MEDICATION DEVICES USED IN OPHTHALMOLOGY
- Contact Lenses
- Corneal Shields
- Cotton Pledgets
- Filter Paper Strips
- Artificial Tear Inserts
- Membrane Bound Inserts
Contact Lenses
Therapeutic soft contact lenses with high water content are of great benefit in treating several ophthalmic diseases. Soft contact lenses can absorb water soluble drugs and release them into the eye over a prolonged duration.
These lenses are specially useful in promoting substained release of solutions or suspensions that normally would be removed quickly from the external ocular tissues.
Therapeutic soft contact lenses are used commonly as drug delivery devices in the management of dry eye disorders.
Sometimes these lenses are also used for the treatment of ocular infections, specially bacterial corneal ulcers.
Corneal Shields
Porcine or bovine scleral collagen shields are commercially available which are usually non-cross linked and homogenized.
Corneal shields are generally placed as a bandage on the cornea following surgery or injury to protect and lubricate the cornea.
For treating bacterial corneal ulcers corneal shields are used in conjunction with topical antibiotics with good results.
Cotton Pledgets
Small cotton pieces can be soaked with topical ophthalmic solutions and placed in conjunctival sac.
Such devices certainly allow a prolonged ocular contact time with solutions that are normally instilled topically into the eye.
Generally cotton pledgets are used for the administration of mydriatic solutions.
This drug delivery device promotes maximum mydriasis in an effort to break posterior synechiae or to dilate sluggish pupils.
Filter Paper Strips
Fluorescein strips are commercially available as drug impregnated filter paper strips (Sodium Fluorescein, Rose Bengal or Flurexon).
These filter strips help to ensure sterility of sodium Fluorescein which can be easily contaminated with Pseudomonas aergenosa when prepared in solution.
These test strips are used diagnostically to identify corneal injuries and infections.
Schirmer tear test strips are also available commercially for diagnosing dry eye disorders.
Artificial Tear Inserts
A specially designed rod-shaped pellet of hydroxy propyl cellulose without preservative is commercially available to be inserted into the inferior conjunctival sac with a special applicator.
Following insertion, these devices absorbs fluid, swells and then releases the nonmedicated polymer to the eye for a duration of 24 hours.
Ocuserts are specially used in the treatment of dry eye disorders.
Membrane Bound Inserts
Ocuserts are membrane controlled drug delivery system which deliver a constant quantity of medication to the eye for a week continuously.
Pilocarpine Ocuserts are commonly used in the treatment of glaucoma. These Ocuserts are placed on to bulbar conjunctiva under the upper or lower eyelid.
Pilocarpine Ocusert is a useful substitute for Pilocarpine drops or gel in glaucoma patients who have poor compliance with more frequent drug instillation.
OPTOMETRY-SHARP VISION
Optometrist