应用双通道客观视觉质量分析系统与光线追踪波阵面像差系统分析正常人眼调制传递函数

目的 比较双通道客观视觉质量分析系统(OQASⅡ)与光线追踪波阵面像差系统(iTrace)测量正常人眼调制传递函数(MTF)的一致性,寻找更准确的客观视觉质量评价手段.方法 对比研究.连续收集前往设置在邯郸市永年县东杨庄中心卫生院的邯郸眼病研究检查现场健康受试者进行研究,对排除眼部疾病后的受试者进行散瞳前对比敏感度检查、散瞳后使用OQASⅡ与iTrace测量全眼MTF.比较两者在4.0和6.0 mm瞳孔直径下5、10、15、20、25、30周/度(c/d)空间频率下消除低阶像差影响后的MTF均值,对符合正态分布的两种仪器在不同空间频率的MTF测量值进行配对t检验.绘制Bland-Altman图进行一致性评价,并分别对两种仪器的MTF测量值与最佳矫正视力、不同空间频率下对比敏感度进行Spearman秩相关分析.结果 共有163例(251只眼)患者入选本研究,其中男性81例(139只眼),女性82例(112只眼),年龄30 ～ 60岁,平均(44.1±9.7)岁.在4.0 mm瞳孔直径下iTrace在5、10、15、20、25、30 c/d空间频率下的MTF均值分别为0.730±0.138、0.431 ±0.159、0.262±0.120、0.169 ±0.078、0.118 ±0.053、0.094±0.043,OQASⅡ分别为0.347±0.123、0.162 ±0.086、0.072 ±0.049、0.042±0.033、0.026±0.022、0.017 ±0.022,两种仪器的差异均有统计学意义(t=38.72,28.03,27.32,27.59,29.23,28.96;P ＜0.01);在6.0 mm瞳孔直径下,两种仪器的差异也有统计学意义(t =4.60,3.19,9.34,13.41,16.96,20.24;P ＜0.01).Bland-Altman一致性分析法提示两者一致性较差,但在6.0 mm瞳孔直径两者一致性有所提高.iTrace MTF测量值与最佳矫正视力呈负相关(r=-0.139～-0.165,P＜0.01),部分空间频率MTF值与6 c/d空间频率对比敏感度Log值呈正相关(r=0.163 ～0.175),P＜0.05);OQASⅡMTF值与最佳矫正视力呈负相关(r=0.239 ～0.303,P＜0.01),各空间频率MTF值与3、6、12、18 c/d空间频率对比敏感度Log值均呈正相关(r =0.156～0.398,P＜0.01).结论 iTrace与OQAS在正常人眼MTF测量存在明显差异,瞳孔直径较大时两者差值较小;双通道技术为临床人眼光学质量评估提供了一种新的手段.     

硅油填充眼核磁共振成像与A型超声测量结果比较

目的 观察并探讨核磁共振成像(MRI)用于硅油填充眼眼球视轴测量的可行性及其优缺点.方法 32例32只硅油填充眼纳入本研究.采用MRI横断面T1加权像(T1 WI)、T2加权像(T2WI)检测硅油前后间隙,以脂肪抑制后T2WI成像测量眼球视轴;以角膜顶点至黄斑中心凹距离作为视轴长度,此连线上测量硅油后间隙的厚度.A型超声采取坐位及仰卧位检查,坐位测量眼球视轴长度,改变超声传播速度以修正眼球视轴长度;仰卧位检测硅油后间隙.结果 MRI检测结果显示,硅油在T1WI像中信号较对侧玻璃体高,T2WI像中信号较玻璃体低,加脂肪抑制后硅油信号降低,化学位移伪影减少;受检眼玻璃体腔内均存在不同程度的硅油前后间隙,玻璃体后间隙厚度为(2.47±1.31)mm.A型超声检测结果显示,18只眼可检测到硅油后间隙,占56.25%.MRI、A型超声测量本组患者硅油填充眼视轴长度分别为(23.52±4.67)、(20.57±5.32)mm,两者比较,其差异有统计学意义(t=30.17,P＜0.05).结论 MRI能够用于硅油填充眼视轴测量,并对硅油前后间隙进行观察和测量.

Abstract：

Objective To investigate the feasibility of using magnetic resonance imaging (MRI) to measure the visual axis length in silicone oil filled eyeballs. Methods Thirty-two silicone oil-filled eyes of 32 patients were studied. The ante-silicone oil spaces (ASS) and retro-silicone oil spaces (RSS) on the visual axis was measured on the cross-sectional T1 weighted images (T1 WI) and T2WI, the length of the visual axis was measured on the fat-suppressed T2WI. The length of the visual axis was the distance from the corneal vertex to the macular foves, and it was also measured by A-mode ultrasound in sitting position with different ultrasonic velocity. The post-oil gap was also measured by A-mode ultrasound in supine position.Results Compared with the signal of the contralateral vitreous body, the silicone oil signal was higher on T1WI images, lower on T2WI images. After fat suppression, the silicone oil signal and chemical shift artifact were reduced. There were different levels of ASS and RSS in the vitreous cavity of all 32 cases, the RSS depth was (2. 47 ± 1.31) mm on average by MRI. However, RSS was detected in only 56.25%(18 cases) eyeballs by A-mode ultrasound. The visual axis length of silicone oil-filled eyes was (23.52 ±4.67) mm by MRI, and (20. 57±5.32) mm by A-mode ultrasound in sitting position. The differences between two measurements was statistically significant (t= 30. 17, P＜0. 05). Conclusions In addition to A-mode ultrasound, MRI might be another effective method to detect RSS and ASS, and to measure the axial length of silicone oil-filled eyes.     

青光眼诊断新技术需要临床应用评价

海德堡视网膜断层扫描仪、相干光断层扫描仪及偏振光激光扫描仪等检测技术广泛应用于青光眼临床诊断已有多年,但其实用价值和临床意义尚缺少明确而规范的评判标准.每种检测仪器均需要进行诊断试验评价,而评价方法应当正确、规范而严谨,重在早期诊断和不同指标诊断性能的具体分析.诊断技术只有在临床应用与应用评价相结合时,才能获得真正的发展,并进而解决实际问题.     

Sub-Tenon's administration of local anaesthetic: a review of the technique

Br J Anaesth 2003; 90: 787–93     

Cross-sectional study of the ophthalmological effects of carbon disulfide in Chinese viscose workers

This article presents cross-sectional investigation results of ophthalmological effects for the occupational exposure to carbon disulfide of workers at a large viscose fibre factory in the middle part of China. The total of 271 exposed subjects (191 males, 80 females) and 133 workers (93 males, 40 females) not exposed to any toxic agent in the working environment underwent ophthalmological examination. The self-administered questionnaire collected data on the medical history and ophthalmological complaints during the past three months. The ophthalmologic examination included routine examination for retinal capillary anomalies and and color vision with the FM 100-Hue test method. Nearly all subjects did not use respirators, smocks or aprons, gloves or other personal protective devices during work time. The average personal CS2 exposure level in the present study was 13.7-20.05 mg/m3. The FM 100-Hue test results showed that the total error scores of the exposed group, whether male or female, were higher than that of the control, the discrimination of the green and blue zones was also impaired significantly. A fundus examination showed no retinal capillary anomalies or other serious ophthalmological symptoms that may be related to effects of CS2. In conclusion, color vision was disturbed in workers exposed to CS2, at levels below the present threshold value. Reduced color discrimination may be attributed to long-term carbon disulfide exposure and suggests that health surveillance of workers exposed to carbon disulfide should include the FM 100-Hue Test as a sensitive and easy method.     

Plasma catecholamine response to cataract surgery: a comparison between general and local anaesthesia

We studied the plasma catecholamine, plasma glucose and cardiovascular responses to cataract surgery in 20 elderly patients allocated randomly to receive either general anaesthesia or local anaesthesia by retrobulbar block. Local anaesthesia prevented the increase in plasma noradrenaline, adrenaline and glucose concentrations found in those patients who received general anaesthesia and also improved cardiovascular stability. The results show the beneficial effects of local anaesthesia in preventing the hormonal, metabolic and cardiovascular changes found when cataract surgery is conducted under general anaesthesia.     

Research contributions in ophthalmology: Australia's productivity

Background: In 2000, the Australian and New Zealand Journal of Ophthalmology (ANZJO) changed title to Clinical and Experimental Ophthalmology. At this time, a review of Australia's contributions to the literature over the previous 21 years appears timely. Bibliometric indicators are used extensively to assess research performance as they offer views of a field that might not otherwise be apparent. The aim of this study was to explore publication output data to construct a picture of ophthalmology that may be of benefit to researchers and ophthalmologists. Methods: Science Citation Index and Social Sciences Citation Index databases were used to collate data on ophthal­mology research literature from 1980 to 2000. Subsequent analysis particularly focused on Australia's contribution to this literature, including publication frequency vis‐à‐vis the world, collaboration, and the journals in which Australian researchers frequently publish. These data were also compared with other countries of similar scientific stature or language. Results: Since 1980, Australia has ranked in the top 10 nations contributing to world ophthalmology research. Its contribution was close to world average in the 1980s, but increasing numbers of researchers and papers show Australia exceeding the world average during the 1990s. Most ophthalmology research collaboration by Australians is within Australia. Although fewer in number, collaborative papers with overseas researchers include 28 other countries. Data on the journals in which Australians publish show that Australian researchers continue to exhibit a preference for publication in their own regional journals. Conclusions: This paper, one of a series on the literature of the vision sciences, provides some initial benchmarks on Australia's standing and contribution to the field of ophthalmology research.