Objective:To study the illumination for distance vision evaluation of the pilots wearing night vision goggles (NVGs).Methods:The distance vision was tested by circular visual acuity chart for flying personnel 5 m apart from subjects. The Illuminance on the surface of chart was set 300 lx for naked eye and 1×10 -1 lx and 1×10 -3 lx for NVG aided eyes. The naked and NVG distance visions of 15 healthy male volunteers were tested under all illuminations. The differences of NVG distance vision were compared between the illuminations of 1×10 -1 lx and 1×10 -3 lx to determine the proper level for evaluation. The naked and NVG distance visions of 20 male pilots were tested to verify the feasibility and necessity of the test, but NVG tests were only at 1×10 -1 lx level. Results:Volunteers′ left distance vision was 0.67±0.39, the right was 0.67±0.38 and the binocular was 0.80±0.40. Their NVG distance vision under 1×10 -1 lx was 0.53±0.22, 0.59±0.25 and 0.63±0.24 respectively, comparing with the vision of 0.30±0.11, 0.34±0.11 and 0.36±0.11 under 1×10 -3 lx. The difference showed statistical significance ( P<0.05). In verification test, the left, right and binocular NVG distance vision of 20 pilots under 1×10 -1 lx was 0.63±0.16, 0.64±0.14 and 0.73±0.12 respectively, comparing with their left, right and binocular naked vision of 1.12±0.32, 1.08±0.37, and 1.37±0.37 respectively. Conclusions:The tests indicated that 1×10 -1 lx would be the appropriate illumination level for pilot′s NVG distance vision evaluation. And it is necessary to evaluate pilot′s NVG distance vision before night flight mission.

Objective:To study the illumination for distance vision evaluation of the pilots wearing night vision goggles (NVGs).Methods:The distance vision was tested by circular visual acuity chart for flying personnel 5 m apart from subjects. The Illuminance on the surface of chart was set 300 lx for naked eye and 1×10 -1 lx and 1×10 -3 lx for NVG aided eyes. The naked and NVG distance visions of 15 healthy male volunteers were tested under all illuminations. The differences of NVG distance vision were compared between the illuminations of 1×10 -1 lx and 1×10 -3 lx to determine the proper level for evaluation. The naked and NVG distance visions of 20 male pilots were tested to verify the feasibility and necessity of the test, but NVG tests were only at 1×10 -1 lx level. Results:Volunteers′ left distance vision was 0.67±0.39, the right was 0.67±0.38 and the binocular was 0.80±0.40. Their NVG distance vision under 1×10 -1 lx was 0.53±0.22, 0.59±0.25 and 0.63±0.24 respectively, comparing with the vision of 0.30±0.11, 0.34±0.11 and 0.36±0.11 under 1×10 -3 lx. The difference showed statistical significance ( P<0.05). In verification test, the left, right and binocular NVG distance vision of 20 pilots under 1×10 -1 lx was 0.63±0.16, 0.64±0.14 and 0.73±0.12 respectively, comparing with their left, right and binocular naked vision of 1.12±0.32, 1.08±0.37, and 1.37±0.37 respectively. Conclusions:The tests indicated that 1×10 -1 lx would be the appropriate illumination level for pilot′s NVG distance vision evaluation. And it is necessary to evaluate pilot′s NVG distance vision before night flight mission.

Objective    To analyze the risk factors of anastomotic leakage after esophagectomy. Methods    The clinical data of 1 328 patients with esophageal cancer, who underwent esophagectomy in the First Affiliated Hospital of Henan University of Science and Technology from January 2010 to December 2016, were retrospectively analyzed. There were 726 males and 602 females, at an average age of 67.2±14.1 years. According to whether there was anastomotic leakage after operation, patients were divided into two groups: an anastomotic leakage group (167 patients) and a non-anastomotic leakage group (1 161 patients). Univariate and multivariate logistic regression analysis was used to identify related risk factors of anastomotic leakage after operation. Results     The incidence of postoperative anastomotic leakage was 12.6% (167/1 328). Univariate analysis showed that body mass index, arrhythmia, chronic obstructive pulmonary disease (COPD), diabetes, preoperative albumin level, preoperative chemotherapy and chemoradiotherapy, lesion location, anastomosis types and postoperative pulmonary infection were associated with statistically significant increase in risk of cervical anastomotic leakage (P<0.05). Logistic regression analysis showed that preoperative COPD, lesion location and postoperative pulmonary infection were independent risk factors of cervical anastomotic leakage after esophagectomy (P<0.05). Conclusion    The occurrence of cervical anastomotic leakage after esophageal cancer is related to many factors. The preoperative COPD, the lesion location and the postoperative pulmonary infection are independent high risk factors. Paying attention to these factors and doing perioperative management can effectively reduce the occurrence of anastomotic leakage.

Objective To detect the dynamic visual acuity ( DVA) before and after vestibular habituation of subjects in order to optimize the DVA assessment criteria .Methods The vestibular function examination system was applied to the detection of static and dynamic visual function in 16 healthy subjects .Results When the speed of left or right swinging was fast enough , DVA before and after vestibular habituation was different .Conclusion Subjects with vestibular habituation can reduce their sensitivity to the vestibular system , the changes in DVA are better than before habituation , and the vestib-ular function adaptability training may have effect on DVA .