finals journal review

7/31/2019 Finals Journal Review

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THE RELATIONSHIP OF THE OCULAR HEALTH,REFRACTIVE STATUS AND COLOR VISION WITH

THE YEARS IN SERVICE OF SELECTED FLEETMARINES OF THE PHILIPPINE NAVY


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FOREIGN LITERATURE: OCULAR HEALTH

There are many reasons for ocular health problems within the Navy andone of them include those related to toomuch exposure to UV rays. Due toozone depletion, people are now muchmore exposed to these rays. Numerousepidemiological studies and UVexposure assessment surveys pointedout that UV rays have contributed to

increase the risk factor of developing


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UV rays have different categories such as UV-A rays, UV-B rays and UV-C. UV-A is considered the most harmful of the UV rays that could affect our eyes and has awavelength of 315 to 400 nm. These rays can passthrough the cornea and reach the lens and retina insidethe eye. Too much exposure to UVA radiation coulddevelop certain types of cataracts, and according toresearches they may play a role in development of macular degeneration. UV-B is slightly higher than UV-Aas it has a wavelength of 280-315 nm. This is said tocause pterygium, pinguecula and snow blindness or photokeratitis. Moreover, UV-C are the rays closer to thatof visible light rays. They have wavelenths that rangefrom 200-280 nm. Since the cornea absorbs 100 percentof UVB rays, UVB radiation is unlikely to cause cataracts

and macular degeneration, which instead are linked toUVA exposure. 4


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Too much exposure to UVA radiation could developcertain types of cataracts, and according toresearches UVA rays may play a role in developmentof macular degeneration.

Cataract might form because of the chemical changethat occurs within the eyes lens. When a person isexposed to too much direct sunlight within a longperiod of time, the UV radiation from the sun causesthe formation of free radicals. However, even withoutdirect sunlight, like in cloudy days, UV rays can stillpenetrate the eyes. These affect the composition of the lens that results into cataract, and because of this, UV rays are considered as the primary cause of Cataracts. 5


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FOREIGN LITERATURE: REFRACTIVE STATUS

There is a set standard limit to the amount of refractiveerrors allowed when entering the service. It is vital thatthe eyes refraction is determined at the entry medicalexamination. In order to gain entrance to the service, theaspiring naval or military personnel should have a 20/20distance visual acuity correctable by spectacles, contactlenses or surgery. Anything otherwise, say 20/30 in oneeye and 20/70 on the other eye will be rejected. Also,near visual acuity of any degree that does not correct to20/40 in the better eye is will illicit disqualification.Myopia and Hyperopia should not exceed -8.00 and +8.00Diopters, respectively. Moreover, any type of Astigmatismmore than 3.00 Diopters, even refractive errors correctedby orthokeratology and keratorefractive surgery havelesser chances of gaining entry to the service. 13


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In testing gross color vision, Ishihara test plates is themost used color worldwide. It is still the goldstandard for rapid identification of congenital redgreen deficiencies. Given that the major use of

Ishiharas test is a means for assessing occupationalsuitability, the acceptance of very mild deutans is ararely likely to be adopted in these uncommon cases.The normals with low discrimination who fails the testyet cannot be shown to have a congenital red-green

deficiency are interesting and have been termedpigmentfarbanomaly as they fail only printed but notspectral tests. 20


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FOREIGN LITERATURE: COLOR VISION

Pseudoisochromatic plates are the most commoncolor vision tests employed in clinical practice. TheIshihara and Hardy- Rand- Rittler are the mostcommonly used version. Each of these test consist of

a series of plates that contain colored dots of varyingsize and brightness. Persons with color deficienciesare either unable to see the figure against thebackground of other dots.The main advantage of pseudoisochromatic plates isthat they are quick and easy to perform and aretherefore excellent screening procedure for distinguishing normal color vision from any type of color vision abnormality.


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In patients with acquired color vision loss,however, color discrimination may be impairedthroughout the visual spectrum or along aspecific axis, and the deficits may be mild or severe, of sudden onset, asymmetric, and oftenassociated with other visual symptoms or complaints. Tritan (blue) and blue- yellowdeficiencies are most commonly associated with

diseased affecting the photoreceptors and outer plexiform layer, wheras redgreen deficienciesare most commonly associated with diseasesaffecting the optic nerve and posterior visualpathway.


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FOREIGN STUDIES

Cole 16 mentioned that it is known that people with defective color visionmake errors in recognizing signal colors stimulating road traffic signalsand are slower in their response to them - deficiencies that could causedriving errors and accidents. Signal lights on the street are just the sameas signals that are being use by seamen and accidents may happenprior to the presence of color deficiency.

In a survey study regarding color vision defects in clinical practice madeby Cole 17 , one third of the 102 subjects with abnormal color vision saidtheir career choice had been affected by their color vision deficiency,one fourth reported that they had been precluded from an occupationbecause of it and one fourth said they had difficulties with color in their current job. Because it is such a common disorder and has undoubtedpractical consequences for everyday life, optometrists should test thecolor vision of all new patients and provide appropriate advice andcounselling to those who have abnormal color vision, however it is notthe case, as one fifth to one third of adults with abnormal color visionsare unaware of their deficiency.


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In the study of Buckingham, vision readiness was tested on the personnel of the department of defence from September to December 1997. After the study, it shows that 83.3% of them are not visually ready and 73.8% had eye health-related deficiencies. These military personnel onlyundergo eye examination in the preceding 2 years that caused them to be unaware of their visual status.

Also, thorough eye examination should be done to be able to ensure that all the aspects of their vision is normal. Buckingham suggested that theyshould do a four-part screening procedure consisting of (1) a health record review, (2) a case history, (3) a check of individual's spectacles, and(4) a visual acuity check in order to monitor the case of each and every personnel.Checking the vision readiness should have classification system and these are: (1) visual acuity (V), (2) Optical (O), and (3) Eye health (E). Eachvision readiness component should check correctly. In 1992, Maj Andrew Erneston from the U.S. Air Force, studied 68 aircrew members at Seymour Johnson Air Force Base. In his study, he foundout the 75% of them do not have professional ocular examination for the last 2 years and because of this, some of their men were not able toperform their duty well, like being deployment unready which only shows that lack of medical, especially eye care attention could lead to severaldisadvantages and burdens to their duty. The study of Buckingham and Erneston only shows that military personnel should be given much more attention when it comes to their eye healthto ensure all personnel are vision ready prior to deployment. 1

Buckingham RS, Cornforth LL, Whitwell KJ, Lee RB. Visual acuity, optical, and eye health readiness in the military. Mil Med. 2003Mar;168(3):194-8. PubMed PMID: 12685683.

Available from: http://www.ncbi.nlm.nih.gov/pubmed/12685683

Date retrieved: November 15, 2011
http://www.ncbi.nlm.nih.gov/pubmed/12685683http://www.ncbi.nlm.nih.gov/pubmed/12685683


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Farrahmand, Shams and Sharif conducted a study on the War Eye Injuries in Northern Afghanistan, and all outpatients with ocular war injuriesfrom December 1997 to October 1998 were the subjects of the said study.Using the Snellen Chart, Slit Lamp Biomicroscope and Ophthalmoscope, he, together with his team, had the participants eyes checked. Results were: Of 11,000 patients with different eye problems who attended the outpatient department, 116 patients (169 eyes) had war ocular trauma due to different weapons or military explosive material. Twelve persons (10.4%) were blind by WHO definition (

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