Mydriatics are drugs used for pupil dilation, while cycloplegics also paralyze the sphincter muscle, aiding in detailed fundus examinations and cycloplegic refraction. Common examples include atropine, tropicamide, and cyclopentolate, which can cause side effects such as photophobia and blurring of vision. Atropine has specific indications and contraindications, including its use in inflammatory conditions and caution in acute congestive glaucoma.

1. Mydriatics & Cycloplegics :
Defination, Mechanism of action,
indications,contraindications, side
effects
SCEH, Lahan.

2. Defination
• Mydriatics are the group of drugs that are used for dilatation of
pupil. :: detail fundus examination.
• Cycloplegics are drugs that are used for dilatation as well as
for paralysing sphincter muscle. Detailed fundus examination,
cycloplegic refraction.

3. Classification
• Natural alkaloids :Atropine, Hyoscine (Scopolamine).
• Semi synthetic : Homatropine.
• Synthetic :
a) Mydriatics : Cyclopentolate, Tropicamide.
b) Antisecretory- antispasmodics : Dicyclomine
c) Antiparkinsonism : Dicyclomine

4. ATROPINE
• Mechanism of action : block actions of Acetylcholine on
autonomic effectors & in the CNS via muscarinic receptor.
• Topical instillation causes
1. Mydriasis
2. Abolition of light reflex
3. Cycloplegics (lasts for 7-10 days).
4. Mild anaesthetic action on the cornea.

5. ATROPINE
• Has effect in other parts of our body : CNS, CVS, GI, Smooth
muscle, glands.

6. ATROPINE : Indications
• Mydriasis, detailed fundus examination and cycloplegic
refraction.
• Inflammatory condition : Uveitis, corneal ulcer,
endophthalmitis. Breaks synechiae , relieves ciliary spasm
• Used in glaucoma but only in neovascular & malignant
glaucoma.

7. ATROPINE : Side effects
• Photophobia.
• Blurring of vision.

8. ATROPINE : Contraindication
• Acute congestive Glaucoma .

9. Mydriatics
• Tropicamide : potent and quickest of all mydriatics drugs (lasts
for 6 hours).
• Tropicamide with phenylephrine : faster and more potent.
• Cyclopentolate : potent drug and works for 2-3 days after
instillation.

10. Indications
• Mydriasis, detailed fundus examination and cycloplegic
refraction.
• Inflammatory condition : Uveitis, corneal ulcer,
endophthalmitis. Breaks synechiae , relieves ciliary spasm
• Used in glaucoma but only in neovascular & malignant
glaucoma.

11. Side effects
• Photophobia.
• Blurring of vision.

12. Contraindication
• Acute congestive Glaucoma

13. Thank you