Lecture 13 Glaucoma Therapeutics Paterson Types of Glaucoma Aqueous outflow: Open-angle: optic neuropathy characterized by Conventional pathway: trabecular visual field loss; usually associated with elevated IOP Overflow pathway: uveoscleral o Chronic, often asymptomatic Narrow-or closed-angle: closure of the angle Who to treat: between the iris and cornea, obstructing the outflow Glaucoma (elevated or normal IOP) of aqueous humor Ocular hypertension (IOP > 21 mmHg) & o Painful red eye, can lead to permanent high risk of progression blindness w/in 24 h o Higher baseline IOP, clinical findings, increasing age, African descent, family Goals of therapy: history, Type 2 diabetes mellitus Preserve visual function by slowing or halting progression of disease Target IOP o Lower IOP (only clinically established method of Pressure likely to stop further damage to treating glaucoma) optic nerve o Preserve structure & function of optic nerve Not fixed and should be regularly re- Maintain or enhance health-related quality of life evaluated o Minimize side effects of treatment and its Depends on pre-treatment IOP, degree of impact on patient’s vision and general health optic nerve damage, visual field loss, age, other factors Initial treatment Intensification of therapy: Early or moderate open-angle glaucoma Combination of topical medications o Prostaglandin analogue (most efficacious, Laser therapy: trabeculoplasty (increases AH well-tolerated, once daily) outflow) o Alternatives: β blockers, α agonists Surgery: alternative route for outflow Advances open-angle glaucoma: laser or surgery o Possible scar tissue formation with prostaglandin analogue in interim o Mechanical shunts also used Preservatives, contact lenses Alternative interventions: not been shown to Preservatives alter outcomes o Benzalkonium chloride: most common; 6% allergic Aerobic exercises can lower IOP modestly o Travoprost: ionic buffer preservative Canadian Opthalmological Society does not o Brimonidine: purite preservative support the use of marijuana for treatment o Some single dose, preservative-free forms of glaucoma (short duration of action & Need to wait at least 15 min after drops with BAK undesirable psychotropic and other before contacts lens insertion systemic side effects) Monitoring Proper eye drop technique Efficacy: Shake well (roll in hands for 30 secs) o IOP/visual field/optic nerve head Wash hands . Early: every 12 months One drop or ¼ - ½ inch ointment strip inside lower eyelid . Moderate: every 6 months . Severe: every 4 months Close eyes for 1 min (up to 5) or punctal occlusion o Adherence (education of pts) 5 min b/w drops, 10 min before oint . Minimize # of medications Order: solution first, then susp/gel then ointment Safety: adverse effects; disease-drug interactions Lecture 13 Glaucoma Therapeutics Paterson Medications to avoid Open angle: corticosteroids (all Narrow-angle: formulations) Anticholinergic effects can cause dilation of pupil (blocks Reduced outflow of AH movement of AH) Alternative to ophthalmic CST o Antidepressants; 1st gen antihistamines; antispasmodics; is NSAID cyclobenzaprine; decongestants; H2 blockers; inhaled Use lowest potency for anticholinergics shortest time Lens swelling due to allergic reaction (sulfonamides) Monitor IOP with use > 10 days Increased risk: female, far-sighted, family history, age PG > Beta blockers > alpha agonists > B1 blocker Topical medications Med class MOA Ex SEs Contraindications Prostaglandin Increased Bimatoprost (also Iris darkens Macular edema analogues uveoscleral increase Conjunctival hyperemia History of herpetic keratitis outflow trabecular Burning, stinging, foreign- Active uveitis OD outflow) body sensation Pregnancy Eyelash change (reversible) ↓IOP 25-33% Latonprost Migraine Travoprost Flu-like sx Beta Inhibit Selective B1: Allergic conjunctivitis Asthma antagonists formation of betaxolol Bronchospasm Sinus bradycardia aqueous Non-selective: Bradycardia Heart block/ failure OD – BID humor timolol; Hypotension Hypotension levobunolol Mask sx of hypoglycemia Depression ↓IOP 20-25% Caution in preg NASOLACRIMAL OCCLUSION Timolol in lactation reduces SEs by 50% Alpha-2 Decreased Aproclonidine Allergic conjunctivitis With MAOIs agonists production Brimonidine Dry mouth & nose Caution in pregnancy & increased Hypotension BID – TID outflow Headache (brimonidine Fatigue ↓IOP 20-25% does both) Para- Increased Pilocarpine Bronchospasm Neovascular, uveitic or sympatho- AH outflow Brow ache malignant glaucoma mimetics (stimulate M Intestinal cramps Caution in pregnancy (cholinergics) receptors) Miosis Myopia w/ spasm TID – QID Retinal detachment ↓IOP 20-25% Carbonic Inhibit Brinzolamode Allergic Kidney stones anhydrase enzyme Dorzolamide dermatitis/conjunctivitis Aplastic anemia inhibitors involved in Burning Sickle cell anemia formation of Corneal edema Thrombocytopenia BID – TID AH Metallic taste Sulfa allergy reduce Oral agents associated w/ ↓IOP 15-20% production teratogenicity .