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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Ophthalmic Optics Society
Journal Basic Information
Journal DOI :
The Korean Ophthalmic Optics Society
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Volume & Issues
Volume 17, Issue 4 - Dec 2012
Volume 17, Issue 3 - Sep 2012
Volume 17, Issue 2 - Jun 2012
Volume 17, Issue 1 - Mar 2012
Selecting the target year
Comparative Analysis of Refractive Power on Trial Case Lenses
Moon, Byeong-Yeon ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 321~334
Purpose: In this study, the distribution and differences in refractive powers on trial case lenses were investigated. Methods: We measured refractive powers at optical center and periphery using 4 trial case lens sets. According to international standards, the distribution and uniformity in refractive powers were investigated. Results: The lens shapes were different in different kinds of trial case lenses and some of lenses were out of tolerance according international standards. In some cases, the power differences were found between front and back side as well as between optical center and peripheral regions and also the cylindrical power on spherical lens and spherical power on the cylindrical lens were measured. Conclusions: Trial case lens are used to assess the refractive error, therefore, more precise control of the manufacturing process for trial case lenses and more thorough quality control will be required to offer an accurate vision test. More careful attention in using trial case lens is also required.
A Study on the Business Performance According to Employees(Optician)' Characteristics
You, Min-Jeong ; Sim, Sang-Hyun ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 335~343
Purpose: In this study, we investigated effects of employees characteristics, expertise, customer satisfaction, devotion of employees to their company, business performance of the optician. Methods: For two months, from August to October 2011, employees participated in individual questionnaires. And the SPSS v14.0 was applied for statistical analysis. Results: This study has shown that the employees characteristics have an effect on the financial performance and satisfaction performance of opticians. In particular, the 'Customers satisfaction' a was important characteristics of employees affecting finance performance, and the 'Devotion to their company' was important factor that affects satisfaction performance. Conclusions: From the result found in this study, it is recommended that further efforts for inspiring the employees devotion to their company and for improving customer satisfaction are required. Above all, employer should pay attention on more suitable ways to encourage work of his employee with considering different situation or circumstance of each optician.
A Study On Appropriation of Clinical Practice and Carried Out Task Elements Compare with Job Analysis
Lee, Il-Hoon ; Ryu, Kuyng-Ho ; Jung, Su-A ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 345~352
Purpose: To determine adequacy of clinical practice of current job analysis and to develop standard clinical practice contents. Methods: Actual clinical practice contents were gathered from 2009 to 2011 and compared to job analysis according to gender, practice region, and year. Results: Mean clinical duty days was 24.5 days. An average of 2.74 task elements were identified and performed in a day. The task elements differed and practice content changes were observed in gender, practice region, and year. There was a difference in practice content in task element between male and female in relation to the overall task element of clinical work. Conclusions: There is a need to develop a standard practice content manual containing task elements that meet the requirements of actual clinical practice and education objects of optometry school.
A Study on the Importance and Needs of Clinical Practice in Ophthalmic Optics for Students and Optical Shop Owner
Shin, Jin-Ah ; Jung, Sae-Hoon ; Lee, Ok-Jin ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 353~363
Purpose: To establish basic data for effective clinical practice program by investigating the clinical practice importance and needs for ophthalmic optics students and optical shop owners. Methods: 263 students and 100 optical shop owners who had experience in clinical practice were surveyed in importance and needs of clinical practice and analyzed the results. Results: In general importance for clinical practice, realized the optician's job aptitude
was highest among students and understanding the work of optician
was highest among shop owners. Importance of specific duty for clinical practice, communication strategy & customer service was highest in both students
and shop owners
each. Importance of time & optical shop for clinical practice, supportive guide and education by opticians & shop owner was highest in both students
and shop owners
each. Importance of school support for clinical practice, administrative support for optical shop and students was highest among students
and orientation from the school before clinical practice
was highest among shop owners. In general needs for clinical practice, expanding the clinical practice field
was highest among students and needs of clinical practice in the curriculum
was highest among shop owners. Needs of specific duty for clinical practice, spectacle fitting
was highest among students and ophthalmic dispensing
was highest among shop owners. Conclusions: For effective clinical practice, clinical practice program should be develop which is reflecting the importance and needs of students and optical shop and also cooperation and interest of school and optical shop are required.
Change of Spherical Aberration with Aspheric Soft Contact Lens Wear
Kim, Jeong Mee ; Mun, Mi-Young ; Kim, Young Chul ; Lee, Koon-Ja ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 365~372
Purpose: To investigate ocular higher order aberrations (HOA) and spherical aberration changes caused by an aspheric soft contact lens designed to reduce spherical aberration (SA) of the eye. Methods: Fifty subjects who have successfully experienced soft contact lenses were refitted with aspheric design (Soflens Daily Disposable: SDD, Bausch+Lomb) soft contact lens. Ocular higher order aberrations (HOA) and stand alone SA were measured and analyzed for a 4-mm pupil size using Wave-Scan Wavefront
aberrometer (VISX, Santa Clara, CA, USA). High and low contrast log MAR visual acuity and contrast sensitivity function (CSF) were also measured under photopic and mesopic conditions (OPTEC 6500 Vision Tester
). All measurements were conducted monocularly with an undilated pupil. Results: The RMS mean values for total HOA with SDD contact lenses were significantly lower than those at with unaided eyes (p<0.001) and a reduction for SA in the SDD was close to the baseline SA (zero
) (p<0.001). For the SDD lens, there was a statistically significant correlation between the changes in the total HOA and the contact lens power (r=0.237, p=0.018) as well as between the changes in SA and the lens power (r=0.324, p=0.001). High contrast visual acuity (HCVA) and low contrast visual acuity (LCVA) with SDD lenses were
, respectively under photopic and
, respectively under mesopic condition. Contrast Sensitivity Function (CSF) with SDD lenses under both photopic and mesopic conditions was
, respectively. Conclusions: The SDD contact lens designed to control SA reduced the total ocular HOA and SA of the eye, resulting in compensating for positive SA of the eyes. Thus, the optical benefits of the lens with SA control would be adopted for improving the quality of vision.
A Relationship between Corneal Eccentricity and Stable Centration of RGP Lens on Cornea
Park, Eun Hye ; Kim, So Ra ; Park, Mijung ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 373~380
Purpose: The present study was performed to investigate a relationship between the stable centrations of spherical RGP lens and aspherical RGP lens on cornea and corneal eccentricity. Methods: Two RGP lenses with different designs were fitted in alignment, steep or flat on total 84 eyes having corneal eccentricity of 0.28~0.78. The stable centration of lenses on cornea was analyzed by taking photographs with a high-speed digital camera. Results: The stable centrations of spherical and aspherical RGP lenses in horizontal direction were decentrated to temporal side. More centration to median side was shown when corneal eccentricity was larger. The difference between the stable centrations of spherical and aspheric RGP lenses according to corneal eccentricity was bigger when the fitting state was flatter. The difference in the stable centrations of aspherical RGP lens was smaller than that of spherical RGP lens regardless of fitting status. The stable centrations of spherical and aspherical RGP lenses in vertical direction were located below corneal apex regardless of fitting status however, there was no significant difference analyzed by the variation of corneal eccentricity. However, there were many cases that RGP lenses were in upper eyelid with increasing corneal eccentricity. Conclusions: The consideration of corneal eccentricity is required for RGP lens fitting and manufacturing aspherical RGP lens since the stable centration of spherical RGP lens as well as aspherical RPG lens' centration was changed depending on corneal eccentricity.
The Change in the Parameters of Silicone Hydrogel Lens and Objective/Subjective Symptoms induced by Repetitive Dryness of Lens
Kim, So Ra ; Kang, Byeong Ho ; Jung, In Pil ; Park, Mijung ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 381~388
Purpose: In this study, the changes in the shape of silicone hydrogel lenses, dryness of lens and objective/ subjective symptoms that could be induced by repeating dryness of lens and objective/subjective symptoms were investigated. Methods: After drying and rehydrating of silicone hydrogel lenses with different lens material and thickness for 4 times, their overall diameters and base curves were compared. Subjective symptoms, non-invasive tear break-up time (NIBUTs) and blinking rate were evaluated after wearing dehydrated silicone hydrogel lens. Results: Overall diameter and base curve increased in all tested silicone hydrogel lenses by repeating dryness and rehydration. The degree of change in over all diameter and base curve were variable on the material. There were irregular change of lens parameters in thicker lens. When the subjects wore silicone hydrogel lenses after drying and rehydrating, their NIBUTs were decreased and blink rates were increased regardless of lens material or thickness. In addition, repetitive drying of silicone hydrogel lenses affected the lens fitting. Therefore, subjective symptoms such as itching, pain, irritation, foreign body sensation, dryness tended to be increased. Conclusions: The results obtained from the study may suggest to develop durable silicone hydrogel contact lenses against dry environment since the changes in parameters of silicone hydrogel lens and the subjective discomfort were observed after repetitive drying and rehydration.
Effect of Everted(inside out) Silicone Hydrogel Lens on Corneal Topographical Changes
Kim, Soo-Hyun ; Jeong, Ju-Hyun ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 389~394
Purpose: The purpose of this study was to examine the corneal topographical changes associated with the wearing of everted silicone hydrogel soft lenses. Methods: The shape and fluorescein pattern of everted silicone hydrogel lenses were investigated. The subject wore the silicone hydrogel everted lenses overnight for 8 hours. Objective refractive error and corneal shape were evaluated at baseline, 1, 2, 3, 5, and 7 days after lens wearing and 1,2,3, and 4 days after discontinuation of lens wear. Results: The Fluorescein pattern of everted silicone hydrogel lenses was similar to the reverse geometry lenses with pressure profile. Objective refractive error(sphere power) and corneal refractive power were decreased and corneal shape had changed during the everted silicone hydrogel lenses wear and recovered during the 4 days of discontinuation. Subject experienced no discomfort associated with the everted silicone hydrogel lenses. Conclusions: It appears that everted silicone hydrogel lenses are capable of inducing significant changes in corneal topography, with overnight wear. Further study must be done to help understand these changes to develop a predictable and effective way of using soft contact lenses for corneal reshaping.
An Effect of Visual Acuity Protection by Natural Pigment (Anthocyanine) Extracted from Fermented Purple Sweet Potato
Seo, Eun-Sun ; Ryu, Geun-Chang ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 395~401
Purpose: The purpose of this study was to research any effect on vision protecting or decreasing VDT syndrome of extracted anthocyanine from fermented purple sweet potato and blueberry. Methods: Subjects were aged 19-20 years old who do not have ophthalmic and systemic diseases and over -N4.00 D of refraction error. 40 mg of extracted anthocyanine from fermented purple sweet potato, from blueberry, and control group, placebo were dosed at separate try. After 2 hours later, subjects were directed perform visual display terminal (VDT) work for 2 hours. Objective refractive error was measured before dosing anthocyanine and after VDT work for 2 hours. Degree of head ache, eye pain and strain and subjective symptoms of neck, shoulder and waist was also examined through interviews by dividing its degree into severe, moderate, slight or none. Results: After 2 hours VDT work, vision protection effect in terms of refractive error for dominant eye was decreased by
D in the group of extracted anthocyanine from fermented purple sweet potato,
D in the group of extracted anthocyanine from blueberry. However, there was significantly myopic progression in the placebo group by
D (t=2.27, p=0.03). Conclusions: It is considered that extracted anthocyanine from fermented purple sweet potato inhibits increase of refraction anomalies of dominant eye rather than non-dominant eye after VDT work.
Comparison of Accommodative Response among Emmetropes, Spectacle and Contact Lens Wearer
Lee, Kyu-Byung ; Park, Jeehyun ; Kim, Hyojin ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 403~410
Purpose: The purposes of this study are to investigate accommodative response among emmetropes, spectacle wearer and contact lens wearer, and correlation between refractive error and accommodative respons for each group. Methods: The 72 subjects(144 eyes) who do not have any ocular diseases were participate in this study. Subjects were categorized into emmetropes, spectacle wearer and contact lens wearer by refractive error using closed-field auto-refractometer. We measured dominant eye, naked/habitual visual acuity and refractive error of monocular/binocular vision of refractive error for far/near distance with open-field auto-refractometer and calculated accommodative lag. Results: There were no significant difference of accommodative lag between right and left eye dominant and non-dominant eye, monocular and binocular vision, and spectacle lens wearer and contact lens wearer, However the accommodative lag of binocular vision was severe than monocular vision at near. The lag of myopia was larger than emmetropes, and male was larger than female. Significant correlation was found between refractive error and accommodative lag in total subjects and the same result was found in emmetropes and contact lens wearer. However there were no significant correlation in the spectacle wearer. Conclusions: There were significant difference between emmetrops and myopes in terms of accommodative lag, however accommodative lag of spectacle wearer was not different with contact lens wearer in myopes. There were also significant correlation between refractive error and accommodative lag in emmetropes and contact lens wearer, but the accommodative lag of spectacle wearer was not significantly correlated with refractive error.
Changes of Contrast Sensitivity with Decreasing Luminance in Photopic Conditions
Lee, Eun Jin ; Yoon, Moon Joo ; Kim, Soo-Hyun ; Yang, Gye Tak ; Jeong, Ju-Hyun ; Kim, Hyun Jung ; Kim, Hyun Il ; Choi, Eun Jung ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 411~417
Purpose: To investigate changes of contrast sensitivity with decreasing luminance in photopic conditions. Methods: Contrast sensitivities for 63 university students were investigated at 5 different luminance levels using FACT chart. Results: All contrast sensitivities measured were in the normal range. The peak of contrast sensitivity function was observed to move from 6 to 3 cpd between 40 and
. From an intersection point of two hypothetical lines related with contrast sensitivity for 6 and 3 cpd, we could evaluated that the peak moved from 6 to 3 cpd at about
. When luminance decreases from 120 to
, contrast sensitivity loss at 6 cpd was most, while contrast sensitivity at 1.5 cpd changed little. We could evaluate that at luminance of more than
evaluated approximately, contrast sensitivity was high in the following order of spatial frequency: 18< 12<1.5<3<6 cpd, while at luminance of less than about
as follows: 18<12<1.5<6<3 cpd. Contrast sensitivity losses with decreasing luminance were also evaluated using the decrements and decrement rates of contrast sensitivity. The decrement of contrast sensitivity was the greatest at 6 cpd, while the decrement rate was the greatest at 8 cpd. Conclusions: We propose that evaluation methods used in this research may be available as another methods to evaluate the changes of contrast sensitivity.
The Study of Kinetic Visual Acuity in College Students
Shim, Moon-Sik ; Kim, Sang-Hyun ; Kang, Hye-Sook ; Shim, Hyun-Suk ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 419~424
Purpose: We were to obtain the basic data for studying kinetic visual acuity through the comparative analysis in kinetic visual acuity, visual acuity, refractive error, pupil size, and hand reaction time for college students. Methods: We had tested the kinetic visual acuity, visual acuity, refractive error and hand reaction time using the kinetic visual acuity tester (KOWA AS-4A), the hand reaction time program and auto-refractometer for thirty-nine male and same female optometry students with more than +0.1 LogMAR visual acuity in both eyes. And the results were examined gender differences of kinetic visual acuity and the factors correlation. Results: In the measured values of male, pupil size were 6.00 mm, hand reaction time 0.23 msec, refractive error -1.66 D, visual acuity -0.07, kinetic visual acuity 0.59 and pupil size 5.86 mm, hand reaction time 0.24 msec, refractive error -2.08 D, visual acuity -0.02, kinetic visual acuity 0.46 in female. It was significant difference for kinetic visual acuity values but other factors were not. The kinetic visual acuity and left visual acuity had the highest correlation, r=-0.406. The kinetic visual acuity indicated more excellent values in the case of increasing visual acuity and decreasing myopia amount. Conclusions: It was able to see that male college students were better than female for kinetic visual acuity and the visual acuity were related to kinetic visual acuity.
Optical Analysis of Film Colored Overlay for people with Scotopic Sensitivity Syndrome
Jang, Young-Gun ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 425~433
Purpose: Basic design of virtual colored overlay, film overlay, colored lenses and colored glasses for people with Scotopic Sensitivity Syndrome. Methods: I calculated sRGB and RGB values of the overlays from measured data. I evaluated the relationship between the combinational chromaticities composed of Galaxy Tab white background and film overlays and the chromaticities of pure film overlays. Results: Implementable sRGB and RGB values of the overlays is calculated. The chromaticities of film overlays are different from them with white paper background and them with Galaxy Tab's white background, but showed a certain relationship between them. Light transmittances of Intuitive Overlay are the most (59%-79%) among them and average light reflectance of Reading Ruler is least(8%). Conclusions: The sRGB values and the RGB values are directly applicable to implement assistive tools and the light transmittances are used to calculate
, transparency of virtual overlay in IT devices. It is recommended to consider the chromaticity of white color in implementing virtual colored overlay in the case which the chromaticity is considerably different to theoretical chromaticity of white color.
Development of Dot Sight with 2× Magnification
Lee, Dong-Hee ; Park, Seung-Hwan ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 435~440
Purpose: The purpose of this study is developing the dot sight with a
magnification. Methods: To magnify the target when we see the far through the non-magnified dot sight, we develop the new optical device which is detachable to the non-magnified dot sight. A new optical device is designed to facilitate the transition of an existing non-magnification (
) dot sight to the
magnification dot sight. Results: We could design and fabricate the
afocal optical system which is detachable to the non-magnified dot sight and be composed by a pair of doublet. When the system developed in this study was used, we could aim the external target by twice magnification, so we could further improve the accuracy of aim. Conclusions: We could design and manufacture the
afocal optical system which can be detachable to the non-magnified dot sight. With the results, we could aim the external target by twice magnification, so we could further improve the accuracy of aim.
Design of 1× Optical Path Relay Adapter for Beam Splitting Prism used in Day & Night Scope
Lee, Dong-Hee ; Choi, Gyu-Jung ; Jung, In ; Park, Seung-Hwan ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 441~447
Purpose: This paper is about development and design of the 1x optical path relay adapter for the beam splitting prism by us the day & night scope. Methods: To product the day & night scope by using the beam splitting prism and the commercial zoom optical system with the C-mount lens barrel structure, the optical path relay adapter, which doesn't change the image size of the zoom optical system and can stretch the position of the image-forming surface, is needed. We could design the 1x optical path relay adapter by using the CodeV program in which the Lens Module mode is offered. Results: We could design the optical path relay adapter used in the day&night scope with the beam splitting prism, of which characteristics have the EFL of -56.0 mm, the magnification of +1.0x, the distance from the 1st lens surface to the last lens surface of about 20.4 mm. The resolution of this system is characterized by 30 lp/mm at 40% MTF. This is enough to accommodate the designed optical path relay adapter can overcome the resolution of the 3rd generation of image intesifier tubes. Conclusions: By designing and applying the optical path relay adapter of which optical characteristics have the EFL of -56.0 mm, the magnification of +1.0x, the distance from the 1st lens surface to the last lens surface of about 20.4 mm, and the resolution of 30 lp/mm at 40% MTF, we could develop the new type day&night scope consisting of the beam splitting, the commercial zoom optical system with the C-mount lens barrel structure, and the 3rd generation of image intesifier tubes.
Risk Factors Associated with Cataract by in Middle-aged and Older Korean Adults
Kim, Hyojin ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 449~455
Purpose: This study was found the risk factors of cataract by gender in elder and older Korean adults. Methods: We investigated the data for 5,024 (men 2,163 people, women 2,861 people) people, aged 40-95 years, from the Korean National Health and Nutrition Examination Survey. We divided into two groups (group 1: 40-64 years, group 2: 65-94 years). We divided into two groups (group 1: 40-64 years, group 2: 65-94 years). Cataract was decided in case of at least one eye with lens opacity. We presented significant odds ratio (OR) increase of cataract according to the obesity and socioeconomic information including house income and education level after adjusting for diabetes, hypertension, high triglyceride, outside active, smoking and drinking habits in two groups with distinction of sex. Results: House income (or education) was strongly related to the prevalence of agerelated cataract in all groups. In models adjusting for all other related factors, cataract patients with lower income and education had a higher prevalence of cataract (group1: OR, 1.84[1.17-2.91], OR, 3.00[1.90-4.74], group 2: OR, 3.47[2.53-4.74], OR, 7.44[5.41-10.23] for men. In comparison, for women, cataract patients with lower income, lower education and obesity had a higher prevalence of cataract (group1: OR, 1.72[1.14-2.60], OR, 4.48[2.72-7.38], OR, 1.40[1.10-1.82], group 2: OR, 2.32[1.70-3.16], OR, 29.99[20.31-44.28], OR, 1.27[1.04-1.54]). Conclusions: Factors of low socioeconomic status were associated with age-related cataract in Korean. Obesity-cataract association was stronger in women.
Relationship Between the Prevalence of Allergic Rhinitis and Ocular Symptoms for Children in New Built School
Sim, Jeonggu ; Kim, Ho-Hyun ; Lee, Yong-Won ; Lim, Young-Wook ; Park, Ju-Hee ; Kim, Kwang-Jin ; Kim, Hyojin ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 457~467
Purpose: This study was performed to investigate the relationship between ocular and allergy symptoms in children by environmental pollutants emitted from new constructed building. Methods: Two different types of survey (6-Item Dry Eye Questionnaire and Ocular Surface Disease Index) were used to study dry eye syndromes and ocular subjective symptoms for a six-grade of elementary school students (54 males and 61 females) in newly built buildings in the past three month, located near capital city, Seoul. Atopy and medical history of allergic rhinitis were investigated with using questionnaire for allergy, and also nose itchiness and ocular symptoms were checked as visual analog scale(10-score) with using questionnaire of allergy rhinitis and conjunctivitis under the guideline of ARIA(Allergic Rhinitis Impacts on Asthma). Results: Fifty seven students (50%) from DEQ and 19 students (16.52%) from OSDI were diagnosed as dry eye, and 18 students (15.79%) were diagnosed as dry eye from both questionnaires. It was surveyed that 45 students (39.5%) and 29 students (25.4%) had atopy and allergy rhinitis, respectively. Among 45 students having atopy, 30 students and 8 students were diagnosed as dry eye with using DEQ and OSDI, respectively. And also, 22 students were diagnosed as dry eye by DEQ and 5 students were diagnosed as dry eye by OSDI from 29 students having allergy rhinitis. Among 29 students having both medical history atopy and allergy rhinitis, 15 students detected observable ocular symptom. The complicating allergy symptoms with ocular syndrome were arranged with sneeze, nose itchiness, nose stuffiness, and runny nose in order of frequency. As students recognized eye symptoms, the number of allergy found and student's number were increased proportionally. Conclusions: It was found that children's subjective ocular symptoms were confirmed in the environment as newly built building. The number of student for dry eye was proportionally increased to students having atopy and allergy symptoms.
Comparison of Corneal Asphericity with Measuring Range
Jeon, In-Chul ; Jeong, Woo-Jae ; Kang, Ji-Hun ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 469~476
Purpose: The purpose of this study is to investigate the changes of asphericity according to diameter and direction of the cornea. Methods: The changes of asphericity according to diameter and direction of cornea is measured by using Pentacam(Oculus Co., Germany), as targeting 57 adults (average
, 20 men, 37 women) without any ophthalmic diseases, which may be effective in eyesight, and refractive surgery. Results: As diameter increases in every direction based on the corneal vertex, asphericity has attentively increased (p<0.05), and the size of asphericity in each direction from every measured diameter showed as superior > nasal > inferior > temporal. In group comparison by nearsightness and astigmatism level, asphericity measured high when nearsightness and astigmatism levels were higher, and this appears to be statistically attentive.(p<0.05). Conclusions: Asphericity of cornea significantly increased according to increase of diameter of cornea, and as measured figure or increased quantity appeared differently in all directions based on corneal vertex, so it helps to understand shape of cornea, and considered that is the part to be considered during manufacturing and fitting of RGP lenses.
A Comparative Study on the Ametropias of Philippines and Koreans
Lee, Hark-Jun ; Kwen, Man-Sung ;
Journal of Korean Ophthalmic Optics Society, volume 17, issue 4, 2012, Pages 477~482
Purpose: This study is aimed at finding the conditions of ametropia of adults in the Philippines and the South Korean. Methods: The study objects were 7,695(15,390 eyes) Koreans and 2,256(4,512 eyes) Philippines who visited optic clinics and took refraction test. The distributions of their hypermetropias and myopias about astigmatisms were examined, using the method of equivalent spherical power. When astigmatisms were marked in S-C, cylinder lens diopter and astigmatism axis, presbyopic additions and pupillary distances were analyzed by comparison respectively. Results: Among ametropias of Koreans myopias and hypermetropias were 93.69% and 6.31% respectively and about ametropias of Philippines myopia and hypermetropias were 73.43% and 26.57% respectively. As for spherical equivalent power about Koreans, the results showed that Koreans marked -3.352 D about myopia and Philippines marked -2.213 D about it. There is a gap of -1.139 D between them. About hypermetropia Koreans marked 1.147 D and Philippines, 1.251 D and their gap is 0.104 D. As for ametropia of Koreans there is 49.86% in middle myopia, 32.28% about low myopia, 11.55% about high myopia, and 5.54% about low hypermetropia, 0.75% about middle hypermetropia. As for it about Philippines there is 44.53% in low myopia, 25.11% about middle myopia, 3.79% high myopia and 23.03% low hypermetropia, and 3.51% low hypermetropia respectively. As for cylinder lens there is differences of 0.194 D and 0.22 D between Korean and Philippine for both sexes. Totally Koreans have higher cylinders of 0.175 D than Philippines. As for astigmatism, Koreans have direct astigmatism, inverse astigmatism, and oblique astigmatism in their suffering sequence. As for Philippines, they have direct astigmatism, inverse stigmatism, and oblique astigmatism in their abnormal sequence, and they have higher oblique stigmatism than Koreans. As for presbyopic addition, Philippines have higher distributions than Koreans, and 0.296 D is higher in average. As for pupillary distance, Koreans have longer distance of 0.97 mm in man and 0.63 mm in women than Philippines. Conclusions: As for ametropia, Koreans and Philippines have more myopias than hypermetropias, but Philippines have more rates of hypermetropias than Koreans. And Philippines have more presbyopic additions. Koreans have higher morbidity of inverse astigmatism, and Philippines have higher morbidity of oblique astigmatism comparatively. As for pupillary distance, Koreans have longer length in the body characteristics. This shows that geographical circumstances have much to do with refraction conditions of eyes.