1. PHARMACOLOGY OF THE EYE
Prepared By:
Dr./ Rehab Lashine
Pharmacology Department

2. Physiological Anatomy of the Eye

3. THE ANT.CHAMBER OF THE EYE

4. The Ciliary Body

5. The Pupil

6. Pupillary Muscles

7. Mydriasis

8. Miosis

9. Effect of Miosis and Mydriasis on Acquous Humor Drainage

11. Accomodation

12. Autonomic Nerve supply of the Eye
Parasympathetic:
1- Bl.Vs. …Conjuctival VD ( Oculomotor)
2- Ciliary mm.. (Accomodation) (Oculomotor)
3- Sphincter pupillae(Miosis) (Oculomotor)
4- Increased lacrimation…..7th vranial n.
(N.B.: Stim. Of the nic. Rec. causes twitches of eye lid mm.)

13. Sympathetic 1- Bl.Vs.( Conjunctival VC)………α1
2- Dilator Pupillae ( Mydriasis)…….. α1
3- Levator palpebrae & Muller’s m.(Exophthalmus & widening of the palpebral fissure)…..
4- Ciliary mm (relaxation)……. β2
5- Lacrimal glands (lacrimation)……… α1
6- α & β rec. in the Bl.vs. of the ciliary processes….help in regulation of aqueous humour formation

14. Light Reflex

16. Corneal Reflex

17. Drugs Acting on the Eye I- Drugs affecting the size of the pupil:
Miotics
Mydriatics
II- Drugs Affecting Accomodation….Cycloplegics
III- Drugs affecting the IOP (intraocular pressure)
IV- Local Anesthetics
V- Antiallergic agents
VI- TTT of Eye Infection

18. Miotics M3 rec.: Parasympathomimetics
α1 blockers: Sympatholytics(e.g.Phenoxybenzamine)
Central : Morphine ( ↑oculomotor nucleus)
USES:
-Glaucoma
-Counteract action of mydriasis
- To break adhesions

19. Mydriatics
Active:
- Sympathomimetics….(Mydriasis without Cycloplegia or loss of light reflex)
- Local anesthetics…..(Cocaine) (Mydriasis without Cycloplegia or loss of light reflex ).
Passive:
- Anticholinergics……(Mydriasis with Cycloplegia & loss of light reflex) except Eucatropine (doesn’t cause cycloplegia).
Ganglion Blockers …...(Mydriasis with Cycloplegia )
Central
USES:
Fundus Exam, Therapy of acute Iritis, Breaking Adhesions

20. Drugs Affecting Accomodation
Drugs causing Accomodation to near objects:
- stim. of ciliary mm: Parasympathomimetics
Cycloplegics: drugs causing paralysis of ciliary mm…..loss of accomodation…fixation of vision for far vision: Parasympatholytics (EXCEPT EUCATROPINE)

21. N.B.:
Sympathomimetic mydriatics are safely used in adults > 40 years in whom Atropine have the risk of causing dangerous rise in IOP.
Therapeutic uses of Cycloplegic drugs:
1- Ttt of Iridicyclitis
2- Ttt of choroiditis
3- Measurement of refractive errors

22. Drug Therapy of Primary Open Angle (chronic simple) Glaucoma
A) Miotics: They act mainly by↑ the acqueous outflow.
1- Direct : pilocarpine.
2- Indirect: choline esterase inhibitors
B) Sympathomimetics: ↓ acq.humour production, & ↑ outflow
C) Β-adrenoceptor blocking agents: ↓ acq.humour production…….Timolol, befunolol
D) Oral Agents: Carbonic Anhydrase inhibitors. ↓ acq.humour production…..Acetazolamide

23. Drug Therapy of acute angle closed (congestive) glaucoma
Dehydrating agents: IV infusion Of Hypertonic solution ( Mannitol, Glycerol)
Oral Acetazolamide
Topical miotics: e.g.: pilocarpine
Analgesics: pethidine or morphine (for pain)

24. Drug used in treating inflammatory and allergic eye conditions
1- Conjunctivitis: can be ttted by:
A- Penicillin G, chloramphenicol ( Acute purulent conj.)
B- Sulphacetamide (eye drops)..for trachoma
C- Tetracycline ….for chronic follicular conjunctivitis
D- Vidarabine, or Acyclovir for Herpes simplex keratitis
E- Topical steroids for chronis puppillary conj.

25. Drug used in treating inflammatory and allergic eye conditions( Cont.)
2- Glucocorticoids: to suppress inf., and allergy
3- Topical Antihistaminics: (eye drops), in allergies
4- Sodium cromoglycate: ( for ttt. Of spring catarrh, vernal keratoconjunctivitis)
5- Astringents : Zinc Sulphate ( angular conj.)

26. Harmful drugs for the Eye
1- Drugs that ↑ IOP:
A- Mydriatic cycloplegics, tricyclic antidepressants
B- Chronic steroid use
2- Cataractogenic drugs: steroids, phenothiazines, heavy metals…
3- Drug-induced retionopathies: ethanol, methano, indomethacin,steroids
4- Drugs causing corneal deposits: Amiodarone, chloroquine…
5- Oculomucocutaneous syndrome ( Conj. Fibrosis, corneal opacities,and dimnished tear secretion) e practolol
6- O2 : 40 % for prolonged periods in premature infants causes Retrolental fiboplasia

27. Experiment