2. The iris muscles Iris, ciliary body, sphincter and ciliary
muscles are innervated by CN III
3. Agonists/Antagonists
4. Pharmocological Mydriasis Mydro=to widen
5. CLINICAL PHARMACOLOGY This anticholinergic preparation
blocks the responses of the sphincter muscle of the iris and the
ciliary muscle to cholinergic stimulation, dilating the pupil
(mydriasis).The stronger preparation (1%) also paralyzes
accommodation. This preparation acts in 15-30 minutes and the
duration of activity is approximately 3-8 hours. Complete recovery
from mydriasis in some individuals may require 24 hours.The weaker
strength may be useful in producing mydriasis with only slight
cycloplegia. Heavily pigmented irides may require more doses than
lightly pigmented irides.
6. Rx for Pharmacological Mydriasis
7. Pharmacological Mydriasis
8. Phenylephrine
9. Clinical Indications for Pharmocological mydriasis
10. Phenylephrine 1% or Cocaine
11. Cycloplegics
12. Pharmacological Cycloplegia
13. CLINICAL PHARMACOLOGY This anticholinergic preparation
blocks the responses of the sphincter muscle of the iris and the
accommodative muscle of the ciliary body to cholinergic
stimulation, producing pupillary dilation (mydriasis) and paralysis
of accommodation (cycloplegia). It acts rapidly, but has a shorter
duration than atropine. Maximal cycloplegia occurs within 25 to 75
minutes after instillation. Complete recovery of accommodation
usually takes 6 to 24 hours. Complete recovery from mydriasis in
some individuals may require several days. Heavily pigmented irides
may require more doses than lightly pigmented irides.
