• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.125-131
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• 2015

Purpose: The effect of pigmentation in circle contact lens on lens wearers' tear film stability was investigated in this study. Methods: Non-invasive tear film break-up times of 54 normal eyes before and after lens wearing in twenties and the portion of first tear breakup were measured. The frontal and back surface roughness of circle contact lens was further observed with a scanning electron microscope. The clear lens which was made of hilafilcon B and circle contact lenses which were made of hilafilcon B, polymacon and copolymer of HEMA NVP were tested. Results: Non-invasive tear film breakup time was significantly reduced compared with it before lens wearing. In some case, statistically significant difference in tear film breakup time was also observed between circle contact lenses. The tear file break-up was usually early started in lower than upper portion, and in temporal than nasal portion although there was variation in the lens material. The tear film break-up of circle contact lenses made of hilafilcon B was more commonly observed in peripheral portion(pigmented area) compared with clear contact lens made of same material. Conclusions: The present study revealed that the stability of tear film was affected by wearing circle contact lens and the result seems to be used as the basis for the problem solving that can occur due to the pigmentation when wearing circle contact lens.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.31-42
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• 2014

Purpose: The present study was conducted to investigate the effect of the physical properties of RGP lens induced by lens polishing on the actual wearer's subjective comfort, the tear film break-up time and the blinking rate as a follow-up study that revealed the relationship between the lens physical properties during lens manufacturing and lens wearer's factors. Methods: RGP lenses made from the three different polishing conditions (25, 50 and 100 seconds) were applied on 28 eyes of 17 subjects, aged 20 to 29 years, without any known disease and surgical history in the eyes. While the subjects were asked to wear the RGP lenses longer than a week, the questionnaire for the comfortability was administered everyday. Subjective and objective tear break-up time and blinking rate of the wearers were further measured. Results: The wearer's subjective comfortability showed some difference in the type of discomfort and satisfaction score according to the polishing status when wearing RGP lenses made from different polishing conditions longer than a week, and a bigger difference in satisfaction score induced by polishing condition was especially shown in experienced RGP lens wearer rather than un-experienced wearer. In the case of RGP lens wearer compared with the ones without the wearing experience, as the wearing time increased subjective and objective tear break-up time were increased and the blinking rate was decreased. However, subjective and objective tear break-up time were tended to decrease with even longer wearing time when wearing the RGP lens made from the polishment for 100 seconds. Conclusions: These results confirmed that the optimization of physical properties of the lens may not give the same effect on the wearer's subjective and objective symptoms and other factors when actual wearing. From the results, it can suggest that the success rate of RGP lens wear may be changed by physiological factors such as the stabilization of wearer's tear film, comfortability and lens wearing experience when wearing RGP lens based on 'The manufacturing standard for soft contact lens/hard contact lens' provided by Korea Food and Drug Administration.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.535-540
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• 2012

This study is to research the differences of tear film for young people in of a day in a restricted indoor space. The subjects are 58 eyes volunteers for twice preliminary inspection and tear test of a day. 58 healthy individuals with no eye disease, no body disease, orthophoria, corrective visual acuity more than 0.8, binocular spherical equivalence difference over 0.50 diopter, the flattest corneal curvature in horizontal meridian and the steepest corneal curvature in vertical meridian were tested. The uncorrective visual acuity, refractive error, corneal curvature, schirmer test and tear break up test were performed in the morning and afternoon. Schirmer test were $16.0{\pm}7.0mm$ in the morning and $14.1{\pm}7.1mm$ in the afternoon. TBUT were $11.3{\pm}0.6$ sec in the morning and $12.1{\pm}0.9$ sec in the afternoon. They have no significant differences.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1103-1107
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• 2018

Purpose: To evaluate the clinical effect of intense regulated pulse light (IRPL) and changes in tear film thickness in dry eye patients. Methods: A retrospective study was conducted on 25 patients with Meibomian gland dysfunction who had subjective dry eye discomfort and whose tear film break-up time (TBUT) was < 10 seconds. All patients were treated with IRPL three times on days 1, 15, and 45. TBUT, Schirmer 1 test results, cornea staining score with fluorescein, ocular surface disease index (OSDI), and lipid layer thickness were measured and compared before and after the procedure. Results: TBUT was significantly increased from $3.7{\pm}1.2s$ to $4.4{\pm}2.1s$ after IRPL (p = 0.03). Schirmer 1 test and cornea staining scores changed significantly (p < 0.01 and p = 0.01, respectively). OSDI also showed a statistically significant improvement from $39.5{\pm}17.5points$ to $30.4{\pm}18.7points$ (p = 0.01). However, no significant difference in lipid layer thickness was observed (p = 0.49). Conclusions: IRPL is an effective treatment modality to improve TBUT, Schirmer 1 test scores, cornea staining scores, and subjective dry eye symptoms.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.11-21
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• 2016

Purpose: The aim of this study was to analyze the difference in tear film stability according to the wearing time when wearing clear and circle soft contact lens(circle lens) made of same material. Methods: The clear and circle contact lenses of hilafilcon B and nelfilcon A materials were respectively applied on the subjects classified as normal and dry eyes depending on their tear volume, and their tear film stability was investigated by measuring the non-invasive tear film break-up times, lens centration and the first appearing area of tear breakup after 30 mins and 6 hrs of lens wearing. Results: Non-invasive tear film breakup time significantly reduced with increase of the wearing time for normal and dry eyes when wearing clear and circle contact lenses. The starting ratio of tear film break-up was higher at the peripheral area of clear and circle lenses in all two different materials, and higher at the peripheral area of dry eyes than normal eyes. Starting ratio of tear film break-up was higher at the peripheral area of nelfilcon A lenses compared with hilafilcon B lenses, however, its change with the increase of wearing time showed a different aspect. The number of tear film break-up per unit area when wearing circle lenses of nelfilcon A increased at the central area with the wearing time while its number was higher at the peripheral area when wearing circle lenses of hilafilcon B. The centration of clear lenses made of two materials was closer to pupil compared to circle lenses with the increase of wearing time, however, a larger decentration was shown in dry eyes compared with normal eyes. Conclusions: The research revealed that an effect on tear film stability may be changed by clear lenses as well as circle lenses with coloring process according to the increase of wearing time, and the factors affecting on tear film stability may also vary depending on lens materials. Thus, the appropriate lenses should be selected by the consideration of lens material as well as coloring method/dyes according to the wearers' habit such as daily wearing time and wearing period when trying to wear clear and circle lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.339-346
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• 2010

Purpose: The study was performed to compare the difference of non-invasive tear break-up time (NIBUT) with alignment or steep fitting of soft contact lens in normal and dry eyes. Methods: Total 40 eyes (aged 20~30 years) were classified to the normal (n=20) or dry eye group (n=20) by the diagnosis methods for dry eyes and worn soft contact lens (polymacon material) with alignment or steep fitting. NIBUTs of lens wearers were separately measured at the points of before wearing, immediately after wearing and after stabilization of tear film. Results: With alignment fitting, averaged NIBUT in the dry eye group after stabilization of tear film was not significantly different from that of the normal eye group. However, averaged NIBUTs in the normal and dry eyes had significant difference when measured immediately after lens wearing. However, the number of eyes having NIBUT less than 4.0 second was 30% higher compared to the number of normal eyes with steep fitting when measured immediately after wearing. Some shorten NIBUT in dry eyes with steep fitting was also shown after stabilization of tear film. Conclusions: These results suggest that wearing soft contact lens in dry eyes differently affect tear film compared to normal eyes. Thus, dry eyes need more advertent fitting for contact lens wearing because of unstable tear film.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.519-526
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• 2015

Purpose: To evaluate the changes of OSI value according to tear-film instability measured serially by OQAS(Optical Quality Analysis System, Visiometrics, Spain) every seconds. The presented study analyzed the relationship of the OQAS parameter with the results of the tear-film break-up time, Schirmer test, and the McMonies score. Methods: 147 eyes of 82 subjects were randomly selected from university students (age: $21.51{\pm}3.97$, male 45, female 37). Subjects were measured tear-film break-up time, Schirmer test, McMonies score and once every second for 15 seconds after blinking by continuous measurements from OQAS system. Results: The normal eye groups presented OSI values of $2.13{\pm}1.16$ while the dry eye groups had OSI values of $3.76{\pm}1.42$. Therefore, a significant difference between the normal eye group and dry eye group was discovered (p<0.05). In addition, the OSI value of all subjects increased over time. The OSI value, which was measured every second after blinking occurred, significantly increased between 6 seconds and 7 seconds after the start of the measurement (p<0.05). OSI cut off of 30% (sec.) showed a greater correlation; TBUT (r = 0.855, p = 0.000), McMonies test (r = -0.351, p = 0.003), Schirmer (r = 0.316, p = 0.012). Conclusions: Continuous measurement of OQAS showed a high correlation with the value of the existing dry eye tests. Therefore, Analysis of OSI values by utilization of OQAS could be useful in objectively evaluation of tear film in patients.

• 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 Convergence Society for SMB
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• v.6 no.4
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• pp.85-91
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• 2016

This study is to research the tear film stability for 48 eyes, agreed the purpose of study, didn't have no contact lens wearing and were tested all two times in a day. Their visual acuity was more than 0.8, corrective visual acuity more than 0.8, the fattest K-reading, apical corneal radius, was in 7.40~8.40mm, corneal astigment was less than 1.00D and orthophoria. The tests, tear scope test, tear film break up time test(TBUT) and schirmer test order, were performed their functions before and after their working at interval of 6 hours over. The tearscope test results was no difference, TBUT was no difference, although 1.2 seconds more in the afternoon, shcirmer test was decreased 2.0mm in the afternoon.

• 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%.