This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.
Dizziness ; Eyeglasses* ; Glass ; Humans ; Korea ; Outpatients ; Visual Acuity

This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.
Dizziness ; Eyeglasses* ; Glass ; Humans ; Korea ; Outpatients ; Visual Acuity

The effects of different luminance levels and light sources to emmetropization in the chick were investigaed. One-day-old, forty chicks were reared under condition of unilateral visual deprivation with translucent goggle. Under normal light cycles (12-h light/12-h dark), three kinds of luminance levels and two light sources (incandescent lamp vs fluorescent lamp) were used. Three weeks after hatching, refractive error, axial length, equator diameter and corneal diameter of the eyes were measured. The deprived eyes exhibited severe myopia of -11.94 diopters (p<0.001) and refractive changes were mainly related with axial elongations. Refractive error of 1000 lux group was less myopic than 2000 lux group (p<0.05). The fellow eyes didn't show significant difference between groups. No significant changes were noted between different light source groups. The experiment suggests that different degrees of illumination under normal light/dark environment can cause different refractive changes; More studies will be needed to show that the ideal luminance condition for emmetropization in our enviroment be present.
Lighting* ; Myopia ; Photoperiod ; Refractive Errors*

OBJECTIVE: In pectus excavatum patients, Nuss procedure provides excellent cosmetic results, but it cause hypoxemia and hypercarbia by the reduction of alveolar ventilation due to severe thorax expansion and pain after operation. This study was designed to evaluate the effect of different oxygen flow rates via a nasal cannula in recovery room after correction of pectus excavatum by Nuss procedure. METHODS: Forty patients (3–12 years old) undergoing pectus excavatum repair were randomly assigned and divided into two groups. Patients were given 200 mL/kg/min flow of 100% oxygen (group 1) and 100 mL/kg/min flow of oxygen (group 2) via nasal cannula in the recovery room. Arterial blood gas analysis and peripheral oxygen saturation were measured at arrival and after 5, 10, 15, and 30 minutes in the recovery room. RESULTS: In group 1 compared with group 2, decrease of PaCO2 (partial pressure of CO2 in arterial blood) accumulation was observed in 5, 10, and 15 minutes. Arterial oxygen pressure (PaO2) difference was not significant between the group. But, in comparison within groups, PaO2 level was significantly higher at 5, 10, 15, and 30 minutes than just after arrival at the recovery room. In both group, heart rate and systolic blood pressure were no significant difference. CONCLUSION: We recommend that 200 mL/kg/min flow of 100% oxygen should be administered to patients who were taken Nuss procedure for prevention of hypoxemia and hypercarbia in recovery rooms.
Anoxia ; Blood Gas Analysis ; Blood Pressure ; Catheters* ; Funnel Chest* ; Heart Rate ; Humans ; Oxygen* ; Recovery Room* ; Thorax ; Ventilation

Background: The purpose of this study was to investigate the demographic factors and radiological characteristics of lesser trochanter splitting (LTS) irreducible intertrochanteric fractures and to report the clinical results of patients who underwent open reduction and internal fixation using dynamic hip screws (DHS). Methods: Inclusion criteria were as follows: AO/Orthopedic Trauma Association type 31A1.2, a fracture line originating from the outside of the greater trochanter that passes through the lesser trochanter, and patients who were followed up for more than 1 year with a confirmed presence or absence of bone union. A total of 13 cases were identified, accounting for 3.1% (13/416 intertrochanteric fractures). Patients were classified according to posterior sagging of the distal shaft fragment relative to the headneck fragment (posterior sagging group, 6; non-sagging group, 7). Demographic data, comorbidities, injury mechanism, type of anesthesia, operation time, blood loss, tip-apex distance, reduction quality, leg length discrepancy (> 5 mm), long lesser trochanter sign, postoperative complications, and presence of bony union were obtained by reviewing medical records and radiological findings. Results: The mean age of the patients was 50.4 ± 10.4 years, and 12 were men. Except for 1 case (slip down), all were induced by high-energy trauma. According to the grade of reduction quality, 5 cases (38.5%) had good reduction quality and 8 cases (61.5%) had acceptable reduction quality. There were no postoperative complications, and bony union was observed in all cases. The long lesser trochanter sign was observed in 5 cases (38.5%) and leg length discrepancy greater than 5 mm was not observed. Compared with the non-sagging group, the posterior sagging group had more head-neck fragments containing more than 1/2 of the lesser trochanter length, longer operation time, and more blood loss (p < 0.05). Compared to the non-sagging group, the posterior sagging group had worse reduction quality and more long lesser trochanter signs (p < 0.05). Conclusions Open reduction and internal fixation using DHS for the LTS irreducible intertrochanteric fractures can achieve good clinical and radiological outcomes. However, in the posterior sagging type, reduction can be more difficult with a longer operation time and higher likelihood of blood loss.

Background: This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS). Methods: Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied. Results: With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions. Conclusions The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.

Background: This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS). Methods: Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied. Results: With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions. Conclusions The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.

Background: This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS). Methods: Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied. Results: With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions. Conclusions The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.

Background: This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS). Methods: Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied. Results: With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions. Conclusions The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.

BACKGROUND: Intravenous palonosetron-HCl, a second-generation antagonist of selective serotonin type 3 (5-HT3) receptors, can prevent chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV). 5-HT3 receptors are abundant in the lower brainstem and the substantia gelatinosa of the spinal cord, which provides a theoretical rationale for neuraxial administration of 5-HT3 receptor antagonists for CINV, PONV, and opioid-induced nausea and vomiting. However, there are no reports of neuraxial administration of palonosetron-HCl. Before neuraxial administration of a drug is accepted for clinical use, its safety must be proven. This study was conducted to determine whether neuraxial administration of palonosetron-HCl produces neurologic injury. METHODS: Male Sprague-Dawley rats under general anesthesia were catheterized intrathecally and the catheter tip was advanced caudally to the L1 vertebra. After 7 days, 20 µl of normal saline (N group, n = 6) or 20 µl (1 µg) of palonosetron-HCl (P group, n = 6) were injected intrathecally once per day for 2 weeks. Neurotoxic changes were evaluated by light microscopy (LM) and electron microscopy (EM) of the spinal cord. Behavioral changes were also evaluated in both groups. RESULTS: One of the N group rats and three of the P group rats demonstrated abnormal behavior during intrathecal drug injection, but otherwise their behavior was normal. The spinal cords of the N group did not have any abnormal findings by LM or EM. The spinal cords of the P group had multiple vacuoles in the white matter by LM, especially in the dorsal funiculus, and EM revealed myelin, axonal, and mitochondrial swelling. CONCLUSIONS: Results suggest that chronic intrathecal administration of palonosetron-HCl produced microscopic morphologic changes in the spinal cords of rats.
Anesthesia, General ; Animals ; Axons ; Brain Stem ; Catheters ; Humans ; Injections, Spinal ; Male ; Microscopy ; Microscopy, Electron ; Mitochondrial Swelling ; Myelin Sheath ; Nausea ; Postoperative Nausea and Vomiting ; Rats* ; Rats, Sprague-Dawley ; Receptors, Serotonin, 5-HT3 ; Serotonin ; Spinal Cord* ; Spine ; Substantia Gelatinosa ; Vacuoles ; Vomiting ; White Matter