Red glasses and visual function in retinitis pigmentosa

As a consequence of animal studies reduction of the light regimes have been tried on patients with retinitis pigmentosa. The trials have been very limited and have not given reason for hope that such reduced light therapy may be beneficial. However, RP patients trying red glasses have reported acute subjective improvement of their visual function. It was the purpose of this study to try to document the reports more objectively. Five visual functions were tested with and without red glasses with the following results: 1. Visual acuity and contrast sensitivity. For one volunteer a small reproducible improvement was found. 2. Color vision. In most cases deterioration was found of already deficient color vision. 3. Visual fields. For volunteers with relatively preserved vision no difference or slight deterioration was found. For the other volunteers slight improvements were found. 4. Intraocular light scatter. No differences were found. 5. Dark adaptation. Improvements were found when the glasses were used as adaptation aid according to the method of Trendelenburg (rod function). For cone function no difference was found upon continuous wearing of red glasses.In conclusion: use of red glasses does not seem to be of great benefit as a rule. On the other hand, apart from the reduction in color discrimination no serious disadvantages seem to be inherent in their wear by RP patients.     

改良ABC设计的非球面IOL植入对白内障患者术后视觉质量的影响

目的:评估改良非球面平衡曲线(ABC)设计的非球面人工晶状体(IOL)植入术后的视觉质量,同时进行临床IOL选择的影响因素分析,指导患者的IOL选择方案。方法:前瞻性病例对照研究。选取拟行白内障超声乳化联合折叠式IOL植入术的单纯性白内障患者67例74眼,其中观察组植入改良设计IOL 23眼(HOYA Vivinex XY1组),对照组植入传统设计IOL 51眼(Tecnis ZCB00组27眼,IQ SN60WF组24眼),术后1wk, 1mo测量裸眼视力及最佳矫正视力、不同瞳孔直径下(3、4、5、6mm)全眼球差及彗差、不同瞳孔直径(3、4、5mm)下的调制传递函数(MTF)曲线、客观散射指数(OSI)、眼内散射光值Log(s)及对比敏感度。对所得的数据进行统计学分析。结果:三组术后1wk, 1mo裸眼视力及最佳矫正视力均较术前显著提高,组间均无差异(P>0.05)。术后全眼球差值比较,术后1wk, 5、6mm瞳孔直径下三组存在差异(P=0.045、0.037),术后1mo 6mm瞳孔直径下三组存在差异(P=0.042)。全眼彗差值比较,术后1wk, 1mo 5、6mm瞳孔直...     

脑白质病变MRI视觉分级方法的比较

目的:比较7种常用的脑白质病变(WMLs)MRI视觉分级方法,评价各分级之间的相关性和一致性,并计算两两间相互转化的参数.方法:随机选取50例MRI T2-FLAIR显示有不同程度WMLs患者,由两名医师分别用7种分级方法对其WMLs进行评分. 视觉分级间的相关性评价采用Spearman 等级相关分析,不同评估者之间的一致性分析采用Kappa检验,通过回归分析计算各分级间相互转化的参数.结果:不同视觉分级在WMLs评分上均有较强的相关性(相关系数rs: 0.579～0.917, P＜0.05). 除Schelten(modilified)分级和Ylikoski分级外,其它分级在不同观察者间的一致性好(κ＞0.585). 除Aharon-Peretz J分级和De Groot JC分级外,通过回归分析得出了其它5个分级间相互转化的参数,其确定系数R2的范围为0.5856～0.8892.结论:7种不同白质病变的MRI视觉分级间有较好的相关性,而不同评估者间Aharon-Peretz J分级的一致性最好.     

视觉电生理和视野检查对原发性开角型青光眼早期诊断的敏感性

目的:探讨多种视觉电生理联合全自动视野计检查对原发性开角型青光眼早期诊断中的敏感性,为临床早期诊断提供客观敏感的指标。方法:选择10例(20眼)原发性开角型青光眼患者和正常对照者10例(20眼)分别进行闪光视网膜电图(FERG)、图形视网膜电图(PERG)、图形视觉诱发电位(PVEP)检查;还对正常对照组、青光眼组中各5例(10眼)进行多焦视网膜电图(mERG)检查;青光眼组10例(20眼)和正常对照组8例(16眼)行蓝黄视野(B/Y)、标准视野(W/W)检查。结果:PERG的异常率较高,PERG的潜伏期延长较敏感,mERG二阶反应黄斑区振幅下降,随离心度的增大,振幅逐渐变小,潜伏期延长,PVEP的P100波振幅降低,潜伏期延长。B/Y视野异常与W/W视野异常比较有显著差异(P <0.01)。结论:B/Y视野检查联合多种视功能检查对原发性开角型青光眼早期诊断较敏感。早期诊断中的B/Y视野敏感性高;若眼压差大,眼底C/D未出现改变,则PERG可作为较敏感观测指标。     

Patterns of III nerve synkinesis

PURPOSE Various patterns of synkinesis have been observed following both congenital and acquired III nerve palsies. Aberrant regeneration is the most widely accepted mechanism which explains this synkinesis. Two models of aberrant regeneration have been proposed, namely central collateral axon sprouting, and misdirection of regenerating neurones at the site of nerve injury. We have studied the clinical patterns of III nerve recovery and synkinesis following III nerve palsies and relate the findings to the proposed models of synkinesis. MATERIALS AND METHODS Twelve patients with acquired and two with early onset III nerve synkinesis were reviewed. The type, rate and pattern of recovery of III nerve palsy was established from case notes. Observations and measurements of ocular motility, pupil movements, eyelid position and intraocular pressure changes were performed on each patient. Signs of contralateral synkinetic movements were also sought. RESULTS Upper lid retraction on attempted down gaze and in adduction was the most frequent synkinetic movement recorded. Observation of pupil size revealed evidence of pupillary-extraocular muscle synkinesis in all gaze positions except abduction. Similarly, intraocular pressure changes and signs of globe retraction showed widespread extraocular muscle co-contraction. Synkinetic levator innervation of extraocular muscles [i.e., LPS to MR, IR, SR] was also observed, a finding not previously reported in III nerve palsy but predicted by our model of misdirection of regenerating neurones at the site of nerve injury. There was no evidence of contralateral aberrant innervation. CONCLUSION Evidence of III nerve synkinesis in patients with III nerve palsy is widespread and the patterns of synkinesis observed were broadly similar for all patients irrespective of the aetiology. Random aberrant III nerve regeneration at the site of nerve injury best explains the patterns of synkinesis observed. Central collateral axon sprouting does not seem to play a major part in the synkinetic movements observed in acquired III nerve lesions.     

One-stage vs. two-stage adjustable sutures for the correction of esotropia

BACKGROUND The aim of this study was to evaluate the stability and the level of postoperative consciousness, nausea and vomiting, ocular pain, starting oral intake and activity, and cost-effectiveness in patients undergoing medial rectus recession surgery using an adjustable suture technique that was performed by two different methods. METHOD In this prospective study, we evaluated 78 patients undergoing medial rectus recession surgery. Thirty-eight patients were operated by a one-stage technique in which the whole operation was done under topical anesthesia and adjustment was done on the operating table, while 40 patients were operated by a two-stage technique in which the operation was done under general anesthesia and adjustment was done the following day at the patient’s bedside. The results were recorded and compared according to the parameters given above. A scoring system was used to assess all these parameters except for stability. The stability of the procedures was evaluated according to the degrees of squint immediately after the adjustment and at least three months thereafter. RESULTS There was no significant difference between the procedures with regard to stability and ocular pain. During the early postoperative period, the level of consciousness was better and nausea and vomiting occurred less frequently in the patients operated by the one-stage procedure. Postoperative activity and oral intake returned to normal status more quickly in the one-stage group and the one-stage procedure was cost-effective. CONCLUSION We conclude that although both procedures provide satisfactory and stable results, the one-stage procedure has significant advantages over the two-stage procedure for medial rectus recession surgery in suitable cases.     

Healthy aging impairs face discrimination ability

Face images enable individual identities to be discriminated from one another. We aimed to quantify age-related changes in different aspects of face identity discrimination. Face discrimination sensitivity was measured with a memory-free “odd-one-out” task. Five age groups (N = 15) of healthy adults with normal vision were tested: 20, 50-59, 60-69, 70-79, and 80-89. Sensitivity was measured for full-face images (all features visible), external features (head-shape, hairline), internal features (nose, mouth, eyes, and eyebrows) and closed-contour shapes (control object). Sensitivity to full-faces continuously declined by approximately 13% per decade, after 50 years of age. When age-related differences in visual acuity were controlled, the effect of age on face discrimination sensitivity remained. Sensitivity to face features also deteriorated with age. Although the effect for external features was similar to full-faces, the rate of decline was considerably steeper (approximately 3.7 times) for internal, relative to external, features. In contrast, there was no effect of age on sensitivity to shapes. All age groups demonstrated the same overall pattern of sensitivity to different types of face information. Healthy aging was associated with a continuous decline in sensitivity to both full-faces and face features, although encoding of internal features was disproportionately impaired. This age-related deficit was independent of differences in low-level vision. That sensitivity to shapes was unaffected by age suggests these results cannot be explained by general cognitive decline or lower-level visual deficits. Instead, healthy aging is associated with a specific decline in the mechanisms that underlie face discrimination.     

Long-term Results of Cryotherapy for Active Stages of Retinopathy of Prematurity

Between 1976 and 1980, retinopathy of prematurity (ROP) stage III (moderate) (fibrovascular proliferation) developed in 29 eyes (confluent fibrovascular proliferation of 3 clock hours in extension) of 17 preterm babies. The eyes were treated by cryopexy to the avascular retina. Analysis of the visual function and anatomic results in these eyes, five to eight years postoperatively, revealed very good visual function and only a few anatomic abnormalities. Comparison of these eyes with those of two groups of age- and birth-weight-matched preterms (one with less severe ROP, not treated by cryopexy, and the other with no ROP) showed that the degree of myopia was significantly higher in the cryotreated group. Although not statistically significant, there was a higher incidence and a greater degree of astigmatism in this study group.     

Predictors of women's perceptions of the childbirth experience

OBJECTIVE: To determine the factors that predict women's perceptions of the childbirth experience and to examine whether these vary with the type of birth a woman experiences. DESIGN: Prospective cohort study. SETTING: The postpartum units of two eastern Canadian hospitals. PARTICIPANTS: Six hundred fifty two women and their newborns. DATA COLLECTION: Data were collected in hospital at 12 to 48 hours postpartum using self-report questionnaires and chart review. MAIN OUTCOME MEASURE: Perception of the childbirth experience was measured for women having a vaginal and emergency cesarean birth using the Questionnaire Measuring Attitudes About Labor and Delivery and planned cesarean birth using the Modified Questionnaire Measuring Attitudes About Labor and Delivery. RESULTS: Of the 20 predictors of women's childbirth perceptions, the strongest were type of birth; degree of awareness, relaxation, and control; helpfulness of partner support; and being together with the infant following birth. CONCLUSIONS: Of the predictors of a quality birth experience, most were amenable to nursing interventions: enhancement of patient awareness, relaxation, and control; promotion of partner support; and provision of immediate opportunities for women to be with their babies.