• Journal of Korean Ophthalmic Optics Society
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• v.16 no.2
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• pp.147-157
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• 2011

Purpose: The present study was conducted to investigate the actual condition of circle lens wear and the differences caused by the pigmentation in blinking rate, non-invasive tear break-up time (NIBUT), and lens surface between circle and soft contact lens wear during clinical application. Methods: Eighty subjects were surveyed to know the actual condition of wearing circle lens. Blink rate, NIBUT of 20 subjects in twenties were measured after separately wearing soft contact lens and circle lens for 5 days. Their lens surfaces were also observed by scanning electron microscope. Results: Fifty percent of circle lens wearers answered that major reason for changing circle lens was discomfort and 67% of answerers wore circle lens more than 6 hours a day. The tendency of increased blink rates in both wearers of circle and soft contact lens at 30 minutes later when tear film stabilized and 3 hour after lens wearing was shown on the 1st, 3rd and 5th day with expanding wearing time. Especially at 3 hours after lens wearing on the 3rd and 5th day, the difference of blink rates was statistically different in circle lens wear and soft contact lens wear. The NIBUTs of soft contact lens wearers and circle lens wearers were 6.0 and 3.7 secs, respectively, at 30 min later on 1st day and were significantly different. NIBUTs of soft contact lens wearers and circle lens wearers were also statistically different 3 hrs after lens wearing on the 1st day and the similar pattern of NIBUTs was shown on the 3rd and 5th day. The roughness of both surfaces in soft contact lens and front surface in circle lens was same. However, pigmented front surface of circle lens was rougher and uneven. Conclusions: As the results, the circle lens wearers might feel discomfort in clinical application since the difference in lens surface of circle lens would change lens wettability during wearing. The difference by tinting contact lens was shown from the result, which could help better wearing circle lens.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.91-98
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• 2000

To investigate the distribution of dry eye and to accept diagnosis methods of dry eye in ophthalmic shop, this study was performed on 81 persons(male : 49, female : 32). 1. We divided two group for diagnosing dry eye by dry eye screening questionnaire : one was dry eye symptom group(49.3%) and the other was non-dry eye symptom group(50.7%). 2. Non-invasive break-up time(NIBUT) which was measured by using Tear $scope^{(R)}$ (Killer. co)was longer than invasive break-up time(IBUT). 3. A blink rate in dry eye symptom group(10%) was measured lesser than 10 cycle/min, in non-dry eye symptom group(14.9%). 4. In shirmer test there were lesser than 10mm/5min in dry eye symptom group(67.5%), in non-dry eye symptom group(39%). 5. Cornea and conjunctival staining by rose bengal represented Mild 25%, medium 36.25%, extreme 38.75% in dry eye symptom group. Non-dry eye symptom group was showed Mild 19.51%, medium 14.63%, extreme 12.19%. 6. These results showed that the patient showed dry eye symptom in 3 items of eye examination was 22.5%, 4 items 25%, 5 items 30%, 6 items 15%.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.27-35
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• 2013

Purpose: The present study was conducted to investigate the changes in the physical properties of RGP lenses induced by the polishing during the process of RGP lens manufacturing, and further evaluate the differences in the actual wearer's comfort and the tear film break-up time caused by these changes. Methods: RGP lenses (fluorosilicone acrylate material) were divided into 4 groups by the different lens-polishing time like 0, 25, 50 and 100 seconds and the thickness, the surface roughness and the wetting angle of those lenses were compared. Furthermore, the comfortability of the lens wear was surveyed after applying these lenses on the subject's eyes with normal tear volume and the non-invasive tear break-up time of the wearers was measured. Results: The central thickness of 4 RGP lenses made of different lens-polishing time was not significantly different however, the lens surface was changed smoother after polishing to be confirmed by scanning electron microscopy. The wetting angle of the RGP lens significantly decreased in accordance with the increase of polishing time. Thus, the difference of approximately $16^{\circ}$ between 0 second and 100 seconds-polishing was statistically significant. The actual wearing feeling of RGP lens was tended to improve in accordance with the increase of the lens wettability however, it was not proportional improvement. The non-invasive tear break-up time of the lens wearers showed different aspect compared with the changes in lens wettability and the actual feeling of RGP lens wear. Conclusions: In this study, better lens wettability, thinner lens thickness, and/or improved lens surface induced by physical stimuli in the process of RGP lens manufacturing was not well-correlated with the increase of actual subjective/objective satisfaction in RGP lens wear. Thus, the consideration of physical properties of the lens as well as the lens wearers' physiological factors in the process of RGP lens manufacturing may be suggested.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.375-381
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• 2011

Purpose: The purpose of this research was to see how wearing either a SCL or a C-SCL effected the dryness of a person's eye depending on how long they wear either type of lens. Methods: This study was carried out on 52 subjects (104 eyes) who were all in their twenties and had previously experienced wearing contact lenses. All of these subjects were required to wear either a SCL or a C-SCL, which were made out of the same material, for three months. Contents such as the McMonnies Questionnaire survey, the blinking rate per min. and the Noninvasive tear break-up time test (NIBUT) were later conducted on the subjects for this study. Results: According to the results of the McMonnies Questionnaire, it was concluded that the longer the subject wore the SCL and C-SCL, the value of the measurements gradually increased. On the other hand, the results from the NIBUT concluded that the longer the subject wore the SCL, the value of the measurements eventually decreased. However, according to the measurements of the blink rate test, it was concluded that neither results had a significant change. Conclusions: It was concluded that long-term wearing of SCL and C-SCL could be the cause of the induction and progression of dry eyes.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.19-28
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• 2008

Purpose: To understand symptoms and signs in soft contact lens wearers the authors evaluate the attribution of the tear test to the contact lens related symptoms and signs. Methods: Sixty-two healthy soft contact lens wearers (23.95${\pm}$4.38 years old, 18.60${\pm}$16.92 months of prior lens wear) were participated in this study. 3 kinds of tear test and McMonnies' questionnaire test were performed for the soft contact lens wearers and subjective symptoms and objective signs were graded using CCLRU scales during the study period. Results: In this surveys, we found ocular dryness, redness and tiredness are the most common frequent and severe symptoms in soft contact lens wearers. Frequency of the ocular dryness, redness and tiredness are associated with grittiness, burning sensation and foreign body sensation respectively, and severity of the photophobia, foreign body sensation are associated with unstable vision and grittiness and which are associated with score of McMonnies' Questionnaire. Conjunctival redness and limbal redness are major signs but those are not need to be clinical care and rarely occurred corneal and conjunctival staining which are associated with tear break-up-time statistically. Conclusions: Dryness, redness and tiredness are primary common symptoms in Korean soft contact lens wearers. The frequency of those symptoms are increased with the period of soft contact lens wear and those are associated with other symptoms but have no relationship with signs.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.4
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• pp.381-388
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• 2012

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.

• Journal of The Korean Ophthalmological Society
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• v.58 no.6
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• pp.706-711
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• 2017

Purpose: To analyze blinking patterns when watching an ultra-high definition (UHD) television and to compare the results between normal eyes and dry eyes. Methods: A total of 59 participants aged from 13 to 69 years were instructed to watch a colorful and dynamic video on a UHD television for 10 minutes. Before and after watching the UHD television, we measured the best corrected visual acuities, autorefraction, tear-break-up-time, degree of corneal erosion and conjunctival hyperemia via slit lamp biomicroscopy. In addition, questionnaires for the evaluation of eye fatigue and symptoms of a dry eye were completed. The definition of dry eye syndrome was that the tear-break-up-time of one of the eyes was less than 5 seconds, conjunctival injection, or marked corneal erosion. The number of blinks and the duration of blinking were both measured and analyzed at the early and late phases of video-watching. Results: After watching the UHD television in the normal eye group, the tear-break-up-time was significantly decreased (p < 0.001) and the degree of corneal erosion was significantly increased (p = 0.023). However, the subjective symptoms of participants were not aggravated (p = 0.080). There were no significant differences in blinking patterns in the dry eye group. On the other hand, in the normal eye group, the mean blinking time was significantly increased (p = 0.030). Conclusions: Watching an UHD television changes the tear-break-up-time, degree of corneal erosion, and blinking pattern in normal eyes, which may increase the risk of dry eye syndrome.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.347-353
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• 2016

Dry eye symptoms can occur by various environmental exposure. This study aimed to investigate the relationship between eye symptom especially dry eye and sunblocks. Study subjects were total 30 (28 male, 2 female) and NIBUT, McMonnies dry eye questionnaire, subjective questionnaire were performed. NIBUT after rubbing sunblocks was decreased compared to that of not-rubbing. Sunblocks C showed the largest difference of NIBUT value and was chosen most uncomfortable sunblocks in subjective questionnaire. Half of the subjects (15) felt eyes discomfort after rubbing sunblocks and showed larger McMonnies dry eye questionnaire score than other subjects. The same result was founded about dry eye suspect criterion. Both showed borderline significant relation(p=0.049, p=0.051). This study suggested that sunblock could cause damage to the eyes and related to dry eye when rubbing sunblock around eyes. Because digital environmental factors could affect stimulus and modify the eyes, a convergence study will be required for additional research.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.497-504
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• 2018

Purpose : The purpose of this study was to investigate the temperature changes of the ocular surface before and after cataract surgery using thermography of a thermal imaging camera. Methods : The study included 75 patients (75 eyes) aged from 50 to 79 years who underwent cataract surgery. In the past, those who underwent corneal-related surgery, wearing contact lens, disorder of tear secretion and taking medication for systemic disease were excluded from this study. The temperature changes of the eyeball surface were measured using a thermal imager (Cox CX series, Answer, Korea) following Tear Break Up Time (TBUT) test, Mcmonnies questionnaire and Schirmer's Test in real time, Results : While the temperature of preoperative ocular surface was $35.20{\pm}0.54^{\circ}C$ and that of postoperative temperature was $35.30{\pm}0.53^{\circ}C$, the difference was not significant. The temperature changes in the ocular surface were statistically significant at $-0.12{\pm}0.08{\Delta}$ ($^{\circ}C/sec$) before the surgery and $-0.18{\pm}0.07{\Delta}$ ($^{\circ}C/sec$) after the surgery. In comparison of the age groups, it was shown that the changes in the surface temperature before the surgery were from $-0.19{\pm}0.05{\Delta}$ ($^{\circ}C/sec$) to $-0.14{\pm}0.09{\Delta}$ ($^{\circ}C/sec$) in the 50s group, and from $-0.12{\pm}0.08{\Delta}$ ($^{\circ}C/sec$) to $-0.15{\pm}0.07{\Delta}$ ($^{\circ}C/sec$) in 60s group, and $-0.18{\pm}0.07{\Delta}$ ($^{\circ}C$) to $-0.12{\pm}0.08{\Delta}/sec$) in the 70s group, showing significant changes in the ocular surface temperature at all ages. Conclusion : Following the cataract surgery, all the indicators of dry eye syndrome were decreased, and eye surface temperature changes were significant. The thermography technique of the ocular surface would be expected to be useful for the evaluation of various dry eye syndromes because it is easy to evaluate dry eye syndrome noninvasively and can be quantified.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.429-439
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• 2013

Purpose: This study was assessed to investigate the change of subjective and/or objective symptoms and the light transmissibility of lens caused by over-usage of daily disposable circle contact lenses (circle lens). Methods: Three daily disposable circle lenses made of etafilcon A, hilafilcon B, and nelfilcon A were applied on 20 normal eyes free from any eye diseases by when subjects complained any kind of discomfort. On the first and the last days of lens wearing, subjective discomfort, blinking rate, non-invasive break-up time, lens centration on corneal surface and visible light transmissibility of lens were recorded at every case and compared. Results: The circle lens wearers complained discomfort when they wore the circle lens more than 15 hours, in excess of 8 hours being the recommended wearing time and the most circle lens wearers quit the lens wearing when they wore more than 30 hours. On the last day of lens wearing, the representative subjective discomforts were stiffness, dryness and tiredness. When the subjects wore circle lens more than the recommended time, a tendency of increased blinking rate and decreased NIBUT was observed when it compared with the values right after lens wearing. On the last day of lens wearing, the lens centration was shown to be decentrated from the pupil center compared with the centration right after the wearing. These changes in lens centration and blinking rate were consistently shown in all cases of lens wearing however, the difference in the degree of subjective and/or objective change was present depending on lens materials and subjects. The visible light transmissibility of circle lens has largely been changed. Conclusions: From these results, it was thought that the decreased NIBUT induced dryness and stiffness and decreased visible light transmissibility caused more blinking when daily disposable circle lens was exceedingly used, which provoked lens decentration and subjective discomfort. However, the difference of subjective and/or objective change was largely varied in accordance with the lens material types and individuality and thus it may occur some unexpected problems by the individual base. Therefore, the education about the necessity to comply with the recommended wearing time and the problem will be essential.