Determination of volatile organic compounds (VOCs) levels from various smoking cessation aids by using gas chromatography-mass spectrometry methodology.

An analytical method was validated and developed to determine the levels of volatile organic compounds (VOCs) including 1,3-butadiene, isoprene, acrylonitrile, benzene, toluene, and styrene from smoking cessation aids using by gas chromatography-mass spectrometry (GC-MS). Seventeen non-ignitable cigarette type of smoking cessation aids, liquid-phase of smoking cessation aids, gas-phase of smoking cessation aids, and ignitable cigarette type of smoking cessation aids were analyzed for levels of six VOCs. The proposed method for six VOCs was validated in satisfactory linearity (R2 > 0.99), recovery (80.38-119.14%). limit of detection (LOD) (0.05-0.19 µg/ml), limit of quantification (LOQ) (0.07-0.18 µg/ml), accuracy (80.47-117.28%), and precision (0.15-7.22%). The mean concentrations of six VOCs were generated in 1,3-butadiene (6.18 µg/cigarette), isoprene (0.34 µg/cigarette), acrylonitrile (0.003 µg/cigarette), benzene (ND = not detected, the lower limit of detection), toluene (0.27 µg/cigarette), styrene (0.13 µg/cigarette). Results showed low levels of VOCs from smoking cessation aid except from liquid-phase of smoking cessation aids. These results are necessary to investigate unintentional hazardous substances generated from smoking cessation aids, and develop accurate analytical method in order to obtain scientific basis for safety management.

Characteristics of diffuse retinal nerve fiber layer defects in red-free photographs as observed in optical coherence tomography en face images.

BACKGROUD: To determine whether diffuse retinal nerve fiber layer (RNFL) defects, identified on red-free fundus photographs, could be identified on optical coherence tomography (OCT) en face structural images and to evaluate which factors are related to the different recognition patterns on en face images. METHODS: This retrospective, cross-sectional study included open-angle glaucoma eyes with diffuse RNFL defects in the inferior hemifield, identified in red-free photographs. The corresponding OCT en face structural images were divided into 3 groups: (1) no defect, (2) localized defect, and (3) diffuse defect. We compared the demographic and clinical ocular characteristics among the groups. RESULTS: A total of 209 eyes from 157 patients were included. The distribution of OCT en face images was: no defect, 25 eyes (11.96%); localized defect, 106 eyes (50.72%); diffuse defect, 78 eyes (37.32%). Logistic regression analysis revealed that eyes with greater mean deviation (P = 0.004) and thicker inferior RNFL (P = 0.008) would be included in the no defect and localized defect groups based on OCT en face images, rather than in the diffuse defect group. CONCLUSION: Around half of diffuse RNFL defects identified in the red-free photographs appeared as localized defects in OCT en face images. Mild glaucomatous damage was related to no defect and localized defect groups, classified based on the OCT en face images, in eyes with diffuse photographic RNFL defects. OCT en face images may be helpful in further assessing diffuse RNFL defects seen in red-free photographs in eyes with open-angle glaucoma.

Comparison of Three Different Tonometers in Eyes with Angle Closure.

SIGNIFICANCE: Precise measurement of intraocular pressure (IOP) is essential when diagnosing and managing glaucoma. We compared the IOP readings of three different tonometers and analyzed agreement among tonometers in eyes with high IOPs. PURPOSE: The purpose of this study was to compare the IOP readings obtained using a Goldmann applanation tonometer (GAT), a rebound tonometer (RT), and a Tono-Pen (TP) in angle-closure eyes with elevated IOP before and after medical IOP-lowering therapy. METHODS: Twenty-five eyes of 25 patients with angle closure and IOPs of greater than 30 mmHg were enrolled. Intraocular pressure was measured using RT (iCare Pro), TP (Tono-Pen XL), and GAT before and after medical treatment. The mean IOP readings of the tonometers were compared before and after treatment. The agreement among the tonometers was assessed via Bland-Altman analysis. RESULTS: The measurements from 22 eyes of 22 patients were suitable for statistical analyses. Before medical treatment, the mean TP-IOP was significantly lower than the mean GAT-IOP (44.0 ± 10.3 vs. 50.4 ± 8.9 mmHg, respectively; P < .001), but no significant difference was evident between the RT-IOP and the GAT-IOP (50.8 ± 10.9 vs. 50.4 ± 8.9 mmHg, respectively; P = .79). After IOP-lowering treatment, the mean GAT-IOP (14.9 ± 4.7 mmHg) did not differ from either the mean RT-IOP (15.6 ± 4.4 mmHg) or the mean TP-IOP (15.4 ± 5.0 mmHg; P = .05 and P = .18, respectively). The random measurement error among tonometers was greater for high IOP readings. CONCLUSIONS: Compared with RT or GAT, TP underestimated IOP in angle-closure eyes with a GAT-IOP of greater than 30 mmHg. Intraocular pressure reading agreement among the three tonometers was lower in eyes with high IOP.

Intraocular Pressure Elevation during Lateral Body Posture in Side-sleeping Glaucoma Patients.

SIGNIFICANCE: In side-sleeping open-angle glaucoma (OAG) patients, eyes that showed progression exhibited a greater intraocular pressure (IOP) elevation when subjects were rested in the lateral decubitus (LD) posture on the ipsilateral side compared with those eyes that did not progress. PURPOSE: The purposes of this study were to investigate whether lying in the LD position for an extended period affects IOP in side-sleeping patients with OAG when rested on their own pillow and to compare posture-induced IOP variations between eyes with recent glaucomatous progression and those without. METHODS: Twenty-eight bilateral OAG patients who reported a preference for side sleeping were included. We measured IOP in both eyes, with the patient in the sitting and supine positions, 5 and 30 minutes after they had been in the right or left LD position (depending on their sleeping habits) and 5 minutes after they had returned to the supine position. While in the recumbent postures, the patients rested on their own pillows from home. The patients were divided into the correspondence and noncorrespondence subgroups, based on whether the laterality of the progressed eye corresponded with their habitual sleeping side. RESULTS: The IOP of the lower-sided eye increased further (+1.6 ± 1.8 mmHg; P < .001) when the LD posture was maintained for an additional 25 minutes. Such time-dependent IOP elevation in the dependent eye was greater in patients whose LD posture corresponded with glaucoma progression (+2.5 ± 1.7 mmHg) than in those who showed no correspondence or no glaucoma progression (+1.0 ± 1.6 mmHg; P = .03). CONCLUSIONS: Compared with nonprogressed eyes, progressed eyes exhibited a greater IOP elevation when the side-sleeping patients with OAG were rested in the LD posture on the ipsilateral side.

Effects of Different Body Postures on the Intraocular Pressure in Patients with Primary Angle-Closure Disease.

SIGNIFICANCE: Eyes with primary angle-closure disease showed higher intraocular pressure (IOP) in the recumbent postures including supine and lateral decubitus (LD) positions compared with the sitting position. PURPOSE: The purpose of this study was to investigate the effects of different body postures on the IOP in eyes with primary angle-closure suspect (PACS), primary angle closure (PAC), or primary angle-closure glaucoma (PACG). METHODS: This is a comparative case series of 31 patients with bilateral PAC disease, such as PACS, PAC, and PACG. The IOP was measured using Tonopen AVIA in sitting, supine, and right or left LD positions. Patients were instructed to rest their heads on the pillows in supine and LD positions. The eye on the lower side in the LD position was called dependent eye. The main outcome was the difference in IOP among different body postures. RESULTS: Among the 62 eyes (31 patients), PACG, PAC, and PACS were noted in 44, 12, and 6 eyes, respectively. The IOP was not significantly different between the two eyes in sitting and supine positions, whereas the IOP was significantly higher in the dependent eye than in the nondependent eye in LD positions. Compared with that measured in the supine position, IOP differences of the dependent eye were higher than those of the nondependent eye when measured in LD position (right LD vs. supine, P = .02; left LD vs. supine, P = .01). In addition, when the study patients were divided into three groups according to their diagnosis, no significant differences were observed in the IOPs and IOP differences among the three groups. CONCLUSIONS: Posture-induced IOP changes were comparable among eyes with PACS, PAC, and PACG.

Retinal vessel diameter in bilateral glaucoma suspects: comparison between the eye converted to glaucoma and the contralateral non-converted eye.

PURPOSE: To investigate retinal vessel diameter in patients classified as bilateral glaucoma suspects who showed unilateral glaucomatous conversion. METHODS: This retrospective study included 21 patients who had initially been diagnosed as bilateral glaucoma suspects but showed unilateral glaucomatous conversion during a follow-up period of more than 2 years. Conversion to glaucoma was determined either by documentation of a new retinal nerve fiber layer defect on red-free photography or a reproducible glaucomatous visual field defect. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured from fundus photographs taken at baseline and at the point of glaucoma conversion. RESULTS: The mean CRAE of the converted eyes was significantly lower than that of the non-converted eyes at baseline (164.9 ± 13.2 µm vs 175.2 ± 15.6 µm; p = 0.001), but no significant difference was observed in the mean CRVE (p = 0.108). The mean CRAE of the converted eyes was also lower than in the non-converted eyes at the point of glaucoma conversion (158.6 ± 13.5 µm vs 168.0 ± 17.2 µm; p = 0.011). CONCLUSION: In bilateral glaucoma suspects, there was a significant inter-eye difference in CRAE at baseline between eyes that converted to glaucoma and those that did not. These findings suggest that measurement of retinal arteriolar diameter may help clinicians when evaluating the risk of conversion in glaucoma suspects.

Head Elevation and Intraocular Pressure in Glaucoma.

PURPOSE: To investigate the effect of different methods of head elevation on intraocular pressure (IOP) in patients with open-angle glaucoma (OAG). METHODS: Seventy-one patients of OAG were included in this prospective observational study. We measured IOP in the sitting position and in the supine positions with head flat and 30-degree up using two different methods: (1) bed head elevation (BHE) and (2) using multiple pillows (MP). We measured IOP using Tonopen AVIA in both eyes 10 minutes after assuming each position in a randomized sequence. By comparing the mean deviation (MD) of visual field between both eyes of a patient, we classified the eyes into either the better-MD eye or worse-MD eye. RESULTS: Compared with that measured in the supine position with head flat, the mean IOP was significantly lower when measured in the supine position with the head 30 degrees up by BHE, with an average drop of 2.0 mmHg (p < 0.001), whereas the mean IOP did not differ significantly when measured in the supine position with head 30 degrees up using MP (p = 0.081). Twenty-five (35.2%) patients showed IOP elevation when the head was kept up by MP. Compared between the better-MD and worse-MD eye, the IOPs did not differ in all positions. The mean IOP of the better-MD eye was lower in the 30-degree head-up (-1.9 mmHg, BHE; -0.8 mmHg, MP) positions compared with that in the flat-lying position, whereas the mean IOP of the worse-MD eye did not differ between the lying flat position and the head-up position with MP. CONCLUSIONS: Different head-elevating methods had different influences on IOPs of glaucoma patients in the supine position. Although raising the bed head by 30 degrees significantly lowers IOP compared to the supine position, resting on multiple pillows does not appear to offer the same IOP reduction in glaucoma patients.

Characteristics of eyes with inner retinal cleavage.

PURPOSE: Inner retinal cleavage can be misdiagnosed as a glaucomatous retinal nerve fiber layer (RNFL) defect. This study was performed to characterize eyes with inner retinal cleavage. METHODS: Inner retinal cleavage is defined as the appearance of a dark spindle-shaped space between the nerve fibers. Patients who presented at our institution with inner retinal cleavage were enrolled in the study. All participants were evaluated by fundus examination, visual field testing with standard automated perimetry, and optical coherence tomography (OCT) imaging. RESULTS: A total of 15 eyes of 11 subjects with inner retinal cleavage were included in the study. The median age of the subjects was 57 years (age range, 30-67 years). In each case, inner retinal cleavage was located adjacent to retinal blood vessels. Tissue bridging the cleavage area was observed in ten eyes. Six eyes had epiretinal membranes (ERMs), two eyes had glaucoma, and one eye had ERM in addition to glaucoma. Six eyes with inner retinal cleavage without combined ocular abnormalities had highly myopic refractive error (-6.50 to -8.50 diopters). Cross-sectional OCT images of the areas of inner retinal cleavage demonstrated defects with irregular margins and empty spaces in the inner layers of the retina. During the follow-up period, no eye showed changes in inner retinal layer cleavage or visual field sensitivity. CONCLUSIONS: Inner retinal cleavage was found in eyes with high myopia or ERMs. Inner retinal cleavage was associated with structural changes distinct from those associated with glaucomatous RNFL defects.

Head position and intraocular pressure in the lateral decubitus position.

PURPOSE: To investigate the effects of different head positions in the lateral decubitus posture on intraocular pressure (IOP). METHODS: Seventeen healthy Korean subjects were included in this prospective observational study. Intraocular pressure measurements were taken with the subjects in the sitting position and the recumbent positions including supine, right lateral decubitus, and left lateral decubitus positions. In right and left lateral decubitus positions, IOP measurements were taken with three different head positions (30 degrees higher, 30 degrees lower, and parallel to the center of the thoracic vertebra) in a randomized sequence. Intraocular pressure was measured using the ICare Pro tonometer in both eyes 5 minutes after assuming each posture. The eye on the lower side in the lateral decubitus position was termed as the dependent eye. We assessed differences in the IOP of the dependent and nondependent eyes in the lateral decubitus positions with different head positions. RESULTS: Regardless of the head position, the dependent eyes showed higher IOP than the nondependent eyes in the lateral decubitus positions except in the left lateral decubitus with high head position (p < 0.001 for all positions except left lateral decubitus, p = 0.083). Low head position significantly increased the IOP of dependent eyes, compared with the neutral or high head positions in lateral decubitus posture. CONCLUSIONS: Low head position elevates the IOP of the dependent eyes compared with neutral head position in the lateral decubitus posture. Proper adjustment of the height of a pillow may help mitigate IOP elevations resulting from lying on the side with a low pillow or with no pillow.

Retinal vessel diameter in normal-tension glaucoma patients with asymmetric progression.

PURPOSE: To investigate the longitudinal changes in the central retinal vessel diameter in asymmetric progressive normal-tension glaucoma (NTG) patients. METHODS: This study included 27 patients with bilateral NTG without any systemic vascular disease who showed glaucomatous progression in one eye at the mean follow-up of 24.3 months (range, 18-29 months). Progression was determined by the development of new retinal nerve fiber layer (RNFL) defects or widening of pre-existing defects on red-free RNFL photographs. The central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE) were measured at baseline and at the mean follow-up of 24.3 months. We classified the eyes of each patient as either progressed or stable eyes, and compared the differences and changes in the CRAE and CRVE. RESULTS: No significant inter-eye difference was observed at baseline in the mean CRAE (167.5 ± 22.2 µm vs. 168.2 ± 15.5 µm, p = 0.809) and in the mean CRVE (276.3 ± 18.2 µm vs. 281.6 ± 21.9 µm, p = 0.267) between the progressed and stable eyes. There were significant changes in CRAE in the progressed eyes between baseline and 2 years after baseline (from 167.5 ± 22.2 µm to 146.9 ± 18.0 µm, p < 0.0001), but there were no significant changes in the stable eyes (from 168.2 ± 15.5 µm to 167.5 ± 14.8 µm, p = 0.084). CONCLUSIONS: In our series of NTG patients with asymmetric progression, central retinal artery diameter decreased over time in the progressed eyes, whereas no significant decrease in the central retinal artery diameter was seen in the stable eyes.

Comparison of intraocular pressure fluctuation and glaucoma progression rate between phakic and pseudophakic eyes in pseudoexfoliation glaucoma.

The management of patients with concurrent pseudoexfoliation glaucoma (PXG) and cataract is challenging given its worse prognosis compared to other glaucoma types and the increased risk associated with cataract surgery. In this retrospective study, we investigated the long-term outcomes of cataract surgery in patients with PXG. We enrolled patients with PXG who had undergone cataract surgery at least 2 years previously and compared them with mean deviation (MD) matched patients with phakic eyes. The results showed that both groups experienced a decrease in MD, with the group of pseudophakic eyes exhibiting a significantly higher rate of decline (-2.15 ± 2.66 dB/year vs. -0.86 ± 0.95 dB/year; P = 0.040). Similarly, there was a trend towards more rapid thinning of the retinal nerve fiber layer in the pseudophakic group (-2.92 ± 2.34 µm/year vs. -1.79 ± 1.71 µm/year; P = 0.074). No significant differences in the intraocular pressure parameters were observed between the two groups. Multivariate analysis revealed that pseudophakic lens status was significantly associated with a faster rate of MD decline in patients with PXG (regression coefficient, -1.391; P = 0.022). These findings underscore the importance of close monitoring of patients with pseudophakic PXG to effectively manage glaucoma progression.

Development of an analytical method to determine methyl alcohol and isopropyl alcohol in food using static headspace gas chromatography.

A method to determine methanol (MeOH) and isopropyl alcohol (IPA) was developed using static headspace sampling (HSS) with gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The optimized HSS-GC and HSS-GC/MS methods were validated according to the parameters. The limit of quantification (LOQ) values for MeOH analyzed by HSS-GC/MS and HSS-GC were 0.50-0.56 and 1.97 mg/L, and the corresponding values for IPA were 0.14-0.21 and 1.51 mg/L, respectively. Recoveries were determined by spiking sample matrices, such as vinegar and tea. MeOH and IPA showed excellent recoveries of 93.80-107.60% and 93.92-104.32% with corresponding precisions of 0.51-7.38% and 0.90-7.70%, respectively. Compared to solid-phase microextraction-GC/MS and HSS-GC, the HSS-GC/MS method showed outstanding values for limit of detection and LOQ with improved precision and accuracy. This HSS-GC/MS method was successfully used to monitor residual solvents in 100 food and functional food products.

Effects of different sleeping postures on intraocular pressure and ocular perfusion pressure in healthy young subjects.

OBJECTIVE: To investigate the effects of different sleeping positions of head and body on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in healthy, young subjects. DESIGN: Prospective, comparative case series. PARTICIPANTS: Twenty healthy young Korean subjects. METHODS: We measured IOP and blood pressure (BP) with the subjects seated and recumbent, including supine, right lateral decubitus, left lateral decubitus, prone with right head turn, and prone with left head turn positions. We measured IOP using an Icare tonometer in both eyes 5 minutes after assuming each position in a randomized sequence. We calculated the OPP using the formulas based on the mean BP adjusted for the height of the eye over the heart. The eye on the lower side in the lateral decubitus or prone with head turn position was termed the dependent eye. MAIN OUTCOME MEASURES: Difference in IOP and OPP of the dependent and nondependent eyes during changes of sleeping positions of body and head. RESULTS: Mean IOP of right and left eyes while sitting was significantly lower than that measured in each recumbent position (all P<0.001). The OPPs in both eyes were significantly higher in all recumbent positions than in a sitting position (all P<0.001). Mean IOP of the dependent eyes was higher than that of the nondependent eyes in the lateral decubitus positions and in the prone positions with head turns (all P<0.001). No significant intereye difference in OPP was found for any position. Among IOPs measured in the recumbent positions, mean IOP of the dependent eye in the lateral decubitus position or in the prone position with head turn was significantly higher than that of the ipsilateral eye in the supine position (all P<0.0001). CONCLUSIONS: All sleeping positions of head and body resulted in an elevation of IOP and an increase in the calculated OPP compared with the sitting position in healthy, young subjects. The postural change from supine to lateral decubitus or prone with head turn position increased the IOP of the dependent eyes without significant alteration in OPP in healthy awake subjects. Further research is needed under nocturnal conditions in a sleep laboratory. FINANCIAL DISCLOSURES: The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Ability of cirrus high-definition spectral-domain optical coherence tomography clock-hour, deviation, and thickness maps in detecting photographic retinal nerve fiber layer abnormalities.

PURPOSE: To investigate the ability of clock-hour, deviation, and thickness maps of Cirrus high-definition spectral-domain optical coherence tomography (HD-OCT) in detecting retinal nerve fiber layer (RNFL) defects identified in red-free fundus photographs in eyes with early glaucoma (mean deviation >-6.0 dB). DESIGN: Cross-sectional study. PARTICIPANTS: Two hundred ninety-five eyes with glaucomatous RNFL defects with clear margins observed in red-free fundus photographs and 200 age-, sex-, and refractive error-matched healthy eyes were enrolled. METHODS: The width and location of RNFL defects were evaluated by using the red-free fundus photograph. When a RNFL defect detected by red-free fundus photograph did not present as (1) yellow/red codes in the clock-hour map, (2) yellow/red pixels in the deviation map, or (3) blue/black areas in the thickness map, the event was classified as a misidentification of a photographic RNFL defect by Cirrus HD-OCT. In healthy eyes, the presence of false-positive RNFL color codes of Cirrus HD-OCT maps was investigated. MAIN OUTCOME MEASURES: The prevalence of and factors associated with the (1) misidentification of photographic RNFL defects by Cirrus HD-OCT in eyes with glaucoma and (2) false-positive RNFL color codes of Cirrus HD-OCT maps in healthy eyes were assessed. RESULTS: Among the 295 red-free fundus photographic RNFL defects from 295 eyes with glaucoma, 83 (28.1%), 27 (9.2%), and 0 (0%) defects were misidentified in the clock-hour, deviation, and thickness maps of Cirrus HD-OCT, respectively. Fifty-six defects (19.0%) were misidentified only in the clock-hour map and 27 (9.2%) in both the clock-hour and deviation maps. The misidentification of photographic RNFL defects by Cirrus HD-OCT was associated with a narrower width and a temporal location of RNFL defects (P<0.05). Among the 200 healthy eyes, 25 (12.5%), 30 (15.0%), and 12 (6.0%) eyes had false-positive RNFL color codes in clock-hour, deviation, and thickness maps of Cirrus HD-OCT, respectively. CONCLUSIONS: Among the clock-hour, deviation, and thickness maps obtained with Cirrus HD-OCT, the thickness map showed the best diagnostic ability in detecting photographic RNFL defects. The RNFL thickness map may be a useful tool for the detection of RNFL defects in eyes with early glaucoma.

Evaluation of polycyclic aromatic hydrocarbons content of herbal medicine products in Korea by HPLC-FLD.

The objective of this study was to quantify four polycyclic aromatic hydrocarbons (PAH4) in herbal medicine products in Korea. The PAH4 (benzo[a]anthracene, benzo[b]fluoranthene, chrysene, and benzo[a]pyrene) were analyzed in 70 popularly used herbal medicine products without containing essential oil and containing essential oil matrices, using 3-methylcholanthrene as the internal standard. Ultrasonication and liquid-liquid extraction were followed by HPLC-FLD analysis. Satisfactory linearity (R 2 = 0.99), limit of detection (0.05-0.18 µg/kg), limit of quantification (0.14-0.54 µg/kg), recovery (85.72-112.18%), and precision (0.22-2.90%) of PAH4 were acquired. PAH contamination was detected in all herbal medicine products without containing essential oil and containing essential oil matrices types. In 44 samples of herbal medicine products, all PAH4 were detected, and in two samples of the other herbal medicine products, only benzo[b]fluoranthene was detected. The average concentration of PAH4 was 3.88 µg/kg. The validated analytical method was used for preventing human health risks related to the consumption of herbal medicines.

Longitudinal Changes in Peripapillary and Macular Vessel Densities in Glaucomatous Eyes With a Single-Hemifield Retinal Nerve Fiber Layer Defect.

PRCIS: The peripapillary vessel density decreased significantly in the affected hemiretina compared with that in the intact hemiretina in glaucomatous eyes with a single-hemifield retinal nerve fiber layer defect. PURPOSE: To evaluate the difference in the change rates of peripapillary vessel density (pVD) and macular vessel density (mVD) measured using optical coherence tomography angiography (OCTA) in glaucomatous eyes with a single-hemifield retinal nerve fiber layer (RNFL) defect. MATERIALS AND METHODS: We performed a retrospective, longitudinal study of 25 patients with glaucoma who were followed up for at least 3 years, with a minimum of 4 visits after baseline OCTA. At each visit, all participants underwent OCTA examination, and the pVD, mVD were measured by removing the large vessels. Changes in the pVD, mVD, peripapillary RNFL thickness (pRNFLT), and macular ganglion cell inner plexiform layer thickness were investigated in the affected and intact hemispheres, and the differences between the 2 hemispheres were compared. RESULTS: In the affected hemiretina, the pVD, mVD, pRNFLT, and mCGIPLT were reduced than that in the intact hemiretina (all, P < 0.001). The changes in pVD and mVD were statistically significant at the 2-year and 3-year follow-ups in the affected hemifield (all, P <0.05). However, pVD and mVD did not show statistically significant changes in the intact hemiretina throughout the follow-up visits. Although the pRNFLT decreased significantly at the 3-year follow-up, the macular ganglion cell inner plexiform layer thickness showed no statistical change at any follow-up visit. Compared with the intact hemisphere, pVD was the only parameter that showed significant changes throughout the follow-up period. CONCLUSION: Although pVD and mVD decreased in the affected hemiretina, the reduction in pVD was significant compared with that in the intact hemiretina.

Astigmatism and optical coherence tomography measurements.

BACKGROUND: To evaluate the effect of astigmatism change on measurement of retinal nerve fiber layer (RNFL) and macular thickness by Cirrus HD spectral-domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec, Dublin, CA, USA). METHODS: A total of 30 right eyes from 30 healthy young subjects underwent RNFL and macular thickness measurements using Cirrus HD OCT. Measurements were performed at the baseline state and induced with-the-rule (WTR) and against-the-rule (ATR) astigmatism states by wearing toric soft contact lenses (+1.50 -3.25 diopter × 90° and +1.50 -3.25 diopter × 180° respectively). Differences in RNFL and macular thickness between the baseline state and induced astigmatism states were analyzed. RESULTS: Wearing toric soft contact lenses induced a mean 2.92 diopter WTR and 3.18 diopter ATR astigmatism respectively. After signal strength change adjustment, RNFL thicknesses of average, superior quadrant, 12 and 6 o'clock hour sectors decreased after induction of a WTR astigmatism (mean difference range, 1.58 to 6.88 µm); RNFL thicknesses of average, nasal, temporal quadrants, 2, 3, and 9 o'clock hour sectors decreased after induction of an ATR astigmatism (mean difference range, 0.75 to 5.11 µm) (all P values <0.05). Macular thickness was not significantly affected by astigmatism changes (all P values ≥ 0.250). CONCLUSION: Although the amount of change was not substantial, RNFL thickness measured by Cirrus HD OCT was affected by astigmatism changes induced by contact lenses. It may be warranted to consider the effect of astigmatism on RNFL thickness measured by OCT in eyes with higher degrees of astigmatism.

Evaluation of a GC-MS method for benzyl chloride content in processed food, meats, and marine products distributed in Korea.

Benzyl chloride is a harmful chemical that contaminates air, water, and food. A static headspace GC-MS method for determining benzyl chloride in food was developed and validated. Two food matrices (fat/oil and chicken) were used for method validation. Sample preparation involved ultrasonication extraction and purification (syringe filtration). Linearity (R 2) was > 0.99, accuracy ranged from 86.91% to 110%, the limit of detection was 0.04-0.17 mg/kg, and the limit of quantification was 0.13-0.52 mg/kg. Recovery varied from 88.19% to 111.77%, and precision ranged from 0.10% to 1.17% in intraday and interday analyses. Among 102 food items (oils, fats, meat, marine, and egg products) distributed in Korea, benzyl chloride was only detected in six of the marine products. The validated analytical method can be used for routine monitoring of benzyl chloride residues in food and thereby prevent the human health risks associated with the consumption of food contaminated with this chemical.

Development of freshness indicator for monitoring chicken breast quality and freshness during storage.

An indicator for freshness and quality measurement was utilized to perceive changes in freshness quality while storing chicken breasts. Visible color changes of the indicator shows spoilage and freshness of the packaged products. In addition, changes in pH, volatile basic nitrogen (VBN), and Pseudomonas spp. were monitored. The color change sensor (ΔE) reflected the headspace pH during the chicken breasts' packaging process. After storing chicken breast at 20 °C for 24 h, the color change (ΔE) of the indicator for freshness and quality measurement changed. The color change (ΔE) values were correlated with quality characteristics such as sensory, microbiological, and chemical properties that were popularly used to settle the freshness of chicken breast. In conclusion, the results showed that the indicator for freshness and quality measurement was useful in settling the shelf life of chicken breast products by physicochemical changes and monitoring microbial safety. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01034-x.

Risk Assessment and Determination of Heavy Metals in Home Meal Replacement Products by Using Inductively Coupled Plasma Mass Spectrometry and Direct Mercury Analyzer.

This study quantified six heavy metals (Pb, Cd, As, Sn, Hg, and Me-Hg) in home meal replacement products. Satisfactory linearity (R2 > 0.99), recovery (80.65-118.02%), limits of detection (0.02-2.81 µg/kg), limits of quantification (0.05-8.51 µg/kg), accuracy (80.49-119.87%), precision (0.26-14.93%), standard uncertainty (0.082-0.321%) and relative standard uncertainty (0.084-0.320%) of the six heavy metals were obtained. The average concentration of the six heavy metals was 8.87 µg/kg. Heavy metal concentrations were converted to food intake data of 0.009 µg/kg to recalculate the 95th percentile food intake data (g/day) of individual heavy metals. These were then divided by age group to evaluate the average exposure to heavy metals and determine the 95th percentile of exposure from daily intake and for the whole population, of home meal replacement products. The chronic daily intake amount of six heavy metals was 1.60 × 10-2 µg/kg/day. Based on total chronic daily intake values, the risk and margin of exposure of each of the heavy metals was 9.13 × 107, demonstrating that intake associated with home meal replacement products is negligible.