"Biotechnology in the Treatment of Sensorineural Hearing Loss" is a great example of a paper on ophthalmology. Malfunctions of special senses often bring about undesirable changes in people’ s health and lifestyle. Developing cataracts and sensorineural hearing losses are just two examples of this. While at the beginning the conditions seem quite easy to put up with, if not handled appropriately they are likely to lead to patients’ loss of vision or hearing. My goal in this paper is to discuss what happens with patients who develop a cataract and describe how this formation represents a variance from regular anatomy and physiology.
Additionally, my goal is to discuss what happens in patients with the sensorineural hearing loss and in what way this condition is different from what is thought to be normal in modern anatomy and physiology. Cataract is a clouding of the natural lens of a human eye. This lens is situated between the iris and the pupil. When it becomes cloudy, it means the patient’ s vision is badly affected. To better understand the nature of the cataract, let us first explore the normal anatomy and physiology of the cataract. Picture 1.
Side View of the Eye Normally, when a person looks at something, the light from this thing goes through the corn, next through the lens, and finally hits the retina which is at the back of the human eye. It is worth mentioning that the eye lens acts similarly to the camera lens (“ Cataracts” ). The eye lens focuses the biggest part of the light which goes through the human eye to what is known as macula. It is one of the parts of retina which hosts the biggest number of seeing cells (Picture 1).
The nerve messages go from these cells (namely, rods and cones) in the human eye retina down certain nerve fibers of what is known the optic nerve to the human brain. The brain interprets the messages, thus enabling people to see. So in order for people to be able to see sharply and clearly, they need to have transparent (in other words, clear) lens of the eye. In this context, the problem with the cataract is that it is a cloudy and even opaque area developing in the lens of an eye.
The lens normally ought to be clear, however in patients with affected lens the vision starts to remind the frosted glass (“ Cataracts” ). A patient that develops a cataract might not feel pain, since the cataract is developing painlessly (“ Symptoms of Cataract” 8). Blurry or in other cases cloudy vision is the major symptom. Despite the fact patients experience the worsening of their vision mostly in one eye, the cataract affects both. Next, patients experience a perception that the colors they see are faded, or that the things they look at are yellowish.
I addition, they might need brighter light when reading and report poor vision at night, halos, as well as glare. Because of the cataract, everything gets dimmer resembling the vision through glasses which need to be cleaned. Occasionally, double vision may take place. Plus, some patients may report a need to change glasses prescriptions frequently (“ Symptoms of Cataract” 8). In the United States, 17% of people have been found to exhibit various degrees of hearing loss (NIDCD, “ What is hearing loss?
A common problem in older adults. ” ). Sensorineural hearing loss is defined as a kind of hearing loss rooted in the malfunction of the vestibucochlear nerve (also known as cranial nerve VIII), as well as the inner ear or the brain’ s central processing centers. The primary cause of the sensorineural hearing loss (SNHL) is either the death or dysfunction of hair cells in the organ of Corti located in the cochlea (Parker 1710). This biological disorder may be induced by the overexposure to noise (Wang, Hirose, & Liberman 248) or to aminoglycoside antibiotics (Forge & Schacht 3).
While in people without the sensorineural hearing loss, hair cells function normally, in patients with SNHL certain regions of Corti get ablated and the rest of the cells make up a flat epitelium which spans what is known as the basilar membrane (Kim & Raphael 612). In addition, while in people not affected by SNHL, the supporting cells whose function is to support the hair cells work normally, in patients diagnosed with SNHL the ionic balance maintained by these supportive cells is ruined as a result of some damage (Raphael & Altschuler 397).
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auditory epithelium.” Cell Cycle, 2007 (6), pp. 612–619.
Forge, A., & Schacht, J. “Aminoglycoside antibiotics.” Audiology & Neuro-Otology, 2000 (5),
Wang, Y., Hirose, K., & Liberman, M. C. “Dynamics of noise-induced cellular injury and
repair in the mouse cochlea.” Journal of The Association for Research in Otolaryngology,
3 (2002), pp. 248–268.
National Institute onDeafness and OtherCommunication Disorders (NIDCD). “What is hearing
loss? A common problem in older adults.” NIH Senior Health. 23 October 2003. Web. 22
March 2012. < http://nihseniorhealth.gov/hearingloss hearinglossdefined/01.html.>.
Parker, M. “Biotechnology in the Treatment of Sensorineural Hearing Loss: Foundations and
Future of Hair Cell Regeneration.” Journal of Speech, Language, and Hearing Research.
December 2011 (54), pp. 1709-1731.