PURPOSE: To compare the long-term prognosis of laser in situ keratomileusis (LASIK) and surface ablation in moderate to high myopia. METHODS: A retrospective study including 87 eyes of 44 myopic patients treated with LASIK or surface ablation from 1995 to 2005 was performed. Follow-up visits were performed at 3 months, 1 year, 5 years, and 8 years. All treated eyes were divided into 2 groups according to preoperative spherical equivalent (SE)- moderate myopia (<-6.0 diopters [D]) and high myopia (≥-6.0 D). The main outcome measures were postoperative uncorrected visual acuity (UCVA), best corrected visual acuity, SE, mean keratometry, safety index, efficacy index, predictability, and complications. RESULTS: Mean SE was -7.05 ± 2.49 D in the LASIK group and -5.25 ± 1.23 D in the surface ablation group. The 10-year SE was -1.78 ± 1.22 D in the LASIK group and -1.35 ± 1.09 D in the surface ablation group, and there was no statistical difference between the 2 groups. At 10 years postoperatively, UCVA was log MAR 0.155 ± 0.161 in the LASIK group and log MAR 0.095 ± 0.140 in the surface ablation group. There were no significant differences in postoperative mean SE, safety index, efficacy index, or complications between the LASIK and surface ablation group at 10 years. CONCLUSIONS: This 10-year follow-up study shows that LASIK and surface ablation for moderate to high myopia have no statistical differences in mean SE, safety index, efficacy index, or complications.
Follow-Up Studies ; Humans ; Keratomileusis, Laser In Situ* ; Myopia* ; Outcome Assessment (Health Care) ; Prognosis ; Retrospective Studies ; Visual Acuity

BACKGROUND: Administering extracorporeal membrane oxygenation (ECMO) to critically ill patients with acute respiratory distress syndrome has substantially increased over the last decade, however administering ECMO to patients with hematologic malignancies may carry a particularly high risk. Here, we report the clinical outcomes of patients with hematologic malignancies and severe acute respiratory failure who were treated with ECMO. METHODS: We performed a retrospective review of the medical records of patients with hematologic malignancies and severe acute respiratory failure who were treated with ECMO at the medical intensive care unit of a tertiary referral hospital between March 2010 and April 2015. RESULTS: A total of 15 patients (9 men; median age 45 years) with hematologic malignancies and severe acute respiratory failure received ECMO therapy during the study period. The median values of the Acute Physiology and Chronic Health Evaluation II score, Murray Lung Injury Score, and Respiratory Extracorporeal Membrane Oxygenation Survival Prediction Score were 29, 3.3, and -2, respectively. Seven patients received venovenous ECMO, whereas 8 patients received venoarterial ECMO. The median ECMO duration was 2 days. Successful weaning of ECMO was achieved in 3 patients. Hemorrhage complications developed in 4 patients (1 pulmonary hemorrhage, 1 intracranial hemorrhage, and 2 cases of gastrointestinal bleeding). The longest period of patient survival was 59 days after ECMO initiation. No significant differences in survival were noted between venovenous and venoarterial ECMO groups (10.0 vs. 10.5 days; p = 0.56). CONCLUSIONS: Patients with hematologic malignancies and severe acute respiratory failure demonstrate poor outcomes after ECMO treatment. Careful and appropriate selection of candidates for ECMO in these patients is necessary.
Adult* ; APACHE ; Critical Illness ; Extracorporeal Membrane Oxygenation* ; Hematologic Neoplasms* ; Hemorrhage ; Humans ; Intensive Care Units ; Intracranial Hemorrhages ; Lung Injury ; Male ; Medical Records ; Respiratory Distress Syndrome, Adult ; Respiratory Insufficiency* ; Retrospective Studies ; Tertiary Care Centers ; Weaning

PURPOSE: To evaluate the effects of preoperative and postoperative parameters, particularly anterior chamber depth, on corneal endothelial cell loss during cataract surgery. METHODS: Eighty-two eyes of 82 patients who underwent cataract surgery by the same surgeon using the same technique were selected for the present study. Various preoperative and postoperative parameters including age, anterior chamber depth, duration and power of phacoemulsification, preoperative endothelial cell density, coefficient of variation, hexagonality, and grade of nucleosclerosis were evaluated. Endothelial cell densities were recorded preoperatively and at two months postoperatively using a noncontact specular microscope. RESULTS: After two months, the mean central endothelial cell loss in all eyes was 8.77%. Among the pre- and post-operative parameters, patient' age, anterior chamber depth, duration, power, and energy of phacoemulsification and grade of nucleosclerosis showed significant correlation with endothelial cell loss. Stepwise multiple linear regression analysis identified age, nucleosclerosis, anterior chamber depth, and phacoemulsification time as independent predictors for endothelial cell loss. CONCLUSIONS: The risk of endothelial cell loss increased with increases in patient' age, nucleosclerosis, and phacoemulsification time. However, eyes with a deep anterior chamber showed a significantly lower risk of endothelial cell loss.
Anterior Chamber ; Cataract ; Cornea ; Corneal Endothelial Cell Loss ; Endothelial Cells ; Eye ; Humans ; Linear Models ; Phacoemulsification

BACKGROUND: The aim of the study was to evaluate the biochemical effects of recombinant human thyroid stimulating hormone (rhTSH) as an adjunct to radioiodine (RI) treatment of a differentiated thyroid carcinoma (DTC). We retrospectively reviewed the clinical response rates of DTC patients treated with RI after thyroid hormone withdrawal and compared with those after rhTSH stimulation. METHOD: We included the patients treated with RI for locally recurrent DTC from February 1, 2002 to August 31, 2005 and followed with diagnostic studies at our hospital. Forty totally (or near totally) thyroidectomized adults were included in this study. Nine patients underwent RI treatment after rhTSH stimulation while euthyoid on L-thyroxine (LT4), and 31 patients were treated with RI after thyroid hormone withdrawal. The clinical response was defined as >25% decrease in serum thyroglobulin (Tg) level on LT4 3 months after the RI treatment. RESULTS: In each group, serum Tg levels were significantly decreased 3 months after the RI treatment. And we found that 77.8 and 71.0% of those prepared by rhTSH and LT4 withdrawal, respectively, had clinical responses 3 months after the RI treatment by our criteria and there was no significant difference in response rates between two groups (P=0.238). CONCLUSIONS: Given the biases that exist in retrospective studies, at the current time we cannot recommend the routine use of rhTSH to prepare RI treatment of DTC. However, our study provided preliminary evidence that rhTSH effectively aided RI treatment of DTC at least to an equivalent degree as LT4 withdrawal.
Adult ; Bias (Epidemiology) ; Humans* ; Retrospective Studies* ; Thyroglobulin ; Thyroid Gland* ; Thyroid Neoplasms* ; Thyrotropin ; Thyrotropin Alfa ; Thyroxine

BACKGROUND: The aim of the study was to evaluate the biochemical effects of recombinant human thyroid stimulating hormone (rhTSH) as an adjunct to radioiodine (RI) treatment of a differentiated thyroid carcinoma (DTC). We retrospectively reviewed the clinical response rates of DTC patients treated with RI after thyroid hormone withdrawal and compared with those after rhTSH stimulation. METHOD: We included the patients treated with RI for locally recurrent DTC from February 1, 2002 to August 31, 2005 and followed with diagnostic studies at our hospital. Forty totally (or near totally) thyroidectomized adults were included in this study. Nine patients underwent RI treatment after rhTSH stimulation while euthyoid on L-thyroxine (LT4), and 31 patients were treated with RI after thyroid hormone withdrawal. The clinical response was defined as >25% decrease in serum thyroglobulin (Tg) level on LT4 3 months after the RI treatment. RESULTS: In each group, serum Tg levels were significantly decreased 3 months after the RI treatment. And we found that 77.8 and 71.0% of those prepared by rhTSH and LT4 withdrawal, respectively, had clinical responses 3 months after the RI treatment by our criteria and there was no significant difference in response rates between two groups (P=0.238). CONCLUSIONS: Given the biases that exist in retrospective studies, at the current time we cannot recommend the routine use of rhTSH to prepare RI treatment of DTC. However, our study provided preliminary evidence that rhTSH effectively aided RI treatment of DTC at least to an equivalent degree as LT4 withdrawal.
Adult ; Bias (Epidemiology) ; Humans* ; Retrospective Studies* ; Thyroglobulin ; Thyroid Gland* ; Thyroid Neoplasms* ; Thyrotropin ; Thyrotropin Alfa ; Thyroxine

PURPOSE: To evaluate the effect of clear corneal incisional size on astigmatism during cataract surgery. METHODS: Randomized prospective study of 78 patients (108 eyes) who had received cataract surgery for a corneal astigmatism over against-the-rule (ATR) 1.0 Diopter (D) was performed. The eyes were checked by corneal topography and autorefractor preoperatively and one week, one month, two months, and six months postoperative. Group 1 included patients who received an inserted foldable intraocular lens (IOL) through a 2.8 mm incision, and Group 2 included patients who underwent IOL implantation through a corneal incision enlarged to 4 mm. RESULTS: Postoperative visual acuity showed a better visual acuity in Group 2 at both one week postoperatively (0.598+/-0.352 vs., 0.713+/-0.345, for Groups 1 and 2, respectively, p=0.046) and one month postoperatively (0.604+/-0.237 vs., 0.791+/-0.242, respectively, p=.043). There were no statistically significant differences between the groups after two and six months (p=.135, .087). Postoperative astigmatism measured by corneal topopgraphy showed 1.62+/-0.44D and, 0.94+/-0.30D for groups 1 and 2 respectively, (P=.045) at 2 months, and 1.73+/-0.45 D and, 0.92+/-0.34 D (P=.042) at six months. These results showed a statistically significant amount of residual astigmatism in Group 2. Autorefractor measurements showed similar results. There were no complications, such as wound leakage, resulting from the increased incision size. CONCLUSIONS: Widening of the incision during cataract surgery can reduce corneal astigmatism without significant complications.
Astigmatism ; Cataract ; Corneal Topography ; Eye ; Humans ; Lenses, Intraocular ; Prospective Studies ; Visual Acuity

PURPOSE: The purpose of this study was to propose finite element (FE) modeling methods for predicting stress distributions on teeth and mandible under chewing action. MATERIALS AND METHODS: For FE model generation, CT images of skull were translated into 3D FE models, and static analysis was performed considering linear material behaviors and nonlinear geometrical effect. To find out proper boundary and loading conditions, parametric studies were performed with various areas and directions of restraints and loading. The loading directions are prescribed to be same as direction of masseter muscle, which was referred from anatomy chart and CT image. From the analysis, strain and stress distributions of teeth and mandible were obtained and compared with experimental data for model validation. RESULTS: As a result of FE analysis, the optimized boundary condition was chosen such that 8 teeth were fixed in all directions and condyloid process was fixed in all directions except for forward and backward directions. Also, fixing a part of mandible in a lateral direction, where medial pterygoid muscle was attached, gave the more proper analytical results. Loading was prescribed in a same direction as masseter muscle. The tendency of strain distributions between the teeth predicted from the proposed model were compared with experimental results and showed good agreements. CONCLUSION: This study proposes cost efficient FE modeling method for predicting stress distributions on teeth and mandible under chewing action. The proposed modeling method is validated with experimental data and can further be used to evaluate structural safety of dental prosthesis.
Dental Prosthesis ; Finite Element Analysis ; Mandible ; Masseter Muscle ; Mastication ; Pterygoid Muscles ; Skull ; Sprains and Strains ; Tooth

OBJECTIVETo analyze the genotype-phenotype correlations in the Hb Constant Spring (HbCS) carriers, and to investigate the effect of HbCS on hematologic parameters.

METHODSComplete blood cell count and hemoglobin electrophoresis analyses were performed in 125 HbCS cases. The α-and β-thalassemia mutations were determined by reverse dot-blotting and Gap-PCR.

RESULTSThe presence of the SEA deletion or Hb Quong Sze (HbQS) with HbCS leads to HbH-CS disease. There was significant difference between HbH-CS and αCSα/-α, HbH-CS and αCSα/αα in the hematological parameters. The genotype of αCSα/-α or αα/αCSα had slight effect on hematological parameters. When the Hb Constant Spring mutation co-existed with heterozygous β-thalassemia, the hematological characteristics of β-thalassemia was presented. Only 57.6% of carriers with HbCS were detected by hemoglobin electrophoresis.

CONCLUSIONThe cases with co-existence of HbCS trait and other α-thalassemia trait, or β-thalassemia trait, showed variation in their red blood cell parameters. For such compound heterozygotes for HbCS and other α- or β-thalassaemia mutations, which were usually misdiagnosed in clinical screening by hemoglobin electrophoresis, accurate diagnose can be made by molecular diagnosis.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Genotype ; Hemoglobins ; genetics ; Hemoglobins, Abnormal ; genetics ; Heterozygote ; Humans ; Infant ; Male ; Middle Aged ; Phenotype ; Young Adult ; alpha-Thalassemia ; genetics ; beta-Thalassemia ; genetics

Aspiration of foreign bodies into tracheobronchial tree is more common in children than in adults. Foreign bodies in airway commonly occur by accident, and in most cases they get removed without delay. Small foreign bodies that lodge in the peripheral airway are often asymptomatic initially and can result in respiratory symptoms several years later. Although foreign body aspiration is frequently suspected in children with acute or recurrent pulmonary symptoms, it is rarely considered in adults, unless a clear history of an aspiration event can be obtained. We have experienced and studied a case of occult aspiration of a shrimp which had been lodged for a long period.
Adult ; Bronchi* ; Bronchoscopy* ; Child ; Foreign Bodies* ; Humans

BACKGROUND: Acute Respiratory failure which is developed after extubation in the weaning process from mechanical ventilation is an important cause of weaning failure. Once it was developed, endotracheal reintubation has been done for respiratory support. Noninvasive Positive Pressure Ventilation (NIPPV) has been used in the management of acute or chronic respiratory failure, as an alternative to endotracheal intubation, using via nasal or facial mask. In this study, we evaluated the usefulness of NIPPV as an alternative method of reintubation in paients who developed acute respiratory failure after extubation. METHOD: We retrospectively analyzed thirty one patients (eighteen males and thirteen females, mean ages 63+/-13.2 years) who were developed acute respiratory failure within forty eight hours after extubation, or were extubated unintentionally at medical intensive care unit(MICU) of Asan Medical Center. NIPPV was applied to the patients. Ventilatory mode of NIPPV, level of ventilatory support and inspiratory oxygen concentration were adjusted according to the patient condition and results of blood gas analysis by the attending doctors at MICU. NIPPV was completely weaned when the patients maintained stable clinical condition under 8 cmH2O of pressure support level. Weaning success was defined as maintenance of stable spontaneous breathing more than forty eight hours after discontinuation of NIPPV. Respiratory rate, heart rate, arterial blood gas analysis, level of pressure support, and level of PEEP were monitored just before extubation, at thirty minutes, six hours, twenty four hours after initiation of NIPPV. They were also measured at just before weaning from NIPPV in success group, and just before reintubation in failure group. RESULTS: 1) NIPPV was successfully applied to thirty-one patients of thirty-two trials and one patient could not tolerated NIPPV longer than thirty minutes. Endotracheal reintubation was successfully obviated in fourteen patients (45%) among them. 2) There was no difference in age, sex, APACHE III score on admission at MICU, duration of intubation, interval from extubation to initiation of NIPPV, baseline heart rate, respiratory rate, arterial blood gas, and PaO2/FiO2 between the success and the failure group. 3) Heart rate and respiration rate were significantly decreased with increase SaO2 after thirty minutes of NIPPV in both groups (p<0.05). Ho wever, in the patients of failure group, heart rate and respiratory rate were increased again with decrease in SaO2 leading to endotracheal reintubation. 4) The success rate of NIPPV treatment was significantly higher in the patients with COPD compared to other diseases (62% vs 39%) (p=0.007). 6) The causes of failure were deterioration of arterial blood gas without aggravation of underlying disease (n=9), aggravation of undelying disease (n=5), mask intolerance (n=2), and retained airway secretion (n=1). CONCLUSION: NIPPV would be a useful therapeutic alternative which can avoid reintubation in patient who developed acute respiratory failure after extubation.
APACHE ; Blood Gas Analysis ; Chungcheongnam-do ; Female ; Heart Rate ; Humans ; Critical Care ; Intubation ; Intubation, Intratracheal ; Male ; Masks ; Oxygen ; Positive-Pressure Respiration* ; Pulmonary Disease, Chronic Obstructive ; Respiration ; Respiration, Artificial ; Respiratory Insufficiency* ; Respiratory Rate ; Retrospective Studies ; Weaning