What types of OTC eye-care products are there?

There are seven types of OTC eye-care products available. Each product contains one or more active and inactive ingredients.

1. Artificial tear drop: Lubricants (also called artificial tears) are synthetic (manmade), water-based solutions that are used to lubricate the eye and thicken tears. Artificial tears are formulated as solutions or suspensions, varying in viscosity. Popular examples of artificial tears include AquaSite, Bion Tears, Celluvisc, Duratears, Gen Teal, HypoTears, Liquifilm Tears, OcuCoat, Refresh, Systane, Tears Naturale, and TheraTears. Many people develop sensitivity to the preservatives in these solutions, causing increasing redness, burning or itching. Most of these products are also available in a preservative-free (PF) form. Artificial tears usually are used two to five times a day as needed for relief of symptoms.
2. Ointments or emollients: Ointments also are useful lubricants. These products are not water-based and contain lubricating ingredients similar to petroleum jelly. Examples of ointments include Lacri-Lube, Moisture Eyes PM, and Refresh PM. Their advantage over a water-based solution is that they remain in the eye longer. These ointments cause visual blurring immediately after their use. Therefore, they are often used only prior to sleep.
3. Eye washes: Eye washes (also known as ocular irrigants) are used to cleanse and/or rinse debris from the eye. These products are balanced to the proper acidity and electrolyte concentration so as to be non-irritating to the eye. Washes are available as liquids or drops. These products may contain boric acid with sodium borate, sodium phosphate, or sodium hydroxide to maintain the proper acidity. Examples of washes include AK Rinse, Dacriose, and Eye-Stream.
4. Hyperosmotics: Hyperosmotics are used to treat corneal swelling. Hyperosmotics draw water out of the cornea and thus reduce corneal swelling. Most OTC hyperosmotics contain sodium chloride in various concentrations as either a solution or an ointment. The 2% solution tends to cause less stinging and burning than the 5% solution. An example of a hyperosmotic for corneal swelling is Adsorbonac.
5. Scrubs: Eyelid scrubs are useful for removing oils, debris, or loose skin that can be associated with eyelid inflammation. Soap agents provide the foaming action. An example of this type of product is Eye-Scrub.
6. Decongestants: Decongestants are used to shrink swollen blood vessels in the congested (red) eye, for example, in conjunctivitis. Phenylephrine is the most common decongestant for this purpose. Patients at risk for angle-closure glaucoma should cautiously use phenylephrine because it can cause an attack of the disease. Rebound congestion, in which blood vessels become dilated even with continued use of decongestants, is a common side effect of phenylephrine. Therefore, if no improvement in redness or symptoms occurs within 72 hours of use, phenylephrine should be discontinued. A frequent side effect of phenylephrine is dilation of the pupils. If phenylephrine is absorbed from the eye into the body, an increase in blood pressure may occur, although this is rare. Nevertheless, patients with high blood pressure should be cautious in using phenylephrine. Additionally, if phenylephrine is absorbed, side effects may occur due to interactions with atropine, tricyclic antidepressants (imipramine) and monoamine oxidase inhibitors such as phenelzine sulfate (Nardil) or tranylcypromine sulfate (Parnate), reserpine (Hydropres), guanethidine (Ismelin), or methyldopa (Aldomet).
   
   A second group of chemical decongestants are the imidazoles (naphazoline, tetrahydrozoline, and oxymetazoline). Imidazoles are longer acting than phenylephrine and have fewer side effects, including rebound congestion. Caution still is recommended with imidazoles because of the potential for an increase in blood pressure. Of the three imidazoles, oxymetazoline generally appears to exhibit the least side effects. Naphazoline may dilate pupils more in people with lightly pigmented (blue or green) eyes.
   
   Examples of eye drops containing decongestants are Naphcon, Prefrin, and Opcon A.
   
   
7. Antihistamines: Ocular antihistamines are available OTC. These antihistamines are combined with ocular decongestants for the treatment of congestion (conjunctivitis), particularly when caused by allergy. Pheniramine maleate and antazoline both block histamine receptors in the eye, and thus provide relief from the symptoms of itchy, watery eyes. Antazoline may increase pressure slightly in the eye (of concern to patients with glaucoma) whereas pheniramine maleate has little effect on pressure. Common side effects of antihistamines include burning, stinging, and discomfort in the eye. Important side effects that may be associated with oral antihistamines have not been reported with ocular antihistamines. Antihistamines should not be used in patients at risk for developing angle-closure glaucoma. Examples of products that combine an antihistamine and decongestant are Naphcon A and Ocuhist.
8. Newer allergy eye-drop preparations: Recently, new classes of eye drops for the treatment of itching due to allergy have become available over the counter. Zaditor, a nonsteroidal antiinflammatory drop, is an example of these.