Prescription Additions and Potential Issues - Essay Example

PRESCRIPTION ADDITIONS AND POTENTIAL (DISPENSING) ISSUES This study examines the various aspects of prescription addition and associated dispensing difficulties. Prescription addition is studied with respect to eye disorders like Presbyopia, Cataract, Juvenile stress myopia etc. The various causes of prescription addition due to these disorders are analysed. Dispensing difficulties form an important part of this study. The various types of prescriptions which are difficult to fill and the consequent effect on the patient are analyzed. Pediatric dispensing difficulties are another area of concern. TABLE OF CONTENTS 1. Introduction 1 2. Causes for Prescription Addition 1 3. Dispensing Issues 4 4. Conclusion 6 PRESCRIPTION ADDITIONS AND POTENTIAL (DISPENSING) ISSUES Introduction Eye prescriptions are subject to change due to a variety of reasons. This paper shall examine the various reasons for prescription addition of the eye of an individual. We will examine various common ailments and the reasons due to which these ailments cause a prescription addition. The areas which will be studied in this section are Presbyopia, Anisometropia, squints, the various debilitating effects of diabetes mellitus and juvenile stress myopia. These issues will be studied with respect to their relevance in prescription addition. The other major issue which will be studied is the difficulties in dispensing eye prescriptions. This issue is an often neglected issue, but it has a big effect on the patient as it is the patient who is eventually denied suitable eye care. The dispensing issues which will be examined are aphakic prescriptions, iseikonic lenses, pediatric dispensing, low vision aids and protective spectacles. These dispensing issues will be examined from the patient's viewpoint. Causes for Prescription Addition Presbyopia As mentioned earlier there are numerous causes due to which prescription addition occurs. The most common is Presbyopia, which is caused due to increased age. The main cause of presbyopia is the reduced suppleness of the lens in the human eye. This suppleness is required to focus the objects near the eye. The Ciliary muscle which helps the eye to focus becomes less efficient. The lens loose their ability to alter their focusing power, the capsule which contains the lens in the eye loses its suppleness. The combination of these two factors results in a decrease in the ability to accommodate (reduced accommodation) (Woodruff 2001).This results in progressive prescription addition with the passage of time. Anisometropia Anisometropia is caused due to the differences in the dioptric values between both eyes of a single person. This is generally caused either due to refractive surgery causing a difference in the ability of both eyes. Other reasons are overcorrections of myopic and hyperopic patients. Lastly, Anisometropia is also caused, if one eye is significantly more astigmatic than the other. Irregular astigmatism can cause an imbalance in the refractive power of both the eyes (Woodruff 2001). Prescription addition due to Anisometropia are caused primarily because of either surgery causing a difference in the refractive power between either eyes or the overcorrections of myopic and hyperopic patients. Squint A squint refers to a state where the eyes are not aligned in the same direction Squints are caused by many reasons and occur more in children. As we are focusing on prescription additions, squints especially those that arise from hypermetropia (long sightedness) are treated with the relevant prescription addition. Then the child will be assessed for the decrease of the degree squint and the child's prescription will be changed accordingly. There are various reasons for the occurrence of squints and consequent prescription addition (for the correction of the squint) amongst children. Illnesses like viral fever, measles, and meningitis are known to cause squints. Injury to the nerves attached to the eye muscles can also cause squint. Lastly squints are also hereditary (Goss 2002). Diabetes Mellitus Diabetes Mellitus is responsible for a lot of damage to the eye. Glaucoma occurs when pressure builds up in the eye. In most cases, the pressure causes drainage of the aqueous humor to slow down so that it builds up in the anterior chamber (Grosvenor 2007). The pressure pinches the blood vessels that carry blood to the retina and optic nerve. Vision is gradually lost because the retina and nerve are damaged. Nonproliferative retinopathy is the most common form of retinopathy (Grosvenor 2007). In nonproliferative retinopathy, capillaries in the back of the eye balloon and form pouches. Nonproliferative retinopathy can move through three stages (mild, moderate, and severe), as more and more blood vessels become blocked. In some people, retinopathy progresses after several years to a more serious form called proliferative retinopathy (Grosvenor 2007).Diabetes also has a debilitating effect on various other disorders which get accentuated due to diabetes, to that effect, diabetes is responsible for prescription addition. Juvenile Stress Myopia Juvenile Stress myopia develops in childhood and almost always increases in severity with the progression into adulthood. Myopia is caused by prolonged close work, such as reading or using the computer which causes excessive accommodation, resulting in progressive elongation of the eye (Goss 2002). To reduce the myopic effect, the standard treatment is prescription addition. The extent of myopia will determine the quantum of change in the eye prescription. Cataracts Cataracts normally occur in old people, but it can occur at any age. In younger people, it can result from an injury, trauma, certain drugs, long-standing inflammation or illnesses such as diabetes. It is caused by the lens in the eye becoming opaque. This causes mistiness and blurring of vision. The exact portion of the lens becoming opaque determines the nature and quantum of loss of vision (Grosvenor 2007). Removal of the cataract also involves the insertion of IOL (Intra Ocular Lens. The eye prescription changes accordingly. After cataract surgery, an eye test to determine changes in the prescription is a standard part of the treatment protocol. Dispensing Issues Dispensing issues are diverse in nature. They basically pertain to the difficulties faced while filling out the prescription. There are various prescriptions which are difficult to dispense and therefore cause problem for the patient. Some such prescriptions are; amblyopic lenses (a series of base curves, thicknesses and vertex distances create binocularity, success is dependent on age, refractive error), An astigmatic eye with multiple focal points (http://lenscrafters.com 2007) lenses to correct astigmatism (lenses neutralize the prismatic effect, in the horizontal and vertical meridians, caused by the astigmatic correction whether it be corneal or lenticular), Aniseikonia ( isokonic lenses to correct image disparity related to aniseikonia produced by Anisometropia, which is caused by genetics, cataracts, implants, or trauma), Test image used to quantify image disparity in Aniseikonia (www.opticaldiagnostics.com 2007) and finally colour blindness (information on a patented series of wave length lenses to correct color deficiencies) (Goss 2002). (http://www.moonlight-optics.com 2007) This image shows a patented wavelength lens used to correct color blindness. Pediatric dispensing is a separate domain with its own issues which arise due to prescription addition. Some aspects of pediatric dispensing which are important are frame selection (both the material and the shape), lens options, UV advocacy and finally specialty eyewear (for organised sports) (Koetting 1997). These changes to the prescription have to be made keeping in mind the specialized requirements of children (shatter proof lenses, 'flexible frames' etc). Most of the prescription addition for children occurs due to the reasons mentioned above (except Presbyopia). The constant growth of the child will cause changes in the eye prescription. The treatment protocol of each case determines the exact period for which each eye prescription is valid. Conclusion This paper has studied the various issues which are responsible for a prescription addition. These reasons have been examined in brief. Another major part of the paper is the various dispensing issues. We have detailed the types of prescriptions which may be difficult to fill. Pediatric dispensing has been covered in some detail. References Goss A D & West R W (2002) Introduction to the Optics of the Eye, Butterworth-Hienman, Woburn, MA Grosvenor T.P (2007) Primary Care Optometry, Butterworth-Heinemann, Woburn, MA Koetting RA. (1997) The American Optometric Association's First Century. St. Louis: American Optometric Association Woodruff CE. (2001) The evolution of optometric education in America. J Am Optom Assoc;72(12):779-786. Lens Crafters Inc, 2007, Retrieved on 06 Feb 07, Available online at: http://www.lenscrafters.com Optical Diagnostics Inc, 2007, Retrieved on 06 Feb, Available online at http://www.opticaldiagnostics.com Moonlight Optics Inc, 2007, Retrieved on 06 Feb 07, Available online at http://www.moonlight-optics.com Read More