Mydriasis

Dr. Ayush PandeyMBBS,PG Diploma

January 03, 2019

March 06, 2020

Mydriasis
Mydriasis

What is mydriasis?

As a part of light reflex in the eyes, pupils dilate or widen in the dark to allow more light in and constrict when it is bright. Mydriasis is a condition where there is unusual dilation of pupils to a size greater than six millimetres. The pupils fail to constrict when stimulated with light.

What are its main signs and symptoms?

The main signs and symptoms of mydriasis are:

  • The characteristic sign is that the size of the pupils does not change in response to light. They remain larger than normal.
  • Blurred vision
  • Feeling of constriction around the eyes and forehead
  • Headache
  • Dizziness
  • Irritation in the eyes
  • Difficult in eye movement
  • Drooping eyelids

What are the main causes?

The main causes of mydriasis are:

  • Trauma
  • Drugs like anti-histamines and muscle relaxants
  • Drug abuse and addiction
  • Injury to pupillary nerve fibres
  • Closed-angle glaucoma
  • Plants such as Jimson weed, angel’s trumpet and members of the belladonna family
  • History of multiple headaches/migraines
  • Stress
  • Increase in oxytocin level
  • Damage to cranial nerves, brain injury or increased pressure to brain
  • Infection or injury to the eye
  • Diabetes

How is it diagnosed and treated?

Diagnosis:

  • Medical and medication history is determined to identify the cause.
  • Signs such as frequent widening of pupils in bright environments are noted.
  • Tests such as visual acuity and ocular motility are performed to evaluate the function of the eye muscles.
  • 1% pilocarpine drops are administered, which normally causes constriction of the pupils after 45 minutes of instillation.

Prevention:

  • Avoid direct sunlight
  • Use sunglasses in bright environments
  • Avoid reading the text too close to the eyes

Treatment:

  • The treatment approach is to protect the functionality of the eyes. The treatment is determined based on the underlying cause.
  • Surgery may be required to repair damage to nerves or eye structures.



References

  1. Spector RH. The Pupils. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 58.
  2. American Academy of Ophthalmology [Internet] California, United States; Pupil Efferent Defects.
  3. Wilhelm H,Wilhelm B,Schiefer U. Mydriasis caused by plant contact. Fortschr Ophthalmol. 1991;88(5):588-91. PMID: 1757054
  4. National Institutes of Health; [Internet]. U.S. National Library of Medicine. Lidocaine Usage for Pupil Dilatation (Mydriasis).
  5. National Institutes of Health; [Internet]. U.S. National Library of Medicine. Optimal Method for Mydriasis in Cataract Surgery.

Medicines for Mydriasis

Medicines listed below are available for Mydriasis. Please note that you should not take any medicines without doctor consultation. Taking any medicine without doctor's consultation can cause serious problems.