Pharmacotherapyy of Open angle glaucoma - kGmu

Glaucoma

1. Pharmacotherapy of Open Angle Glaucoma BY- Dr. Ajay Kumar A.N. Junior Resident Dept. of Pharmacology & Therapeutics King George’s Medical University Lucknow

2. Contents Introduction Anatomy Pathophysiology Treatment: Medical References

3. Introduction Glaucoma is a worldwide leading cause of irreversible vision loss. Characterized by : Progressive optic neuropathies Degeneration of retinal ganglion cells

4. Open Angle Glucoma It is probably a genetically predisposed degenerative disease affecting patency of the trabecular meshwork. Normal IOP: 12-21 mmHg The i.o.t. rises insidiously and progressively IOP is not a mandatory feature of glaucoma eg : Normal tension glaucoma, Ocular Hypertension

5. Iridocorneal angle: Anatomy

6. Aqueous humor: Physiology Scleral veinous plexus episcleral vein Trabecular meshwork Trabecular outflow Uveoscleral outflow Ciliary vessels Ciliary epithelium

7. Pharmacotherapy Ocular hypotensive drugs are used as definitive treatment in majority of cases. Goals: Achieve a target intraocular pressure

8. Classification: Drugs Tripathi KD, editor. Essentials of Medical Pharmacology . 9th ed. New Delhi: Jaypee Brothers Medical Publishers; 2019. p. 166-170

9. Tripathi KD, editor. Essentials of Medical Pharmacology . 9th ed. New Delhi: Jaypee Brothers Medical Publishers; 2019. p. 166-170

10. 1. β Adrenergic blockers Lower intraocular tension by reducing aqueous formation -Downregulation of Adenylyl Cyclase in ciliary epithelium -Secondary effect due to reduction in ocular blood flow. Eg . Timolol(0.25%), Betaxolol etc.

11. 2. α Adrenergic agonists Decreases aqueous production Act on α1 α2 E.g. Apraclonidine(0.5%), Dipivefrine, Brimonidine Blood vessel ciliary body Ciliary epithelial cell Vasoconstriction Decrease the movement of water from stroma to posterior chamber

12. 3. Prostaglandin analogues Low concentration of PGF2a (no ocular inflammation) Acts by : e.g . Latanoprost ( 0.005%), Travoprost, Bimatoprost etc.

13. 4. Carbonic anhydrase inhibitors Reduces aqueous formation by: limiting the generation of bicarbonate ions in the ciliary epithelium. e.g . Acetazolamide, Dorzolamide etc. 125mg, Oral 2%, Topical

14. 5. Miotics In open angle glaucoma lowers i.o.t. Increasing cilliary muscle tone thereby improving patency of trabeculae E.g . Pilocarpine(1-4%).

15. Summary Open angle glaucoma is a most common type of glaucoma Normal IOP: 12-21 mmHg Pharmacotherapy: β Adrenergic blockers α Adrenergic agonists Prostaglandin analogues Carbonic anhydrase inhibitors Miotics

16. References Tripathi KD, editor. Essentials of Medical Pharmacology . 9th ed. New Delhi: Jaypee Brothers Medical Publishers; 2019. p. 182-186 Brunton LL, Knollmann BC, editors. Goodman & Gilman’s the pharmacological basis of therapeutics . 14th edition. New York: McGraw Hill; 2023 .p.270-274 Weinreb RN, Aung T, Medeiros FA. The Pathophysiology and Treatment of Glaucoma : A Review. JAMA. 2014 May 14;311(18):1901.

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