 10

chloroquine
ethambutol
chlorpromazine
tamoxifen
digoxin

Question 11

Corneal Protection

Answer 11

lubrication
chloramphenicol ointment (PPX)

Question 12

Glaucoma - SE

Answer 12

AA: burn/string, headache, drowsy, dry mouth/nose; allergy risk
BB: BP, HR, SOB, fatigue
CAI: systemic toxicity; paraesthesia, malaise, confusion, abdo/renal
PG: red eye, pigmentation, thick lashes, pain/irritation, dry eye, headache, photophobia
pilocarpine: dim vision, pain, headache (spasm), retinal detachment; avoid in uveitis

Question 13

aciclovir:

active: 400mg 5/d active
PPX: 2/d for 12 months

Answer 13

viral TK allows monophosphate version; inhibits HSV DNA polymerase

SE: GI upset, nephrotox, SJS/TEN risk, cell counts
topical irritation, erythema, supf punctate keratitis