Conjunctiva and Contact Lenses - Essay Example

Teacher 26 September 2007 Conjunctiva and Contact Lenses The conjunctiva is the thin membrane covering the white part of the eyeball (the sclera) and the inside of the eyelids, and it is this membrane that scientists are currently studying to further understand the effects of contact lens use on the eyes. In particular, researchers are conducting studies to reveal the specific effects of contact lens use on the density of the cells that make up the conjunctiva. This research will make the kind of information available to contact lens manufacturers and to optometrists for them to better understand diseases and difficulties in contact lens patients. Impression conjunctiva cytology is a way of studying cells, also known as cell biology, and through these studies scientists are able to look directly at cells of any tissue and ascertain their state of health (Anshu et al, 2001). Impression cytology has allowed researchers to look more closely at the cells within the conjunctiva and to study the differences between those tissues that were not exposed to contact lenses and those that were. Various studies have been carried out on various specifications, however it is the cell density that interests many scientists and medical professionals. Cell density, and in particular the density of what are called Goblet cells, are of importance to contact lens studies in relation to the conjunctiva. Cytology of the conjunctiva is best served by the in vivo method which deals with light reflection differently than other methods of study and actually allows the researcher to gain a better view of the tissue in question. Through this methodology, it is possible to have a closer view of the effects that contact lens use is or is not having on the various tissues of the conjunctiva. In vivo methods of study on the eye area will allow doctors and scientists to not only more closely monitor their subjects but to see more clearly through infections on the tissue being studied and specifically to study the conjunctiva through contact lenses which would otherwise prove a hindrance (Doughty, 2000). Conjunctival microscopes are responsible for much of the newer data concerning eye care and health, and in fact this is a unique way for a machine to interpret its own information and have it displayed on a cellular level. Other types of microscopes will focus on certain parts of the tissue that the confocal microscope will pick up; thus scientists are able to attribute not only a cellular picture to the tissue they are studying but to see an actual diagram of the body-part that includes textures as well as placement of the cellular particles. Using in vivo technologies for conjunctival studies means that researchers will also be able to monitor more minute changes in the tissue over time and properly record alterations in the eye over short and long term situations. It is important that such changes be documented so that all possible causes can be identified and weighed; in vivo is very useful in measuring the particulars of eye tissues, such as the blood cell density and other related physical characteristics of the conjunctiva (Jalbert, 2003). Goblet cells are certain cells within different tissues whose primary role is to create and secrete mucus. The name 'Goblet' refers to the actual shape of such cells, which are easily identifiable because of both their shape and their deep red color. These cells are plentiful within the conjunctiva because that is the main objective of the membrane itself: to secrete mucus and subsequently protect the tissues beneath it and keep them free from bacteria (Connor, 1994). It is the hypothesis of many doctors and scientists that the mucus secreted by these cells within the conjunctiva will increase when the tissue is damaged because this would help protect the tissue below the membrane; in turn, it is also assumed that contact lens wearers are more susceptible to eye infections and conjunctival damage. Because of this susceptibility, the logical conclusion is that the conjunctiva of a contact lens wearer will possess more Goblet cells than those of a non-contact lens user. Research conducted at the Southern College of Optometry in Memphis showed that the conjunctiva of contact lens wearers was indeed more susceptible to tearing because of the compression and wear caused by the lenses. The tearing of the delicate membrane led to, after a five month period, the production of more mucus due to the existence of a denser population of Goblet cells. Impression in vivo confirmed the presence of these cells and cemented the opinion that lenses cause a higher population of the specialized cells. Conjunctival morphology refers to the changes between cellular relationships that can occur within the conjunctiva after trauma such as infection or wear and damage. Scientists are always interested to know what kinds of trauma might cause cells to change in this manner and in this case contact lens manufacturers are interested as well because it is necessary that they know whether the lenses can cause such changes in cellular behavior. Based on preliminary studies, it would seem that contact lenses, which are certainly capable of changing the pattern of Goblet cell production and mucus secretion within the entire conjunctiva, may certainly have a link to other changes within the tissue that can cause permanent damage to the tissue or the eye, or simply cause recurring infections. While the Goblet cell density increased with contact lens use, however, the relationships between remaining cells in the tissue maintained normalcy (Gadkari, 1992). Goblet cells are one of the most important factors in the studies of conjunctiva because they can be related to so many different aspects of the tissue and either drop or raise in density within the tissue because of many different factors. Like in all other tissues of the body, it is the body's natural healing particles that bring the attention from the scientific and medical world because these show, essentially, that something is going on in the body. Whether the presence of the cells is a good or bad thing must always be determined, and in the case of the conjunctiva tissue it is these cells that are looked at primarily because their presence has so much to offer in the way of understanding the effects of contact lenses. Studies have shown that the presence of Goblet cells in the conjuctiva is actually because of the compression of the cells within the tissue from the contact lens itself. In people that do not wear contact lenses, the conjunctival capillaries will function normally and therefore allow for the regular flow of oxygen to from the bloodstream into the tissue. It is the role of the conjunctival capillaries (tiny blood vessels) to nourish the conjunctival tissue through this exchange of oxygen and carbon dioxide, and this circulation is what keeps the membrane healthy. In people who regularly wear contact lenses, however, the conjunctiva is put under pressure and compressed by the lens. This compression means that the conjunctival capillaries are under pressure as well, and that the normal circulation of the tissue and the bloodstream is compromised. Compression means that the capillaries are reduced in size and that the nutrients from the bloodstream cannot be carried easily to the tissue for nourishment. In turn, the tissue becomes dry and unclean, which can easily cause infection and other damage. When the conjunctiva is in this state, Goblet cells are created in abundance and more mucus is produced than in a normally functioning conjunctiva (Augusto et al, 2002). Researchers have been correct in many of their assumptions concerning the use of contact lenses and their affect on the sensitive tissues of the eye. The conjunctiva is particularly sensitive to the use of daily lenses since it is this delicate mucus-producing membrane that comes in direct contact with the lenses and must suffer the primary consequences of such a close relationship. Regular use of contact lenses will compress the conjunctiva, and subsequently the conjunctival capillaries whose responsibility it is to provide nourishment to the entire tissue. Less oxygen from the bloodstream means that the tissue becomes unclean and ripe for infection; on top of this it is also under stress daily from the wear and tear of the lens scraping its surface. This unhealthy state motivates the increased production of bacteria-fighters which means that the Goblet cell density of the tissue will increase dramatically in an effort to fight infection and rid the tissue of bacteria. Goblet cells are responsible for the production of mucus, and as this is the role of the conjunctival tissue itself, the presence of more Goblet cells on the conjunctiva means that the eye is having trouble maintaining a static, healthy state. Undoubtedly, and according to the predictions of most doctors and scientists who specialize in this area, the use of contact lenses does have a direct affect on the density of Goblet blood cells because of the minute damage caused daily by the lenses. People who do not use contact lenses will produce fewer of the bacteria-fighting cells. Bibliography Augusto, Azuara-Blanco, Costa, Vital P., Wilson, Richard P., 2002, Handbook of Glaucoma, Martin Dunitz, London. Anshu, M.M., Munshi, V., Sathe, A., Ganar, 2001, Blackwell Synergy, "Cytopathology", http://www.blackwell-synergy.com/doi/abs/10.1046/j.1365-2303.2001.00349.xcookieSet=1&journalCode=cyt. Connor, C.G., Campbell, J.B., Steel, S.A., Burke, J.H., 1994, NCBI, http://www.ncbi.nlm.nih.gov. Doughty, Michael; Blades, Kenneth; Button, Norman; Wilson, Graeme, 2000, Blackwell Synergy, "Ophthalmic and Physiological Optics", http://www.blackwell-synergy.com/doi/abs/10.1046/j.1475-1313.2000.00526.xjournalCode=opo. Gadkari S.S., Adrianwala S.D., Prayag A.S., Khilnani P., Mehta N.J., Shaha N.A., 1992, JPGM Online, "How To Sleep More - Over-The-Counter Remedies May Not Be Enough: Learn About A New Option", http://www.jpgmonline.com/article.aspissn=0022-3859;year=1992;volume=38;issue=1;spage=21;epage=3,22A;aulast=Gadkari. Jalbert, I., Stapleton, F., Papas, E., Sweeney, D.F., Coronea, M., February 2003, British Journal of Ophthalmology, http://www.pubmedcentral.nih.gov/articlerender.fcgiartid=1771516. Read More