Conjunctival Capillary Types and Contact Lenses - Essay Example

The illness most frequently attributed to this part of the body is conjunctivitis, more commonly known as pink-eye, and this infection has helped researchers to understand how wearing contact lenses can affect the conjunctival capillaries: the tiny blood vessels that are responsible for the interchange of oxygen and other substances between the blood and the conjunctiva tissue.

Contact Lens Papillary Conjunctivitis, or CLPC is the most common reason for contact lens wearers to discontinue their usage of lenses. This infection has been directly attributed to the use of contact lenses and in studies using control groups of non-lens wearers it became clear that wearing contact lenses changes the condition of the conjunctival capillaries and therefore the overall condition of the conjunctiva. Studies conducted by Australian researchers showed that while wearing a contact lens, users are reducing the tear and mucus flow under the contact itself, therefore inhibiting the cleansing fluids produced by the conjunctiva from essentially washing away dirt and bacteria. Where the conjunctival capillaries were concerned, the researchers noted a decrease in perfusion, meaning that the capillaries were under pressure and therefore unable to function properly. The compression of the conjunctival capillaries is something that researchers wanted to understand better, in relation to how exactly it affected each lens wearer as opposed to non-contact lens wearers (Augusto et al, 2002).

The conjunctiva relies on working capillaries just like any other tissue within the body so that oxygen can reach it and provide proper nutrition. This is the essential circulation of materials from the bloodstream to the tissue that occurs all throughout the body, and needless to say, the medical and scientific community is interested in understanding just how this basic circulation is affected by the presence of a contact lens. Because lenses slow the conjunctival circulation process, eye-care specialists have been vigilant in monitoring their patients to see whether this will have any adverse effects. Certainly, most contact lens wearers have reported dry eyes and this has been countered with the use of special eye drops designed to keep the eye moist in place of properly working conjunctival capillaries.

Normally, conjunctival blood cells will mimic that of the rest of the body, however, given extensive contact lens use and the susceptibility to conjunctivitis, the presence of white blood cells within the area is often higher than in a non-contact lens wearer. Basically, people who wear contact lenses have to deal with the fact that their conjunctiva is compressed and that the conjunctival capillaries are in turn compressed and unable to supply blood to the membrane in a normal manner. This in turn promotes the build-up of bacteria and dry eyes, which will subsequently call for the production of more white blood cells through the capillaries which are used for healing infections and ridding the membrane of harmful bacteria.

Researchers studying CLPC noticed that lens wearers with the infection, opposed to wearers without the infection, showed no significant differences in the build-up of conjunctival capillary secretions unless the wearers with CLPC continued to wear their contact lenses for an extended period of time. In particular, the secretion of HSA (human serum albumin) was increased dramatically over a longer period of time between CLPC lens wearers and those without the infection (Loftin, Mitchell M., April 2006, http://72.14.253.104/search?q=cache:ATJlgaVgokcJ:www.clspectrum.com/article.aspx%3Farticle%3D13004+conjunctival+capillaries+and+contact+lenses&hl=en&ct=clnk&cd=5&gl=us&client=firefox-a). Researchers working on the project believe that this is due to the influx of white blood cells from the conjunctival capillaries to the conjunctiva to fight off the infection; continued use of the contact lens must therefore serve to irritate the infection and the membrane. Regardless of the higher secretions from conjunctival capillaries when the eye in question is already infected, it is also true that the contact lens wearer will be subject to a higher secretion level from his or her conjunctival capillaries than those someone who does not wear contact lenses.

Scientific research has shown that contact lenses do have a direct effect on the functioning of the conjunctival capillaries and that it is a negative effect. The presence of a contact lens will compress the tissue of the conjunctiva and in doing so compress the very capillaries that serve to nourish the tissue that covers the eyeball and the insides of the eyelids. Without regular, natural nourishment, the tissue can easily become ridden with bacteria and too unhealthy to fight oncoming infections. This leads to the over-activity of the capillaries in delivering white blood cells which are meant to help fight off infections and kill bacteria present in the conjunctiva. It is often a process that comes full circle; in essence, the lens can weaken the conjunctiva and render the tissue unable to defend itself from the subsequent build-up of bacteria.

The challenge for contact lens producers is to manufacture lenses that will put less pressure on the conjunctiva and the conjunctival capillaries so that normal blood flow will take place and wearers are not so susceptible to contracting conjunctivitis.