OCULAR PHARMACOLOGY II

AntiglaucomaMydriatic & cycloplegic

Ocular toxicity of systemic & ocular medications -DR. T.

KurinjhiAsst.Prof.

Ophthalmology

AntiglaucomaAIM - lowering of IOP to levels that permit

normal functioning of optic nerve

PARASYMPATHOMIMETICS

Pilocarpine (2% - 4%) 6-8 hrly, ocuserts

MOA: contraction of longtitudinal fibres of ciliary muscle : pull on scleral spur & widen TBM spaces.

pull peripheral iris away from angle structures

Miosis, brow ache, accomodative spasm

SYMPATHOMIMETICS

Non selective - epinephrine(1%), dipivefrine(0.1%)MOA: increase rate of aqueous outflowStinging, reactive hyperemia, adrenochrome

deposits, CME

Selective – α1& α2 : apraclonidine (0.25%-1%) α2 : brimonidine (0.15%-0.2%)MOA: Decrease aqueous production, increase

uveoscleral outflow, increase optic nerve head perfusion

Ocular allergy, conjunctival blanching

ADRENERGIC ANTAGONISTS(ß blockers)

Non selective – timolol (0.25%-0.5%), levobunolol (0.25%-0.5%)

MOA: reduce rate of aqueous production.Tachyphylaxis, dry eye, bradycardia, bronchial

spasm

Selective – (ß1) betaxolol (0.25%-0.5%)MOA: reduce rate of aqueous production increase perfusion of optic nerve headStinging sensation, local anesthesia

PROSTAGLANDIN ANALOGUES

Latanoprost (0.005%) OD, unoprostone(0.12%), bimatoprost(0.03%), travoprost (0.004%).

MOA: increase uveoscleral outflow

Conjunctival hyperemia, SPK, iris pigmentation

CARBONIC ANHYDRASE INHIBITOR

Acetazolamide (oral-1gm/day), dorzolamide (topical 2%) brinzolamide (topical 1%)

MOA: reduces aqueous production

Altered taste, paresthesia, loss of appetite, depression, metabolic acidosis.

HYPEROSMOTIC AGENTS

Mannitol (5%-25%,1%-2% intravenous), glycerol (1-1.5 gm/Kg BD/TDS oral)

MOA: lower IOP by reducing vitreous volume

Not suitable for diabetics, uncontrolled hypertensives, pul.odema, cardiac/renal failure.

Mydriatic & cycloplegic

SYMPATHOMIMETICSDilate pupilPhenylephrine (5%-10%)

ANTICHOLINERGICS / PARASYMPATHOLYTICS

Dilate pupil, impair accomodationAtropine (1%), homatropine (2%),

cyclopentolate(1%), tropicamide (0.5%)

Fundus examinationTo measure objective refractive error

of the eyeHeadaches, latent hypermetropiaSuspected malingering or hysteriaPharmacologic occlusion therapy in

amblyopia

• Narrow anterior chamber angle – ACG

• Toxicity : fever, skin rash, rapid and irregular pulse, dry mouth and nose, and delirium

• Systemic toxicity - death, from an idiosyncratic response.

Ocular toxicity of systemic &

ocular medications

Corticosteroids Long-term use produces:• posterior subcapsular cataracts, (especially in

asthmatics, renal-transplant recipients and with rheumatic arthritis)

• increased IOP (steroid-induced glaucoma)• exacerbation of bacterial and viral infections• scleral melting

NSAIDs• corneal complications: melting

perforation

AmiodaroneCardiac arrhythmia drugWhorl shaped pigment deposits in corneal

epithelium – cornea

verticillata Deposits are dosage related and reversible

ChloroquineChloroquine and hydroxychloroquinemalaria, rheumatoid arthritis, lupus, autoimmune diseasescorneal deposits (cornea verticillata) - reversible macular lesion (bull’s eye maculopathy) - not reversible

Diphenylhydantoin

Antiepileptic

Dose-related cerebellar-vestibular effects (e.g.,nystagmus, diplopia)

Complex forms of nystagmus and ophthalmoplegia

All reversible effects

Ethambutol

TuberculosisDosage related optic neuropathy• 15mg/kg/day: optic neuropathy in 1%• 25mg/kg/day: optic neuropathy in 5%• 50mg/kg/day: optic neuropathy in 15%

Onset in 1 monthRecovery on discontinuing of drug ;

rarely permanent

ThioridazineAnti-psychoticPigmentary retinopathy after high dosage (usually at least

1000 mg/day) Current recommendation is a maximum dose of 800

mg/day

Thank You

Anti-inflamatory

CorticosteroidsNSAIDSMast-cell stabilizers, Antihistamines,Antifibrotics

Corticosteroids – systemic, topical - drops, ointment, subconjunctival injections, subtenon’s injection, intravitreal injections /

implants.uveitispost ocular surgical procedures ocular inflammation in traumaoptic neuritis systemic immune diseases with severe

ocular inflammationsPrednisolone; dexamethasone; fluromethalone;

loteprednol

NSAIDS – systemic, topical -drops, ointment

anterior segment inflamation, prophylaxis of CMEReduces intraoperative miosispostoperative inflammation allergic conjunctivitis

Indomethacin, Flurbiprofen, Ketorolac, Diclofenac, Nepafenac and Bromfenac