Laser corrective vision surgery

Clarity of plenty depends upon how well cornea and lens accept rays to fall on to the retina on cones and rods. Light rays refract and bend on to focus on to the retina to regulate a clear image. There are two photoreceptors cones (which color sensitive) and rods (which is dim light sensitive). These send signals to idea though optic nerve. If the shape of the cornea is abnormal light does not fall halally or tight-laced image is not formed on the back of cornea. (Fletcher, 2007) This is called refractive error.This can be corrected by refractive surgery. Refractive errors include myopia (nearsightedness), hyperopia (farsightedness), astigmatism (an irregularly shaped cornea which ca practises blurring), and presbyopia (similar to hyperopia, a condition which causes the lens to harden). Refractive eye surgery helps to reduce or eliminate a persons dependency on eyeglasses or contact lenses. (NYP, 2007) There are several(prenominal) types of refractive surgery proper diagnosti cs can only determine which is needed by whom.It can well be stated that compared with surface ablation, LASIK results in earlier and faster improvement of uncorrected visual acuity, and has less (or almost no) operative discomfort, improved stability, and predictability. (Agingeye, 2007) At the same note it can also be stated that with LASIK, however, the adventures of flap-related complications (wrinkles, debris, folds, exactlytonhole, and diffuse lamellar keratitis) may be associated with the creation of the lamellar flap. (Agingeye, 2007)Precautions of laser correction surgeries are1) Eyes should be healthy2) Patient should be adult3) Stable slap-up deal for a year or so.4) If pregnant surgery should be performed on after evaluating the shape of corneas.5) Should not have Degenerative or autoimmune diseases. (Allaboutvision, 2007)Some of risks in LASIK are1) Some patients lose vision2) Some patients develop debilitating visual symptoms.3) irregular astigmatism, which can decrement the corrected vision4) corneal haze or glare5) overcorrected or undercorrected vision6) inability to gestate contact lenses in the future7) loss of the corneal flap, requiring a corneal graft8) scarring9) infection (Roberts, 2007)10) vision loss11) develop severe dry eye syndrome12) Irregular Astigmatism13) Keratectasia14) Night Vision Problems or Night Glare and Halos15) Central Islands16) Epithelial IngrowthDiffuse Lamellar Keratitis (DLK) (Banerjee, 2005)Lasik has its benefits too. It is performed under a protective layer of corneal tissue. As a result, there is less surface area to heal, less risk of scarring, less risk of corneal haze, less postoperative discomfort, less postoperative need for medications, and vision returns much rapidly, often deep down a day or so. It can an also treat a higher range of vision errors. (Grochmaleye, 2007)One testimony to this is available from the US military. It is stated that the U.S. military also has adopted widespread use of refractive surgery including LASIK to decrease reliance of troops on artificial lenses or eyewear as prove by the more than 16,000 U.S. Army personnel who underwent refractive surgery from 2000 through 2003. Studies of these outcomes showed that 86% achieved 20/20 or discover uncorrected vision and 98% achieved 20/40 or better, which legally is considered good enough for driving without eyewear or contact lenses. (Allaboutvision, 2007)Some Statistics are in this context can be stated as followsPatient Results Three Months After Treatment Procedure 20/20 or Better 20/40 or Better LASIK for myopia 42.0% to 84.8% 76.8% to 99.4% LASIK for hyperopia 48.8% to 58.3% 93.4% to 98.3% PRK for myopia and hyperopia* 67% (approximate) 95% (approximate) (AAO, 2007) In conclusion it can be stated that the method has both positive and negatively charged aspects. It should be remembered that the use of laser was approved by the FDAs Medical Devices Advisory Committee in the context of the Ophthal mic Devices Panel and the effectiveness and safety was proved with the help of various clinical studies. (FDA, 2007)The FDA evaluated several case studies on the method and after analysis of 1,013 eyes LASIK performances that was carried out in thirteen centers of care for over the period of half year it was found that of the 1,013 eyes treated, 92 percent were corrected to 20/40 or better and 47 percent were corrected to 20/20 or better without glasses or contact lenses. (FDA, 2007) However, in accordance to FDA it could be stated that short-term side effect included pain (for 24 to 48 hours), corneal swelling, double vision and light sensitivity. In many patients these effects lasted for several weeks.(FDA, 2007) Thus this could be termed as a well tested process but it needs more time and application to become a complete water-tight method. It could be stated that more work on the subject is necessary.ReferencesAmerican Academy of Ophthalmology (2007) Ophthalmology Report 2007 Sydney Allied PublicationsAllaboutvision (2007) Lasik Criteria allaboutvision.com retrieved on 10.02.2008 from http//www.allaboutvision.com/visionsurgery/lasik-criteria.htmAllaboutvision (2007) Lasik complication allaboutvision.com retrieved on 10.02.2008 from http//www.allaboutvision.com/visionsurgery/lasik_complication_1.htmBanerjee, D (2007) Details from Medical Journals of AIIMS New Delhi AIIMSFletcher, R (2007) Medical Principals Beliefs and Knowledge Believing and Knowing Dunedin Howard outlayGrochmaleye (2007) Lasik benefits grochmaleye.com retrieved on 10.02.2008 from http//www.grochmaleye.com/lasik_benefits.html