Artificial Tears

Artificial tears are over the counter eye drops that are used to treat dry eyes. They work by adding volume to the tear film. This can only occur, however, while the film remains in contact with the surface of the eye. Artificial tears require some agent that will allow them to remain in contact with the eye surface. This is called a viscosity enhancing component. Hydrogels are the viscosity enhancing component most commonly used in artificial tears. Artificial tears may also contain glycine, magnesium chloride, and zinc chloride, all of which are found in natural tears. Sodium borate, a mild antiseptic, and other desirable ingredients may also be included.

Despite the addition of viscosity enhancing components, artificial tears still have a relatively short retention time on the eye surface, limiting their effectiveness. Scientists are currently experimenting with ingredients that have some bio-adhesive properties, such as Systane, to lengthen the eye surface contact time.

A wide selection of artificial tears are available. The following guide will help you to select the right type for your condition:

*** Moderately hypotonic artificial tears has been shown to promote ocular surface disease healing in severe dry eyes. Available hypotonic tears include: Thera Tears, Hypotears and Akwa Tears.

(Br J Ophthalmol. 2002 Aug;86(8):879-84, Ophthalmologica. 2001 Mar-Apr;215(2):124-7)

*** Bicarbonate containing artificial tears have been shown to promote healing in severe dry eyes. Available bicarbonate containing tears include: Bion Tears, Murine Tears.

(Arch Ophthalmol. 1995 Mar;113(3):371-8, Cornea. 1993 Mar;12(2):115-20)

*** Oil containing eyedrops (Refresh Endura, Soothe) may be added if meibomian gland dysfunction is present. These eyedrops will replenish the lipid layer of the tear film and prevent tear evaporation.

*** In severe dry eyes and unresponsive surface disease patients have significant visual impairment and disability. In such patients the use of autologus serum eye drops has been shown to help.

.(Br J Ophthalmol. 2004 May;88(5):647-52, Graefes Arch Clin Exp Ophthalmol. 2005 Mar 9)

Punctal Occlusion

Punctal occlusion is a medical procedure in which the tear drain of the eye is closed. In the normal course of events, tears leave the eye through two tiny openings in the corners of the eye. A duct runs from there into the nose. In this operation, small plugs are placed in the ducts, forcing the tears to stay on the eye for a longer period of time. Punctal plugs may be made of either collagen or silicon. Collagen plugs are intended to be temporary and will dissolve within a matter of days. Silicon plugs are permanent, though they can easily be removed by a physician.