闪光视觉诱发电位监测甘露醇降颅压效果的临床研究

目的利用闪光视觉诱发电位监测颅内高压患者颅压水平,研究降颅压效果与甘露醇用量以及其他影响因素的关系。方法选择60例颅内高压患者,应用NIP-200型无创颅内压监测仪监测患者每日颅压,计算最高颅压与最低颅压间的差值(降颅压效果),采用多元逐步回归方法分析降颅压效果与性别,年龄,最高颅压时的心率、血压以及降至最低颅压时甘露醇总用量的关系。结果60例患者最低颅压平均值为(213·4±66·8)mmH2O(83·5~364·5mmH2O),患者的颅压水平从入院至最低值时甘露醇总用量的平均值为(1870·8±861·9)ml(375~4000ml)。降颅压效果与最高颅压时的血压(舒张压和收缩压)和心率无相关性(P>0·05),与性别、年龄显著相关(P<0·05),与甘露醇用量显著相关(P<0·01)。结论甘露醇有明显的降颅压作用,但是用到一定的剂量后,便不再有降颅压作用。女性患者比男性患者降颅压的效果好。患者年龄越小,降颅压效果越好。     

Distribution of neuropeptide Y-like immunoreactivity in the brain of the lizard Gallotia galloti.

The distribution of neuropeptide Y (NPY)-like immunoreactivity was studied in the brain of the lizard Gallotia galloti, in order to gain insight into the comparative topography of this peptide. Antisera against both NPY and its C-terminal flanking peptide (C-PON) were used, demonstrating a general coexistence of both peptides, as described in other vertebrates. Most NPY-like immunoreactive (NPY-LI) cell bodies were observed in the telencephalon, specifically in various olfactory structures, all cortices, septum, basal ganglia (except for the globus pallidus), the nucleus of the diagonal band of Broca, the amygdaloid complex, and the bed nucleus of the anterior commissure. NPY-LI cells were also seen in the preoptic and hypothalamic regions and the dorsal thalamus (mainly in the perirotundal belt), as well as in the mesencephalic tegmentum (in the ventral tegmental area, the substantia nigra, and the retrorubral area). NPY-LI fibers and terminals were widely distributed in the brain. All visual and auditory neuropiles were densely innervated. Specially dense plexuses were seen in the nucleus accumbens, the ventral pallidum, the suprachiasmatic and ventromedial hypothalamic nuclei, the nucleus medialis thalami, the left habenula, and the central nucleus of the torus semicircularis. Our analysis shows that the distribution of NPY-like immunoreactivity in the forebrain of Gallotia largely resembles that of other vertebrates, whereas differences are mainly observed in the brainstem. The widespread distribution of NPY in the lizard brain suggests several modulatory functional roles, either in local-circuit systems of the forebrain, or in various limbic, neuroendocrine, and sensory pathways.     

Near visual acuity: a simple measure of practical significance in insulin-treated diabetic patients.

The value of measuring near visual acuity as a predictor of loss of independence in administering insulin and monitoring blood or urine glucose has been assessed in 110 insulin-treated diabetic patients. Near visual acuity was simple to measure in the clinic setting, and correlated well with 6 m acuity. Fourteen patients depended on an assistant either to draw up the correct dose of insulin (n = 12), inject the insulin (n = 7) or to monitor blood or urine glucose (n = 12). Of these 14 patients only one, who was demented, had near visual acuity better than N.12. Two other patients had near visual acuity N.12 or worse and yet were independent of help. One had severe visual impairment and used a pen-injector and a meter with speech synthesizer, and the other had near visual acuity of N.12. Impairment of near visual acuity to N.12 or worse is associated with loss of independence in insulin-treated diabetes. Measurement of near visual acuity could be useful in predicting independence of insulin-treated patients.     

眼眶骨折眼球内陷功能性复位手术的临床观察

目的：研究眼眶骨折眼球内陷手术复位的方法和手术最佳时期，探讨手术前后视功能变化。方法：应用螺旋CT影像和视觉电生理检查技术对100例施行眼眶重建和眼球复位手术的患者进行观察研究。结果：在早期手术的40例患者中，28例眼球内陷完全复位，12例改善；60例晚期手术中，32例完全复位，28例得到部分改善；手术前后视网膜电流图（F—ERG）和视觉诱发电位（P-VEP）无显著性差异。结论：采用人工材料行眼眶重建和眶内充填技术手术治疗眼球内陷可获得满意的疗效，早期手术效果优于晚期手术，手术创伤对视功能无明显影响，眼眶重建和眼球复位手术是安全可行的。     

准分子激光原位角膜磨镶术患者主客观因素与疗效的相关性分析

目的：通过对准分子激光原位角膜磨镶术(LASIK)患者主客观因素与疗效的相关性分析，了解临床影响术后视力的主观、客观因素。方法：对2002年间在我院行ASIK的164例患者325只眼(其中3例为单眼)进行连续性临床观察研究，分别进行术前、术后问卷式主客观因素调查，并对患者手术疗效进行相关性统计学分析。结果：患者术前对手术效果的期望值、手术中疼痛程度与手术后视力有显著相关性。结论：解除患者术前忧虑及避免术中疼痛对提高术后疗效有重要意义。     

Users' subjective evaluation of electronic vision enhancement systems

The aims of this study were (1) to elicit the users' responses to four electronic head-mounted devices (Jordy, Flipperport, Maxport and NuVision) and (2) to correlate users' opinion with performance. Ten patients with early onset macular disease (EOMD) and 10 with age-related macular disease (AMD) used these electronic vision enhancement systems (EVESs) for a variety of visual tasks. A questionnaire designed in-house and a modified VF-14 were used to evaluate the responses. Following initial experience of the devices in the laboratory, every patient took home two of the four devices for 1 week each. Responses were re-evaluated after this period of home loan. No single EVES stood out as the strong preference for all aspects evaluated. In the laboratory-based appraisal, Flipperport typically received the best overall ratings and highest score for image quality and ability to magnify, but after home loan there was no significant difference between devices. Comfort of device, although important, was not predictive of rating once magnification had been taken into account. For actual performance, a threshold effect was seen whereby ratings increased as reading speed improved up to 60 words per minute. Newly diagnosed patients responded most positively to EVESs, but otherwise users' opinion could not be predicted by age, gender, diagnosis or previous CCTV experience. User feedback is essential in our quest to understand the benefits and shortcoming of EVESs. Such information should help guide both prescribing and future development of low vision devices.     

Impaired cardiovascular autonomic function in Parkinson's disease with visual hallucinations.

We assessed the relations of visual hallucinations (VH) to cardiovascular autonomic dysfunction in patients with Parkinson's disease (PD). The subjects were 37 patients without VH (VH(-)) and 31 with VH (VH(+)). Autonomic function was evaluated on the basis of cardiac 123-radioiodinated metaiodobenzylguanidine (123I-MIBG) uptake and hemodynamic testing with Valsalva maneuver. Systolic blood pressure (SBP) and plasma norepinephrine concentrations (NE) were measured by tilt-table testing. 123I-MIBG uptake was lower in VH(+) than VH(-). Hemodynamic studies showed that VH(-) had only cardiac sympathetic and parasympathetic dysfunction, while VH(+) additionally had reduced vasomotor sympathetic functions. The fall in SBP during tilt-table testing was greater in VH(+) than VH(-). NE and its difference in the supine and upright positions were decreased in VH(+). We conclude that cardiac and vasomotor sympathetic dysfunction is more severe in VH(+) than in VH(-). Severe dysfunction in PD with VH is probably attributed to Lewy-body lesions or neuronal loss in sympathetic ganglia, the central autonomic system, or both.     

Age, lens transmittance, and the possible effects of light on melatonin suppression

Recently it has been suggested that a previously undetected, rhodopsin-based, visual pigment, located in some retinal ganglion cells and having a peak sensitivity around 460 nm, may be responsible for light-induced melatonin suppression and, perhaps, maintenance of the circadian rhythm. Using data from the literature, it is shown that, as absorption in the crystalline lens for shorter visible wavelengths increases substantially with age, while the pupil diameter tends to decrease, the effective retinal exposure received under the same ambient lighting conditions by the pigment is almost 10 times lower in an old, as compared with a young, eye. Interestingly, replacement of the old crystalline lens by an intraocular implant restores the exposure to youthful levels. The possible effects of these changes with age on circadian rhythms are discussed.