Dr. Faizur Rahman Professor of Ophthalmolgy Peshawar Medical College Peshawar
At the end of the session the students would be able to: Know various antibiotics and steroids used in Ophthalmic practice. Describe the rationale of using various drugs. Mechanism of action, effects and side effects of these drugs. Know drug treatment of certain diseases
A chemical substance produced by one organism causing the death of other bacterial cells i.e penecillin and streptomycin. After the introduction of synthetic agents these are now called antibacterials. As newer agents came up now a wide spectrum of drugs are available called antimicrobials.
Difference between humans and microbes is exploited to produce substances toxic to microbes and harmless to humans. The selective toxicity may be relative than absolute. Concentration of antimicrobials must be carefully controlled.
Promote normal intermediary metabolism: Gluconeogenesis Stimulate protein catabolism Stimulate lipolysis Increase resistance to stress by: Raising blood glucose level Modest rise in BP Alter blood cell levels in plasma: Decrease in eosinophils, basophils, monocytes and lymphocytes by redistribution from circulation to lymphoid tissue Increase in the number of RBC, platelets, neutrophils
Anti inflammatory action: (Complex mechanism) Suppression of immunity Indirect inhibition of phospholipase A2 Alter other endocrine systems: Decrease in ACTH and TSH Increase in GH Effects on other systems: Increased production of gastric acid, pepsin Effects on CNS Bone loss Myopathy
In the treatment of ocular inflammations and immune related ocular diseases. Act by suppressing the formation of arachidonic acid and other mediators by induction mediators like phospholipaze A 2 and inhibitory protein Lipocorteins Prevent edema, Fibrin deposition, capillary dilatation and proliferation, Leukocyte infiltration and subsequent scarring.
Prenisolone (Topical and systemic) Dexamethasone (Topical and systemic) Betamethasone (Topical and systemic) Hydrocortisone (Systemic only) Loteprednol (Topical only) ( No IOP Rise) Flouromethalone (Topical only) ( No IOP Rise)
Intra lesional in hemangioma and chalazion Iv in optic neurirtis Oral in dysthyroid ophthalmopathy. Corneal transplant Intravitreal in CRVO Topical postoperative, uveitis, corneal transplant Intracameral Per-op in children
The patient with orbital cellulitis should be promptly hospitalized for treatment. Hospitalization should be continued until the patient is afebrile and is clearly improved clinically. Symptomatic; antipyretic, NSAIDS Antimicrobials ; ◦ Ceftazidime 1 g tds, I/M ◦ Metronidazole 500mg tds, PO ◦ Vancomycin in case of allergy to the above mentioned Surgical intervention in case of local abscess or unresponsive cases Consultation with ENT specialist, neurosurgeon & paediatrician if required
Specifically identified pathogens identified on cultures. Intravenous antibiotic therapy should be continued for 1-2 weeks and then followed by oral antibiotics for an additional 2-3 weeks. Fungal infection requires intravenous antifungal therapy along with surgical debridement.
Surgical drainage of an orbital abscess is indicated if any of the following occurs: A decrease in vision occurs. An afferent pupillary defect develops. Proptosis progresses despite appropriate antibiotic therapy. The size of the abscess does not reduce on CT scan within 48-72 hours after appropriate antibiotics have been administered. If brain abscesses develop and do not respond to antibiotic therapy, craniotomy is indicated.
SAFE strategy developed by WHO for trachoma: Surgery: ◦ To prevent blindness & limits progression of corneal scarring. ◦ Can improve vision. Antibiotics: ◦ Azithromycin—1 G single dose (adults). ◦ Children: 20mg/kg single dose
Erythromycin 250 mg QID for 4 weeks. (children 125mg/kg). Tetracycline 250 mg QID for 4 weeks. Topical tetracycline 1% 0.5 inch ribbon BD for 6 weeks. Facial cleanliness: ◦ Reduces risk & severity of trachoma. Environmental change: ◦ Improved water supply & household sanitation. ◦ Personal & community hygiene. ◦ Adequate housing & water & sewage system.
Topical Tetracycline. Oral Erythromycin 25mg/kg body weight 12 hourly for 14 days. Caution: Examine mother & father for chlamydial urethritis/ cervicitis and treat.
To prevent further damage to the eye by lowering IOP & to ultimately prevent blindness
Plasma Expanders Urea Mannitol 20% IV solution. Dose: 1-2g/kg or 5 ml/kg body weight. Up-to 60 drops/min over 20-30 min. Peak of action: within 30 min. Duration of action: up-to 6 hrs. Diuretics IV Acetazolimide
50% solution. Oral agent with a sweet & sickly taste. Pure lemon should be added to avoid nausea. Dose:1-2g/kg or 2-4ml/kg body weight. Peak of action: Within 1 hr. Duration of action: Upto 3 hrs. Metabolized to glucose in the body.
Oral agent with a minty taste. Dose: Same as for glycerol. Metabolically inert & can be given to diabetics without insulin cover.
Mechanism Of Action: 1- POAG: Stimulation of longitudinal muscle of ciliary body---pull on scleral spur---widening of trabecular spaces---lowering of IOP. 2- PACG: Opening the angle by pulling the peripheral iris away from the trabeculum.
Indications: POAG. Acute ACG. Many secondary glaucomas. Good additive effect with beta blockers. Response: Blue eyes: Max. response. Dark eyes: Relatively low response.
Pilocarpine(1%,2%,3%,4%): One-half inch ribon at bed time. Induced myopia & miosis lasts only during sleep. Corneal haze in 20%, rarely affects VA. Pilocarpine sustained-release (Ocusert Pilo-20 & Pilo-40): Polymer containing adsorbed pilocarpine. Inserted in upper fornix---7 days. Pilo-20: Equivalent to pilocarpine 1% drops. Pilo-40: Equivalent to pilcarpine 2-4% drops.
Parasympathomimetic muscarinic agonist, also a weak chloinesterase inhibitor. Onset of action: Within 40 min. Duration: 12 hrs. Dose: 8 hourly. Good alternative to pilocarpine in resistant cases. 0.01% intraocular solution for miosis during surgery.
Epinephrine 0.5, 1%, 2% Mechanism Of Action: Increases both trabecular & uveoscleral outflow via beta agonist activity mediated by cyclic AMP. Tripple response: Conj. decongestion, slight mydriasis & reduction of IOP. Onset of action: Within 1 hr. Duration of action:12 - 24 hr. Indications: POAG, ocular hypertension.
Dipivefrin (0.1%)—(Propine) Prodrug: Converted to adrenaline after absorption. Penetration 17 times greater than adrenaline. Duration of action same. IOP lowering effect is comparable with 1% adrenaline. Fewer side effects.
Twice daily dose. Wash out period: 3.3 wks. Peak effect at 2 hrs. Duration of action 12 hrs. Comparable to Timolol. Nonresponder: Less than 10%. No tachyphylaxis. Good additivity to beta blockers, CAIs & miotics. No vasoconstrictive effect in retinal tissues.
Prophylaxis of post-laser IOP spike. Property of neuroprotection in animal models. SIDE EFFECTS: Ocular: Follicular conj., contact dermatitis, ocular irritation & hyperemia. Systemic: Bradycardia, hypotension, apnea in neonates.
Pharmacokinetics: Highly selective alpha-2 agonist. Easy penetration to cornea. Lower access to CNS: Less lipophilic, rapid metabolism, short plasma half life. Reduce allergic reaction: Not produce hapten. Mechanism Of Action: Reduce IOP by initial decreasing aqueous production followed by increase in uveoscleral flow.
Mechanism Of Action: Decrease aqueous secretion with little effect on episcleral venous pressure. 10% unresponsive. First choice medication for POAG. Non-selective or cardioselective. Contralateral effect.
0.25% and 0.50% BD. Timolol LA 0.25% and 0.50%. Digital pressure over eyes after medication (3minutes) to reduce systemic absorption.
0.5% BD. Cardio-selective. Ocular hypotension < Timolol & Levobunolol & similar to Carteolol. IOP reduction 6 mm Hg. Less effective than Timolol in post-cataract surgery increase in IOP. Increases retinal blood flow. Superior visual fields protection.
Non selective. Onset of action: Within 1 hr. Peak of action: 2-6 hr. Duration: 24 hr. Dose: Usually OD. Potent as Timolol.
Non-selective. More selective action on the eye than cardiopulmonary system. (less bradycardia than Timolol). Efficacy similar to Timolol. Metipronolol (0.1%, 0.3%) Non-selective. Similar properties to Timolol.