Dr Ajai Agrawal Additional Professor Department of Ophthalmology AIIMS Rishikesh Learning Objectives At the end of this class students shall have a basic understanding of ID: 1048103
Download Presentation The PPT/PDF document "Ocular Pharmacology -II" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. Ocular Pharmacology -II Dr. Ajai AgrawalAdditional ProfessorDepartment of OphthalmologyA.I.I.M.S., Rishikesh
2. Learning Objectives At the end of this class students shall have a basic understanding of :Therapeutic agents for glaucomaAnti-inflammatory agentsTear substitutesDrugs and biological agents used in Ophthalmic surgeryOcular toxicology
3. Overview
4. Agents used for treatment of Open angle Glaucoma Prostaglandin analoguesBeta receptor antagonistsAlpha receptor agonistsCarbonic anhydrase inhibitors
5. Prostaglandin AnalogsFirst- line medical therapy for GlaucomaPGF2α analogs - Good efficacy Once daily application Absence of systemic side effects1.Latanoprost 2. Travoprost 3.Bimatoprost Facilitate aqueous outflow through uveoscleral outflow pathway
6. Prostaglandin Analogs Side effects Ocular irritation & pain Blurring of vision Increased iris pigmentation Macular edema
7. β Adrenergic blockersNonselective β blockers – Timolol maleate - Levobunolol - Metipranolol - Carteolol β -1 antagonist - Betaxolol
8. Mechanism of Action of β BlockersLower IOP by reducing aqueous formation-- Down regulation of adenylylcyclase due to β2 receptor blockade in ciliary epithelium-- Reduction in ocular blood flow
9. Adverse Effects of Ocular β Adrenergic blockers OcularStinging, redness & dryness of eyeCorneal hypoesthesiaAllergic blepharoconjunctivitisBlurred vision SystemicBronchospasm in asthmatics & COPD patientsBradycardia & accentuation of Heart block Minimization of systemic adverse effects
10. Alpha Adrenergic agonistsBrimonidine (Alpha-2 agonist)(0.1%,0.2%)Usually used as an add on agentMainly reduces aqueous productionAlso increases uveoscleral outflowTo be used cautiously in children and elderly as it may cause fatigue and drowsiness.
11. Carbonic anhydrase Inhibitors (CAI)Systemic -AcetazolamideTopical CAI – Dorzolamide , BrinzolamideInhibits carbonic anhydrase (isoenzyme II) on ciliary body epithelium → Reduces formation of bicarbonate ions → Reduces fluid transport → Reduces aqueous formation → Decrease IOPUse – Only as add on drug to topical β blockers or PG analogsSystemic CAI – Final medication option before resorting to laser or incisional surgical treatment
12. Carbonic anhydrase Inhibitors (CAI) Side effectsParesthesiaFrequent urinationGI disturbancesHypokalemia
13. Topical MioticsOnly of historical importance in open angle glaucoma- Ciliary muscle contraction - Increase drainage through trabecular meshworkDrug----Pilocarpine 1,2,4%.Less useful drug – Numerous side effects & three to four times a day dosing
14. Stepped Medical Approach to Treatment of Open Angle Glaucoma
15. Angle closure GlaucomaHypertonic Mannitol ( 20%) IV infusion 1.5 -2 g/kg 2. Acetazolamide - 0.5 g oral 3. Miotic - Pilocarpine (1-4%) 4. Timolol 0.5 % - instilled 12 hourly.Definitive treatment – Surgical/ Laser iridotomy
16.
17. stimulusPhospholipase A2LipoxygenasesLeukotrienesSteroidsNSAIDS
18. CorticosteroidsCLASSIFICATION Short acting Hydrocortisone, Cortisone, PrednisoloneIntermediate acting Triamcinolone, FluprednisoloneLong acting Dexamethasone ,Betamethasone
19. Therapeutic Uses of Topical steroidsSignificant ocular allergyAnterior uveitisPostoperative inflammation following refractive, corneal & intraocular surgeryTo reduce potential scarring of surgical site (After Glaucoma filtering surgery )NEVER GIVE STEROIDS IF YOU ARE SUSPECTING ACTIVE INFECTION
20. Steroids in ocular conditions…… Systemic steroids & by sub-Tenon’s capsule injection – Posterior UveitisIntravitreal injection – -- Age-related Macular degeneration (ARMD) -- Diabetic Retinopathy -- Cystoid Macular Edema (CME)Parenteral steroids followed by tapering oral doses – Optic Neuritis
21. ALLERGIC CONJUNCTIVITIS
22. SCLERITIS
23. ANTERIOR UVEITIS
24. OPTIC NEURITIS
25. Toxicity of SteroidsPosterior subcapsular cataractsSecondary infectionsSecondary open-angle glaucoma4. Delayed wound healing“ Soft steroids (e.g., Loteprednol ) reduce the risk of elevated IOP ”
26. SYSTEMIC side effects of steroids Peptic ulcer Hypertension Increased blood sugar Osteoporosis Mental changes Activation of tuberculosis and other infections
27. Topical NSAIDs & their Ocular UsesSr. No. Topical NSAID Ocular Use1FlurbiprofenTo counter unwanted intraoperative miosis during cataract surgery2Ketorolac-Seasonal allergic conjunctivitis-Cystoid Macular Edema (CME ) occuring after cataract surgery3Diclofenac-Postoperative inflammation-Cystoid Macular Edema (CME ) occuring after cataract surgery4BromfenacPostoperative pain & inflammation after cataract surgery5NepafenacPostoperative pain & inflammation after cataract surgery
28. Tear SubstitutesHypotonic or isotonic solutions – Eg: Carboxymethylcellulose Polyvinyl alcohol Polyethylene and propylene glycolIndications Ocular irritation in various diseases Dry eye disease
29. Therapeutic Uses of Tear SubstitutesOcular diseases – Allergic conjunctivitis - Blepharitis - Corneal dystrophies - Chemical BurnsSystemic diseases – Sjogren’s syndrome - Rheumatoid arthritis - Vitamin A deficiency - Stevens-Johnson syndrome
30. Immunosuppressive & Antimitotic AgentsAgents commonly used – 1. 5-fluorouracil 2. Mitomycin C Used In Glaucoma surgery, to improve success of filtration surgery by limiting postoperative wound-healing process.In corneal surgery, to reduce risk of scarring after excision of pterygium
31. Immunomodulatory AgentTopical Cyclosporine – Approved for the treatment of chronic dry eye associated with inflammation -Decreases inflammatory markers in lacrimal gland & increases tear production
32. Ocular diagnostic drugsFluorescein dyeAvailable as drops or strips Uses: To stain corneal abrasions applanation tonometry detecting wound leak fluorescein angiographyCaution:Stains soft contact lensFluorescein drops can be contaminated by Pseudomonas sp.
33. Ocular diagnostic drugsRose bengal stainStains devitalized epitheliumUses: severe dry eye, herpetic keratitis
34. Anaesthetics In Ophthalmic Procedures Proparacaine & tetracaine drops – Uses – Tonometry Gonioscopy Removal of foreign bodies, sutures on conjunctiva and cornea Adverse effects: toxic to corneal epithelium allergic reaction (rarely)
35. Drugs & Biological Agents Used in Ophthalmic Surgery
36. Sr. No.Drugs & Biological AgentsUse in Ophthalmic Surgery1Povidone iodine (5% solution)To prepare periocular skin & to irrigate cornea, conjunctiva & palpebral fornices2Viscoelastic substances(chondroitin sulphate, hydroxypropylmethylcellulose)Maintain spaces & protects surfaces during anterior segment surgery3Ophthalmic Glue-Cyanoacrylate tissue adhesiveFibrinogen GlueCorneal ulcerations & PerforationsTo secure conjunctiva & corneal grafts.4Anterior Segment GasesSulfur Hexafluoride (SF6)PerfluoropropaneReattachment of Descemet’s membrane to stroma of Cornea5Vitreous SubstitutesReattachment of retina following Vitrectomy.
37. Botulinum Toxin Type A
38. Ophthalmic Effects of Selected Vitamin Deficiencies & Zinc DeficiencyDeficiencyEffects in Anterior SegmentEffects in Posterior SegmentVitamin AConjunctiva(Bitot’s spot, xerosis)Cornea (Keratomalacia , Punctate keratopathy)Retina(Nyctalopia)Retinal pigment epithelium (hypopigmentation)Vitamin B1 ----Optic nerve (Visual field defects)Vitamin B6Cornea(Neovascularization)Retina (Atrophy)Vitamin B12 ------Optic nerve (Visual field defects)Vitamin CLens (? Cataract formation) -------
39. Ophthalmic Effects of Selected Vitamin Deficiencies & Zinc DeficiencyDeficiencyEffects in Anterior SegmentEffects in Posterior SegmentVitamin E --------Retina & retinal pigment epithelium (? Macular degeneration)Folic acid ------- Vein occlusionVitamin KConjunctiva (Hemorrhage)Retina (Hemorrhage)Zinc ------Retina & retinal pigment epithelium (? Macular degeneration)
40. Ocular Toxicology
41. ToxicologyAll opthalmic medications – Potentially absorbed into systemic circulation – Undesirable systemic side effectsEg. Timolol (single eye drop) - Death Local toxic effects – Hypersensitivity reactions -- Preservatives in eye drops & contact lens solutions –Benzalkonium chloride – Punctate KeratopathyThimerosal – Hypersensitivity reactions
42. Complications of topical administrationMechanical injury from the bottle e.g. corneal abrasionPigmentation: epinephrine-adrenochromeOcular damage: e.g. topical anesthetics, benzylkoniumHypersensitivity: e.g. atropine, neomycin, gentamicinSystemic effect: topical phenylephrine can increase BP
43. Amiodarone A drug for treatment of cardiac arrhythmia Causes optic neuropathy (mild decreased vision, visual field defects, bilateral optic disc swelling)Also causes corneal vortex keratopathy (corneal verticillata) which is whorl-shaped pigmented deposits in the corneal epithelium
44. Digitalis A drug for treating cardiac failure Causes chromatopsia (objects appear yellow) with overdose
45. Chloroquines E.g. chloroquine, hydroxychloroquineUsed in malaria, rheumatoid arthritis, SLECause vortex keratopathy (corneal verticillata) which is usually asymptomatic but can present with glare and photophobiaAlso cause retinopathy (bull’s eye maculopathy)
46. Chorpromazine An antipsychotic drugCauses corneal punctate epithelial opacities, lens surface opacitiesRarely symptomaticReversible with drug discontinuation
47. Thioridazine A psychiatric drugCauses a pigmentary retinopathy after high dosage
48. Diphenylhydantoin An epilepsy drugCauses dosage-related cerebellar-vestibular effects: Horizontal nystagmus in lateral gazeDiplopia, ophthalmoplegiaVertigo, ataxia Reversible with discontinuation of the drug
49. Topiramate A drug for epilepsyCauses acute angle-closure glaucoma (acute eye pain, redness, blurred vision, haloes).Treatment is by cycloplegia and topical steroids (rather than iridectomy) with the discontinuation of the drug
50. HMG-CoA reductase inhibitors (statins)Cholesterol lowering agentsE.g. pravastatin, lovastatin, simvastatin, fluvastatin, atorvastatin, rosuvastatinCan cause cataract in high dosages specially if used with erythromycin
51. Ethambutol An anti-tubercular drugCauses a dose-related optic neuropathyUsually reversible but occasionally permanent visual damage might occur
52. Systemic Agents with Ocular Side EffectsSr. No. Name of Drug Ocular Side Effect1. TopiramateAngle Closure Glaucoma2.Hydroxychloroquine/ChloroquineChloroquine amblyopia ( Bull’s Eye Maculopathy )3.TamoxifenCrystalline Maculopathy4.VigabatrinProgressive & Permanent bilateral concentric visual field constriction5.Sildenafil/Vardenafil/tadalafilNonarteritic Ischemic Optic Neuropathy (NAION )6.Ethambutol, Chloramphenicol , RifampinToxic Optic Neuropathy (Progressive bilateral central scotomas & vision loss )7.Ocular SteroidsElevated IOP & Glaucoma8.SteroidsCataract
53. Systemic Agents with Ocular Side Effects……..Sr.No. Name of DrugOcular Side Effect9.Rifabutin + Clarithromycin / Fluconazole Iridocyclitis & Hypopyon10.IsotretinoinDry eye & meibomian gland dysfunction11.AmiodaroneDrug deposits in cornea ( Cornea verticillata )12.Chlorpromazine & ThioridazineBrown pigmentary deposits in the cornea13.GoldChrysiasis ( gold deposits in cornea & conjunctiva )14.TetracyclinesYellow discoloration of light-exposed conjunctiva
54. Visual field constriction Cataract
55. Thank you