Mechanisms Analysis for Fatal Accident Types Caused by Multiple Processes in the Workplace: Based on Accident Case in South Korea.

This study aimed to develop the accident mechanism of fatal accidents taking place in multiple processes at the workplace. Multiple processes were defined as the existence of multiple work types and work processes in the same workspace. Recently, various processes are frequently conducted simultaneously in one workplace with the participation of several companies, and more workers are increasingly experiencing industrial accidents while working in multiple processes. To prevent accidents in the multiple processes caused by the sameness of work period and space, the accident process was investigated by analyzing the investigation reports on serious industrial accidents in South Korea, and then the accident mechanism model was developed. By utilizing the developed model, the major safety measures to be taken by the contractor for each of the 8 types of accidents caused by the multiple processes were drawn. The roles and responsibilities of the contractor to be implemented in order to prevent accident occurrence in multiple processes were proposed through the accident mechanism of each type of fatal accident. It is expected that the accidents taking place in the multiple processes can be prevented with the drawn results.

Types and Characteristics of Fatal Accidents Caused by Multiple Processes in a Workplace: Based on Actual Cases in South Korea.

As the social cost of disasters increases and safety is being emphasized, policy regulations at the national level have been implemented. However, various fatal accidents are continually occurring as continued economic development and enhanced technologies have increased demand and complicated the industrial structure. Workers in different industries, performing similar jobs, often experience different workplace hazards, which can result in similar types of accidents. Therefore, new policy regulations have been established to separate multiple processes and work in workplaces and are being implemented in several countries to minimize damage caused by new types of industrial accidents. Supervision and management appropriate for contractors or safety and health officials with legal obligations are required to play a regulatory role when these types of industrial accidents are likely to occur. This study classified accidental types and their characteristics based on actual cases, in which potential risks exist at multiple processes in a workplace. First, raw data of work-related fatalities that occurred in South Korea were reviewed and classified as fatal accidents caused by multiple processes in workplaces using the proposed method. Next, the classified actual cases were prepared as statistical data and analyzed based on the various categories. Finally, the accident type based on multiple processes, including risks and characteristics, in workplaces was proposed. As a result, this study improved the safety awareness and understanding of regulatory subjects regarding industrial accidents caused by multiple processes in workplaces and is expected to improve the effectiveness of the existing policy to prevent workplace accidents.

Suggestion of an Improved Evaluation Method of Construction Companies' Industrial Accident Prevention Activities in South Korea.

Workers in the construction industry are constantly exposed to dangers during work that can lead to death or disability. Despite recent advances in construction technology, the presence of these risks for workers has become an unresolved social problem. In particular, most companies often recognize that it is necessary to mitigate against risks posed to worker only after an accident has occurred. Recently, there has been an increasing demand for the development of new safety technologies and policy proposals to ensure the safety of workers during construction or work. However, the right solution is not coping after an accident but preventing it, and this must be accompanied by voluntary efforts by the company. To work toward such solutions, Korea is implementing an evaluation of construction companies' industrial accident prevention activities without legal regulations or coercion to encourage voluntary accident prevention activities by companies. The purpose of this study is to propose an effective improvement direction for the system implemented by the Korea Occupational Safety and Health Agency. First, by analyzing the details of the system and the data of the evaluation results, the system's effectiveness and rationality are reviewed, and steps for improvement are determined. Next, an evaluation model is proposed considering the size of the company to be evaluated and the level of safety and health, and its validity is verified through a survey of construction workers. Finally, a plan to induce the voluntary participation of construction companies in this system and the role of the supervisory authority are presented. This study is expected to serve as an important example of an effective safety policy model by encouraging companies' voluntary efforts to prevent accidents in the construction industry and raise the level of potential safety and health awareness.

Porous Si nanowires for highly selective room-temperature NO2 gas sensing.

We report the room-temperature sensing characteristics of Si nanowires (NWs) fabricated from p-Si wafers by a metal-assisted chemical etching method, which is a facile and low-cost method. X-ray diffraction was used to the the study crystallinity and phase formation of Si NWs, and product morphology was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). After confirmation of Si NW formation via the SEM and TEM micrographs, sensing tests were carried out at room temperature, and it was found that the Si NW sensor prepared from Si wafers with a resistivity of 0.001-0.003 Ω.cm had the highest response to NO2 gas (Rg/Ra = 1.86 for 50 ppm NO2), with a fast response (15 s) and recovery (30 s) time. Furthermore, the sensor responses to SO2, toluene, benzene, H2, and ethanol were nearly negligible, demonstrating the excellent selectivity to NO2 gas. The gas-sensing mechanism is discussed in detail. The present sensor can operate at room temperature, and is compatible with the microelectronic fabrication process, demonstrating its promise for next-generation Si-based electronics fused with functional chemical sensors.

Microwave-Assisted Synthesis of Graphene-SnO2 Nanocomposites and Their Applications in Gas Sensors.

We obtained extremely high and selective sensitivity to NO2 gas by fabricating graphene-SnO2 nanocomposites using a commercial microwave oven. Structural characterization revealed that the products corresponded to agglomerated structures of graphene and SnO2 particles, with small secondary SnOx (x ≤ 2) nanoparticles deposited on the surfaces. The overall oxygen atomic ratio was decreased with the appearance of an SnOx (x < 2) phase. By the microwave treatment of graphene-SnO2 nanocomposites, with the graphene promoting efficient transport of the microwave energy, evaporation and redeposition of SnOx nanoparticles were facilitated. The graphene-SnO2 nanocomposites exhibited a high sensor response of 24.7 for 1 ppm of NO2 gas, at an optimized temperature of 150 °C. The graphene-SnO2 nanocomposites were selectively sensitive to NO2 gas, in comparison with SO2, NH3, and ethanol gases. We suggest that the generation of SnOx nanoparticles and the SnOx phase in the matrix results in the formation of SnO2/SnO2 homojunctions, SnO2/SnOx (x < 2) heterojunctions, and SnO2/graphene heterojunctions, which are responsible for the excellent sensitivity of the graphene-SnO2 nanocomposites to NO2 gas. In addition, the generation of surface Sn interstitial defects is also partly responsible for the excellent NO2 sensing performance observed in this study.

Optic disc and peripapillary retinal nerve fiber layer characteristics associated with glaucomatous optic disc in young myopia.

PURPOSE: To explore optic disc and peripapillary retinal nerve fiber layer (RNFL) features associated with glaucomatous optic disc (GOD) in young myopia. METHODS: Presence of GOD, optic disc tilt, and disc torsion were determined using fundus photographs. If the measured disc tilt ratio was >1.3, the optic disc was classified as tilted. Optic disc torsion was defined as a >15° deviation in the long axis of the optic disc from the vertical meridian. The average and four quadrants RNFL thicknesses were assessed using spectral domain optical coherence tomography (SD-OCT). Logistic regression analyses were performed to identify factors associated with the presence of GOD. RESULTS: Nine hundred and sixty myopic subjects were recruited from four refractive surgery clinic databases. The mean age was 26.6 ± 5.7 years and spherical equivalent (SE) was -5.5 ± 2.5 diopters. Among 960 eyes, 26 (2.7%) received GOD group classification. Among 934 normal eyes, 290 (31.0%) had titled optic discs. Eighteen eyes (69.2%) in the GOD group had tilted optic discs. When compared to normal eyes, the GOD group had significantly higher tilt ratios (1.4 ± 0.2 vs. 1.2 ± 0.1, p < 0.001) and less SE (-7.8 ± 2.7 vs. -5.4 ± 2.5 diopters, p < 0.001). Greater tilt ratio (odds ratio (OR) = 4.9, p < 0.001), less SE (OR = 0.708, p < 0.001), and thinner average RNFL (OR = 0.910, p = 0.001) were significantly associated with GOD. Among 934 normal eyes, 366 (39.2%) displayed disc torsion, while among 26 glaucomatous eyes, eight (30.8%) displayed disc torsion. CONCLUSIONS: Optic disc tilt was found in approximately one-third of young myopic eyes and was independently associated with the presence of GOD.

Selective Improvement of NO2 Gas Sensing Behavior in SnO2 Nanowires by Ion-Beam Irradiation.

We irradiated SnO2 nanowires with He ions (45 MeV) with different ion fluences. Structure and morphology of the SnO2 nanowires did not undergo noticeable changes upon ion-beam irradiation. Chemical equilibrium in SnO2/gas systems was calculated from thermodynamic principles, which were used to study the sensing selectivity of the tested gases, demonstrating the selective sensitivity of the SnO2 surface to NO2 gas. Being different from other gases, including H2, ethanol, acetone, SO2, and NH3, the sensor response to NO2 gas significantly increases as the ion fluence increases, showing a maximum under an ion fluence of 1 × 10(16) ions/cm(2). Photoluminescence analysis shows that the relative intensity of the peak at 2.1 eV to the peak at 2.5 eV increases upon ion-beam irradiation, suggesting that structural defects and/or tin interstitials have been generated. X-ray photoelectron spectroscopy indicated that the ionic ratio of Sn(2+/)Sn(4+) increases by the ion-beam irradiation, supporting the formation of surface Sn interstitials. Using thermodynamic calculations, we explained the observed selective sensing behavior. A molecular level model was also established for the adsorption of NO2 on ion-irradiated SnO2 (110) surfaces. We propose that the adsorption of NO2-related species is considerably enhanced by the generation of surface defects that are comprised of Sn interstitials.

Improvement of Gas Sensing Characteristics by Adding Pt Nanoparticles on ZnO-Branched SnO2 Nanowires.

We coated zinc-oxide (ZnO)-branched tin oxide (SnO2) nanowires with a Pt shell layer via a sputtering method and subsequently annealed the composite to generate Pt nanoparticles. The spillover effect of Pt nanoparticles was expected to play a significant role in enhancing the response. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that the nanoparticles were comprised of a cubic Pt phase. A sensing test with NO2 gas revealed that the sensor response to NO2 gas was significantly increased, being related to the spillover effect of the Pt nanoparticles. As a result of the Pt-functionalization, the sensor response time and recovery time were decreased and increased, respectively. The high sensor response and fast response time make Pt-functionalized ZnO branched nanowires a promising candidate for gas sensors. The present work will be useful in exploring new areas of multiple-component nanosystems.

Improved Sensing Behaviors in Reduced Graphene Oxide Functionalized with Ni(OH)2 Nanoparticles.

In this paper, we detail improvements in the sensing properties of reduced graphene oxide (RGO), which were achieved through functionalization. The functionalization process utilizes graphene oxide suspensions, generating nanoparticles on the RGO surface mainly comprised of Ni(OH)2 phase. Raman spectra indicate that functionalization increases the degree of disorder in RGOs. NO2 gas sensing tests reveal an approximate increase of 154% in the sensor response of the RGOs after functionalization. Possible mechanisms for improving sensing responses via functionalization are discussed. The enhancement is due to the spillover effect, to the increase of the sensor surface by the catalytic particles, to the reduction of RGO conduction volume through the generation of depletion region, and to the resistance modulation of the heterojunctions.

Dynamic vaulting changes in V4c versus V4 posterior chamber phakic lenses under differing lighting conditions.

PURPOSE: To compare vaulting changes in eyes implanted with V4c and V4 implantable collamer lenses (ICLs) under differing lighting conditions. DESIGN: Noninterventional, cross-sectional comparative observational case series. METHODS: Fifty-six eyes of 38 patients implanted with V4c ICLs, and 54 eyes of 28 patients implanted with V4 ICLs were enrolled and analyzed. Anterior chamber depth, pupil size and postoperative vaulting were evaluated using a Visante optical coherence tomography system under photopic and mesopic conditions 1 month postoperatively. Refractive errors, keratometry values, axial lengths, intraocular pressures, anterior chamber volumes, and central corneal thicknesses were also recorded. RESULTS: No significant differences were noted in anterior chamber depth between photopic and mesopic conditions in either group. Significant decreases in vaulting and pupil size were detected under photopic conditions in both groups. Moreover, vaulting changes in eyes implanted with V4c ICLs were significantly larger than those in eyes implanted with V4 ICLs. CONCLUSIONS: V4c ICL vaulting decreased more prominently under photopic conditions than did V4 ICL vaulting. Therefore, postoperative vaulting under mesopic and photopic conditions should be considered when interpreting the vaulting of eyes implanted with V4c ICLs.

Long-term results of deep sclerectomy with small collagen implant in Korean.

PURPOSE: To describe the long-term results of deep sclerectomy with collagen implant (DSCI) with or without adjuvant mitomycin C in Korean patients with primary or secondary open-angle glaucoma (OAG). METHODS: This retrospective review was comprised of 65 Korean patients who received DSCI with or without adjuvant mitomycin C due to primary or secondary OAG. Patients were followed for 72 months after surgery. Complete success was defined as intraocular pressure (IOP) <21 mmHg without medication and qualified success was defined as IOP <21 mmHg with or without medication. RESULTS: Mean postoperative follow-up period was 53.0 ± 16.2 months. Mean IOP was 30.5 ± 11.7 mmHg preoperatively, 8.4 ± 4.3 mmHg at postoperative day one and 13.4 ± 3.8 mmHg 60 months after surgery. The mean number of glaucoma medications was decreased from 3.6 ± 1.1 to 1.6 ± 1.3 at 60 months after the operation. Complete and qualified success rates were 36.7% and 79.6% at postoperative 60 months, respectively (Kaplan-Meier survival curve). No shallow or flat anterior chamber, endophthalmitis, or surgery-induced significant cataract was observed. CONCLUSIONS: The results of DSCI in Korean patients presented here seem reasonably excellent with qualified success rates of over 70% at six years with negligible complications.

Glaucoma progression detection by retinal nerve fiber layer measurement using scanning laser polarimetry: event and trend analysis.

PURPOSE: To evaluate the use of scanning laser polarimetry (SLP, GDx VCC) to measure the retinal nerve fiber layer (RNFL) thickness in order to evaluate the progression of glaucoma. METHODS: Test-retest measurement variability was determined in 47 glaucomatous eyes. One eye each from 152 glaucomatous patients with at least 4 years of follow-up was enrolled. Visual field (VF) loss progression was determined by both event analysis (EA, Humphrey guided progression analysis) and trend analysis (TA, linear regression analysis of the visual field index). SLP progression was defined as a reduction of RNFL exceeding the predetermined repeatability coefficient in three consecutive exams, as compared to the baseline measure (EA). The slope of RNFL thickness change over time was determined by linear regression analysis (TA). RESULTS: Twenty-two eyes (14.5%) progressed according to the VF EA, 16 (10.5%) by VF TA, 37 (24.3%) by SLP EA and 19 (12.5%) by SLP TA. Agreement between VF and SLP progression was poor in both EA and TA (VF EA vs. SLP EA, k = 0.110; VF TA vs. SLP TA, k = 0.129). The mean (±standard deviation) progression rate of RNFL thickness as measured by SLP TA did not significantly differ between VF EA progressors and non-progressors (-0.224 ± 0.148 µm/yr vs. -0.218 ± 0.151 µm/yr, p = 0.874). SLP TA and EA showed similar levels of sensitivity when VF progression was considered as the reference standard. CONCLUSIONS: RNFL thickness as measurement by SLP was shown to be capable of detecting glaucoma progression. Both EA and TA of SLP showed poor agreement with VF outcomes in detecting glaucoma progression.

Retinal nerve fiber layer measurement variability with spectral domain optical coherence tomography.

PURPOSE: To evaluate the effect of the scanning laser ophthalmoscope (SLO) guided re-test mode on short- and long-term measurement variability of peripapillary retinal nerve fiber layer (RNFL) thickness obtained by spectral domain-SLO optical coherence tomography (SD-SLO/OCT). METHODS: Seventy five healthy eyes were scanned 3 times per day (intra-session variability) by both the SLO guided re-test mode and the independent mode of SD-SLO/OCT. Subjects were scanned 3 times by both modes at visits within a 2-week interval (inter-session variability). For testing longitudinal variability, 3 separate exams were performed over 6 months by both modes. The coefficient of variation (CV), reproducibility coefficient (RC) and intraclass correlation coefficient of RNFL thickness were compared between the two modes. RESULTS: The intra-session RC and CV ranged from 5.4 to 12.9 microns and 1.76% to 5.72% when measured by independent mode and 5.4 to 12.5 microns and 1.75% to 5.58% by re-test mode, respectively. The inter-session RC and CV ranged from 5.8 to 13.3 microns and 1.89% to 5.78% by independent mode and 5.8 to 12.7 microns and 1.90% to 5.54% by re-test mode, respectively. Intra-session and inter-session variability measurements were not significantly different between the two modes. The longitudinal RC and CV ranged from 8.5 to 19.2 microns and 2.79% to 7.08% by independent mode and 7.5 to 14.4 microns and 2.33% to 6.22% by re-test mode, respectively. Longitudinal measurement variability was significantly lower when measured by the re-test mode compared to the independent mode (average, p = 0.011). CONCLUSIONS: The SLO guided re-test mode for RNFL thickness measurement in SD-SLO/OCT employing a tracking system improved long-term reproducibility by reducing variability induced by inconsistent scan circle placement.

The analysis of AC/A ratio in nonrefractive accommodative esotropia treated with bifocal glasses.

PURPOSE: To report the long term results of bifocal treatment in nonrefractive accommodative esotropia and to analyze the changes of accommodative convergence to accommodation (AC/A) ratio. METHODS: Sixteen patients treated with bifocal glasses for at least 5 years were evaluated retrospectively. Angle of deviation at near and distance, refractive error, and AC/A ratio by the lens gradient method were analyzed. The changes of AC/A ratios were also compared after dividing the patients according to continuation or cessation of bifocal therapy. RESULTS: Six patients (38%; bifocal stop group, BSG) were able to stop using bifocal glasses at an average age of 10.8 years (range, 6.5 to 15.4 years) during their follow-up. However, the other ten patients (62%; bifocal continue group, BCG) had to continue using bifocal glasses until the final visit, which was 13.8 years on average (range, 11.3 to 18.5 years). The AC/A ratio decreased from time of bifocal prescription to the last visit in both groups, from 4.4 to 2.7 in the BSG and from 5.9 to 4.5 in the BCG. AC/A ratios were significantly higher (p = 0.03) in the BCG than that of the BSG from the beginning of bifocal treatment and this difference was persistent until the final visit (p = 0.03). CONCLUSIONS: The AC/A ratio decreased with age in both groups but was significantly higher throughout the entire follow-up period in the BCG. AC/A ratio at bifocal prescription could be an important factor in predicting response to bifocal treatment.

Comparison between deviation map algorithm and peripapillary retinal nerve fiber layer measurements using Cirrus HD-OCT in the detection of localized glaucomatous visual field defects.

PURPOSE: To compare the capability of the deviation map algorithm and peripapillary retinal nerve fiber layer (pRNFL) thickness measurements, both determined using Cirrus spectral domain optical coherence tomography (Carl Zeiss Meditec Inc., Dublin, CA), in discrimination between healthy and glaucomatous eyes. METHODS: This cross-sectional comparative prospective study included 54 patients with glaucoma with localized visual field (VF) defects confined to 1 hemifield and 54 normal controls. Mean pRNFL thickness corresponding to localized VF defect was calculated. A deviation Score (DS) was assigned by customized Image J software (Http://www.rsb.info.hih.gov/ij/18) calculating the number of abnormal superpixels in the deviation maps corresponding to localized VF defect. Correlations between DS and mean pRNFL thickness, and VF parameters were obtained. The areas under receiver operating characteristic curves of the DS and mean pRNFL thickness used for discriminating between controls and glaucomatous eyes were compared. RESULTS: DS and the average pRNFL thickness measurements showed a strong correlation (R, -0.844, P<0.0001). There were also significant correlations between DS, mean deviation (MD), and pattern standard deviation (R, -0.678, 0.699, respectively). The areas under receiver operating characteristic curves of the mean pRNFL thickness (0.892) and DS (0.958) differed significantly (P=0.0051). The sensitivities at 80%, 90%, and 95% specificities were 94.4%, 90.6%, and 88.6%, respectively, for DS and 74.5%, 58.8%, and 47.3%, for mean pRNFL thickness. CONCLUSIONS: The deviation map algorithm showed a superior capability for detection of localized glaucomatous VF defects when compared with traditional pRNFL thickness measurements. There were statistically significant correlations between the deviation map algorithm and VF indices.

Influence of blue light-filtering intraocular lenses on retinal nerve fiber layer measurements by spectral-domain optical coherence tomography.

PURPOSE: The purpose of this study was to assess the influence of blue light-filtering intraocular lenses (IOL) on peripapillary retinal nerve fiber layer (RNFL) thickness measurements by spectral-domain (SD) optical coherence tomography (OCT). METHODS: This prospective study included 50 eyes of 50 patients. Patients were randomly assigned to receive either a blue light-filtering IOL (acrysof IQ (SN60WF) [Alcon]) or a clear IOL (Tecnis (Z9003) [AMO]). The peripapillary RNFL thickness was measured using a Cirrus SD OCT before and 8 weeks after cataract surgery. Perioperative differences in RNFL thickness measurements and signal strengths (SS) were evaluated and compared in both IOL groups. RESULTS: Thirty-nine eyes of 39 patients were included in the final analysis. There was a significant increase in average RNFL thickness and SS after cataract surgery in both IOL groups. No significant difference in perioperative changes of RNFL measurements was noted between yellow and clear IOL groups. In the multivariable analysis, the factor affecting perioperative differences of RNFL measurements was not IOL type but SS. CONCLUSIONS: Our data suggests that blue-light filtering IOL does not influence RNFL thickness measurements by Cirrus SD-OCT.

Residual anterior chamber angle closure in narrow-angle eyes following laser peripheral iridotomy: anterior segment optical coherence tomography quantitative study.

PURPOSE: To study quantitative changes in anterior chamber angle (ACA) after laser peripheral iridotomy (LPI) in narrow-angle eyes using anterior segment optical coherence tomography (AS-OCT). METHODS: Eighteen subjects with narrow angles were imaged with AS-OCT for determining test-retest variability. Forty-six participants with narrow angles were scanned with AS-OCT before LPI and 4 weeks after LPI. The presence of ACA closure by both AS-OCT imaging and gonioscopy was compared before and after LPI. Three ACA parameters by AS-OCT, angle opening distance at 500 µm (AOD(500)), trabecular-ris space area at 500 µm (TISA(500)) and angle recess area at 500 µm (ARA(500)), at both nasal and temporal quadrants were incorporated for analysis. The increment of ACA parameters defined as exceeding the 95% confidence interval of test-retest variability was assessed after LPI. RESULTS: All 3 parameters obtained from the 18 eyes showed good measurement reproducibility (intraclass correlation coefficient 0.850-0.979). Persistent angle closure was detected in 23.9% of eyes by gonioscopy, and in 34.8% of eyes by AS-OCT images at temporal quadrant after LPI. When assessed by measurement variability criteria, the percentage of eyes that showed no significant change in ACA parameters ranged from 23.9% to 45.7% after LPI. CONCLUSIONS: Overall, ACA parameters changed significantly after LPI; however, when assessed by AS-OCT, ACA remained unchanged in some narrow-angle eyes despite LPI. Our findings suggest that multiple causes other than pupillary block may contribute to narrow-angle closure following LPI.

Comparisons of nerve fiber layer thickness measurements between Stratus, Cirrus, and RTVue OCTs in healthy and glaucomatous eyes.

PURPOSE: To compare retinal nerve fiber layer (RNFL) measurements obtained by two spectral-domain optical coherence tomographies (SD OCTs; Cirrus-HD OCT and RTVue) and a time domain OCT (TD OCT; Stratus OCT). The diagnostic ability of the three instruments for glaucoma has also been compared. METHODS: One hundred eight open-angle glaucoma patients and 46 normal controls were enrolled. Three OCT scans were repeated to obtain peripapillary RNFL thickness measurements from all participants on the same day. The relationships between RNFL measurements from three OCTs were evaluated with regression analyses. RESULTS: The thickest RNFL measurements were generally obtained with the RTVue, followed by the Stratus, and finally by the Cirrus OCT (mixed model, p < 0.05). However, the tendency was reversed or no longer present in severe glaucomatous eyes and nasal quadrant maps. Regression analysis between the TD OCT and the two SD OCTs revealed a quadratic relation (linear vs. non-linear, Akaike information criterion, all p < 0.05), whereby RNFL measurements of the TD OCT became exponentially thinner than those by the SD OCTs in thin RNFL thicknesses. Comparing the two SD OCTs, RTVue measured thicker values consistently regardless of the RNFL thickness (pairwise comparisons, p < 0.05). There were no significant differences in the diagnostic ability of all three instruments in average and each quadrants of RNFL thickness (p > 0.05). CONCLUSIONS: Direct comparisons of RNFL thickness measurements among OCT instruments may be misleading as there are considerable differences among devices. The measurement differences between SD OCT and TD OCT differed according to the RNFL thickness and also possibly to severity of the glaucoma. The diagnostic ability of each instrument for glaucoma detection was not significantly different.

Prevalence and characteristics of glaucoma among Korean adults.

PURPOSE: The purpose of this study was to investigate the prevalence and characteristics of glaucoma in the population of the rural Korean town, Sangju. METHODS: Residents of Sangju aged greater than 50 years old were included in this study. Participants completed an interview examining their medical and ophthalmic history Information was collected on the participants' uncorrected and best corrected vision scores, slit lamp examination results, angle width measurements using the Van Herick technique, gonioscopy if the angle width was less than 1 / 4 angle, intraocular pressure (IOP) assessed with the Goldmann applanation tonometry, optic disc examination results, and a visual field test results using frequency-doubling perimetry in cases in which glaucoma was suspected. Glaucoma was diagnosed according to the criteria described by the International Society for Geographic and Epidemiological Ophthalmology. RESULTS: 1,118 residents aged greater than 50 years were examined initially from a population of 2,984 people. Of these, 671 subjects (60%) participated in this study. The prevalence of glaucoma was determined to be 3.4% (95% confidence interval [CI], 2.1-4.8). Open-angle glaucoma with low IOP was determined to be the most common form with a prevalence rate as high as 2.5% (95% CI, 1.8-3.7). Additionally, primary angle closure glaucoma was determined to have a prevalence rate of 0.3% (95% CI, 0.1-0.9). Open-angle glaucoma with low IOP accounted for 94.4% of the open-angle glaucoma cases. CONCLUSIONS: The prevalence of glaucoma among the population of rural Sangju was 3.4%, and open-angle glaucoma with low IOP was the most common form accounting for 94.4% of the total number of cases.