3.Night Light Pollution and Ocular Fatigue.
Journal of Korean Medical Science 2018;33(38):e257-
No abstract available.
Fatigue*
4.The Variation of Choroidal Thickness and Refractive Error after Cataract Surgery.
Hyun Cheol ROH ; Choul Yong PARK ; Jong Hyun OH
Journal of the Korean Ophthalmological Society 2016;57(6):924-929
PURPOSE: To evaluate the effect of cataract surgery on subfoveal choroidal thickness (SCT) and investigate the relationship between the variation of SCT and refractive error. METHODS: We retrospectively reviewed the medical records of 47 patients (47 eyes) who underwent uneventful phacoemulsification cataract surgery from March 2012 to February 2014. SCTs were measured using spectral-domain optical coherence tomography performed before surgery and at 1 month, 3 months and 6 months postoperatively. We investigated the differences in target refraction (TR) and postoperative spherical equivalent (SE), intraocular pressure (IOP) and central macular thickness (CMT) at all follow-ups. RESULTS: Compared with preoperative measurements, SCT showed a significant increase of 5.9 ± 13.3 µm at postoperative 1 month and 7.6 ± 18.1 µm at postoperative 3 months (p = 0.004 and p = 0.006, respectively), but no significant differences at postoperative 6 months (p = 0.104). The correlation between the variation of SCT and the differences in postoperative SE and TR were not significant at 1 month and 6 months, but were positively significant at 3 months (r = 0.310, p = 0.034). The variation of SCT showed no significant correlations with the postoperative change in IOP and CMT. CONCLUSIONS: SCT significantly increased up to 3 months after cataract surgery. The variation of SCT may affect the postoperative refractive error.
Cataract*
;
Choroid*
;
Follow-Up Studies
;
Humans
;
Intraocular Pressure
;
Medical Records
;
Phacoemulsification
;
Refractive Errors*
;
Retrospective Studies
;
Tomography, Optical Coherence
5.Considering Spherical Aberration in Choosing the Wavefront Map for Laser Vision Correction.
Sung Min AHN ; Su Sie SEOK ; Choul Yong PARK
Journal of the Korean Ophthalmological Society 2011;52(2):147-156
PURPOSE: To report the dynamic nature of human optical aberrations in the scotopic condition. METHODS: A total of 20 eyes who were candidates for laser vision correction were included in the present study. Repeated wavefront data were obtained using WavescanTM (AMO/VISX). From the wavefront analysis data, the sphere, astigmatism, average pupil size, spherical aberration, coma and trefoil were selected and used to investigate any correlation among the parameters. RESULTS: The sphere, spherical aberration, coma and pupil size showed a dynamic change in the scotopic condition. The spherical aberration and pupil size decreased by the amount of 0.10 +/- 0.04 microm and 0.55 +/- 0.37 mm as the sphere changed 1 D in myopic direction. There was significant positive correlation between the sphere and spherical aberration in 13 eyes of 9 patients (65%), between the sphere and pupil size in 5 eyes of 4 patients (25%), and between the sphere and coma in 3 eyes of 3 patients (15%). The spherical aberration decreased significantly in 4 eyes of 4 patients (20%) as the pupil size decreased. CONCLUSIONS: The optical aberration of human eyes showed a dynamic nature in the scotopic condition. In particular, there was significant correlation between the sphere and spherical aberration. The observed correlations have the potential to be used as helpful indicators to select the optimal wavefront data for the laser vision correction.
Astigmatism
;
Coma
;
Eye
;
Humans
;
Lotus
;
Pupil
;
Vision, Ocular
6.The amendment tendency analysis of the Korean Infectious Disease Prevention Act and a recommendation for the next amendment.
Chang Yong WHANG ; Hee Choul OHR ; Duk Hyoung LEE ; Ki Dong PARK ; Jong Koo LEE
Korean Journal of Preventive Medicine 1998;31(3):540-563
This Study has been carried out to make a recommendation for the next amendment of the Infectious Disease Prevention Act with a specific focus on the kind of notifiable disease. Korean, Japanese, German, U.S, English and French acts on infectious diseases prevention were reviewed, compared with and analyzed in regards of numbers and kinds of notifiable infectious diseases and their tendency of amendments. An criteria was designed to assess the level of validity of diseases to be designated in the act. Four items, the fatality (greater than 10% or not), the possibility to make a big epidemic, the availability of efficient vaccination and the usefulness of isolation, are used in the assessment. This index is applied to the diseases in Korean and other countries' Infectious Disease Prevention Acts. Results are as follows : 1. The Korean Infectious Disease Prevention Act has a unique way of classifying the notifiable infectious disease, that is, the first, the second and the third class. But the author cannot find the basis of classification. No other countries reviewed have the similar classification. 2. The ten diseases, cholera, plague, yellow fever, diphtheria, typhoid fever, poliomyelitis, rabies, tetanus, malaria, and meningococcal meningitis are designated as the notifiable diseases not only in Korea but also in Japan, Germany, United States, England and France. 3. Thirty seven diseases including small pox, Lassa fever, anthrax, influenza, German measles, Legionellosis, infection with E. coli O157:H7, Q-fever, brucellosis, Lyme disease are designated as legal disease at least one of the above mentioned countries. 4. The Korea has been coped with the change of the infectious disease occurrence for last fifty years in amendment of the Infectious Disease Prevention Act. 5. Japan has a special infectious surveillance system composed of 3,880 clinics throughout the whole country. 6. Germany has classified infectious diseases in five categories which are based on seriousness of disease. Any confirmed death, cases and suspected cases in class I should be reported within 24 hours. But only confirmed death and cases in class II, but not suspected cases, are repotable in Germany. 7. Plague, bacillary dysentery, pertussis, mumps, Japanese encephaltis and Korean hemorrhagic fevers are diseases with high credits validity index among Korean legal disease. 8. German measles, anthrax, E. coli O157:H7 infection, Lassa fever, Q-fever, brucellosis are high in validity index among those which are not designated in Korea but designated in other countries. In conclusion, the Korean Infectious Disease Prevention Act has well been coped with the changes of infectious disease occurrence for last fifty years, but the classification basis and the validity of diseases to be designated as legal diseases is worth reevaluating.
Anthrax
;
Asian Continental Ancestry Group
;
Brucellosis
;
Cholera
;
Classification
;
Communicable Diseases*
;
Diphtheria
;
Dysentery, Bacillary
;
England
;
Fever
;
France
;
Germany
;
Humans
;
Influenza, Human
;
Japan
;
Korea
;
Lassa Fever
;
Legionellosis
;
Lyme Disease
;
Malaria
;
Meningitis, Meningococcal
;
Mumps
;
Plague
;
Poliomyelitis
;
Rabies
;
Rubella
;
Tetanus
;
Typhoid Fever
;
United States
;
Vaccination
;
Whooping Cough
;
Yellow Fever
7.Optical Coherence Tomography in the Evalution of Fitering Bleb after Trabeculectomy.
Choul Yong PARK ; Chang Won KEE
Journal of the Korean Ophthalmological Society 2003;44(5):1107-1111
PURPOSE: To demonstrate the usefulness of optical coherence tomography in the evaluation of the filtering bleb after trabeculectomy. METHODS: In three eyes of three patients, trabeculectomy was perfomed with the use of Mitomycin C (0.04%). In two eyes, encapsulated filtering bleb was suspected with elevated IOP. Optical coherence tomography (OCT) and ultrasound biomicroscopy (UBM) was performed in three eyes, and the features of the suspected encapsulated bleb and the normal functioning bleb were compared. RESULTS: The encapsulated filtering bleb was characterized by the formation of fluid filled space, which shows very low and homogenous reflectivity, surrounded by a thick wall with high reflectivity in both UBM and OCT. CONCLUSIONS: As the OCT is non-invasive and can obtain image without contact, it is useful to evaluate the filtering bleb at immediate post-operative time.
Blister*
;
Humans
;
Microscopy, Acoustic
;
Mitomycin
;
Tomography, Optical Coherence*
;
Trabeculectomy*
8.Comparison of Nd:YAG Laser Capsulotomy Rates between Implantation of Two Different Aspheric Intraocular Lenses.
Sung Hyun KIM ; Choul Yong PARK
Journal of the Korean Ophthalmological Society 2015;56(2):190-198
PURPOSE: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between 2 different aspheric intraocular lenses, SN60WF and MI-60, in patients who underwent cataract surgery. METHODS: This retrospective study included 404 eyes of 278 patients who were followed up for at least 6 months after cataract surgery. Gender, age, follow-up period and Nd:YAG laser capsulotomy rates between the 2 different intraocular lens groups were compared. RESULTS: The mean follow-up period was 28.1 months in the SN60WF group and 24.3 months in the MI-60 group and the mean age was 68.6 years and 71.3 years in each group, respectively. Follow-up period and age were significantly different between the 2 groups (p < 0.01). Nd:YAG laser capsulotomy rates were 5.6% (13 of 231 eyes) in the SN60WF group and 48% (83 of 173 eyes) in the MI-60 group. Nd:YAG laser capsulotomy rates were significantly higher in the MI-60 group (p < 0.01). Female gender and young age were associated with significantly increased Nd:YAG laser capsulotomy rates (p < 0.01); however, diabetes mellitus was not significantly associated with Nd:YAG laser capsulotomy rates. CONCLUSIONS: Nd:YAG laser capsulotomy rates were higher in the MI60 hydrophilic aspheric intraocular lens group than the SN60WF hydrophilic aspheric intraocular lens group.
Aluminum
;
Cataract
;
Diabetes Mellitus
;
Female
;
Follow-Up Studies
;
Humans
;
Lenses, Intraocular*
;
Retrospective Studies
;
Yttrium
9.Relationship between Ocular Fatigue and Use of a Virtual Reality Device
Sang Hyeok LEE ; Martha KIM ; Hyosun KIM ; Choul Yong PARK
Journal of the Korean Ophthalmological Society 2020;61(2):125-137
PURPOSE: To investigate ocular fatigue after the use of a head-mounted display (HMD)-type virtual reality device.METHODS: Healthy adult volunteers were examined for ocular fatigue before and after watching videos for 10 min with an HMD-type virtual reality device. Subjective ocular fatigue was measured using a questionnaire. Objective fatigue was measured using the critical flicker fusion frequency (CFF), high frequency component of accommodative microfluctuation, and accommodation amplitude. The accommodation amplitude was measured using the push-up method and the dynamic measurement mode of the autorefractometer. Changes in the spherical equivalent were also measured.RESULTS: The questionnaire-based subjective ocular fatigue increased (p = 0.020) after use of the HMD device. In the dominant eye, the high frequency component of accommodative microfluctuation increased (p < 0.05). The accommodation amplitude using the push-up method was decreased in the nondominant eye (p = 0.007), and temporary myopia was observed (p < 0.05). However, there was no increase in ocular fatigue in the CFF or the accommodation amplitude using the dynamic measurement mode, which showed no significant difference before and after using the HMD device (p > 0.05).CONCLUSIONS: A subjective test and some objective tests suggested that use of the HMD-type virtual reality display increased ocular fatigue. However, no increase in ocular fatigue was measured using CFF nor in the accommodation amplitude using the dynamic measurement mode which was a limitation of the study. More studies with the aim to alleviate ocular fatigue after using HMD-type virtual reality devices are therefore needed.
Adult
;
Asthenopia
;
Fatigue
;
Flicker Fusion
;
Humans
;
Methods
;
Myopia
;
Volunteers
10.Bilateral Pterygium and Corneal Keloid in a 9-Month-Old Child.
Choul Yong PARK ; Yong Hoon JI ; Eui Sang CHUNG
Journal of the Korean Ophthalmological Society 2003;44(9):2171-2177
PURPOSE: To report a case with bilateral corneal keloid after pterygium excision. METHODS: A-9-month-old girl presented with bilateral, fibrovascular pterygium which had been rapidly growing to the corneal center since 3 months of age. Seven months postoperatively, avascular, scar-like lesion recurred and was excised. This lesion recurred again 3 months later and phototherapeutic keratectomy was performed. However the mass grew rapidly and was excised surgically at the last follow up. RESULTS: Histopathologic study revealed the feature of corneal keloid such as epithelial layer with variable thickness, markedly increased thickness of stroma, irregularly arranged numerous collagen fibers, abundant fibroblasts and variable size of vascular proliferation. CONCLUSIONS: Pterygium in childhood and corneal keloid are rare entities. To the best of our knowledge, this is the first report of a corneal keloid in a child with bilateral pterygium.
Child*
;
Collagen
;
Female
;
Fibroblasts
;
Follow-Up Studies
;
Humans
;
Infant*
;
Keloid*
;
Pterygium*