高度近视的病因学研究进展

高度近视发生的内因、外因，包括遗传倾向，相关基因定位，巩膜胶原白体免疫学说，视网膜生物活性物质失调学说，环境因素等，本研究就这些因素对高度近视发病的影响做一综述。现统一的认识有：①高度近视具有明显的遗传倾向。②迄今为止，已找到4个高度近视相关基因，它们的遗传方式均为常染色体显性遗传。③高度近视的巩膜组织病理改变和胶原代谢障碍引发了人们对高度近视免疫相关基因的深入研究。已发现HLAⅡ类基因与部分高度近视具有相关性。④视网膜中存在的生物活性物质直接或间接参与了形觉剥夺性近视的形成。⑤环境因素并非高度近视发病的决定因素，它仅起一定程度的促进作用。将今后的工作重点放在高度近视基因定位的研究，基因表达的调控及巩膜胶原代谢、网膜生物活性物质之间的关系研究上，无疑会进一步揭示高度近视的病因，为防治高度近视开辟新途径。     

572例近视眼患者中央角膜厚度测量报告

本文作者在572例(1144只眼)近视眼患者拟行角膜放射状切开(RK)手术前,对角膜不同部位厚度进行了测量,对其值作统计学处理,均值及标准差为0.527±0.037mm,标准误为0.002,说明我国95％的近视眼患者中央角膜厚度范围为0.455—0.600mm。提示我国成人各年龄组左、右眼角膜厚度与左、右眼屈光度、性别、眼别无关。强调RK手术前对角膜厚度测量的重要性,但手术预后优劣为多因素所致。     

放射状角膜切开的实验病理与临床应用

以１４只兔及２只猴为动物模型，对放射状角膜切开术（ＲＫ）进行了２￣３个月观察，发现：ＲＫ切口内的上皮塞子持续２个月以上才逐渐消退。术后一个月内上皮下基底膜形成，后逐渐变薄，切口内的成纤维细胞分裂增殖较慢，开始走行与切口平行，１５天后可见横过切口，２月后实质表层成纤维细胞排列变得整齐，但深层仍较紊乱，胞核多深染。术中切穿角膜的实验兔，术后２个月病理切片可见：切口附近内皮细胞丢失，内弹力膜断裂，切口内     

丝裂霉素C及可调整缝线在小梁切除术中的应用

目的 观察丝裂霉素C联合可调整缝线在青光眼小梁切除术中应用的效果。方法 我院近3年来小梁切除术98例,术中采用巩膜瓣下放置含丝裂霉素C棉片2～5分钟,然后迅速以平衡盐溶液冲洗,切除2mm×3mm包括小梁在内的深层角巩膜缘组织,并做虹膜根部切除,用10-0尼龙线间断缝合巩膜瓣2～4针后,再于巩膜瓣一侧或两侧作1条或2条型巩膜瓣缝合。形成前房。术后2周、3月、1年及1.5年检查视力、眼压、前房、滤过泡等情况。结果 术后眼压控制良好,Ⅰ、Ⅱ度浅前房发生率低,滤过泡形成良好,43％视力保持不变或改善,炎症反应轻,并发症少。结论 丝裂霉素C可提高小梁切除术后眼压控制率,联合可调整缝线,可有效控制术后滤过水平,减少术后并发症,提高成功率。     

RGPCL矫正60例中低度近视的初步观察

目的评价高透氧性硬性角膜接触镜(RGPCL)矫正控制中低度近视屈光不正的效果。方法采用RGPCL矫正120眼中低度近视性屈光不正,统计矫正后当天、1年时近视屈光度、散光度的变化。结果观察组的近视度和散光度随戴镜时间延长相对稳定。结论RGPCL对中低近视的度数控制有效。     

Case Report: 49, XXXXY syndrome and high myopia

49, XXXXY karyotype syndrome has been thought of as a variant of Klinefelter's syndrome. It has an incidence of between 1/85 000 to 1/100 000 live births. Typical clinical features include coarse faces, skeletal abnormalities, hypogenitalism and severe learning difficulties. Common ocular features include hypertelorism, epicanthic folds and up-slanting palpebral apertures. Here we report a case of high myopia and its successful correction leading to a positive personality change in one such patient. We advocate full ophthalmic examination, under anaesthesia if necessary, and a trial of refractive correction, even in children thought unlikely to tolerate such.     

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

病理性近视眼的研究进展

通过复习近年来相关文献,对近视眼发生发展机制与形觉剥夺之间的关系进行综合评述。认为近视眼的发生及眼轴延长与形觉剥夺有一定关系,深入研究其相关机制,对近视眼的早期防治具有重要意义。     

Variation of multifocal electroretinogram with axial length

INTRODUCTION: The first-order kernel response of multifocal electroretinogram (mfERG) decreases in myopia. A recent study indicates that the flash ERG is also reduced with increased axial length. The aim of this study was to investigate the variations in the first-order response (K1) and the first slice of second-order response (K2.1) across the retina for different axial lengths. METHODS: Thirty healthy subjects with axial length from 23.72 to 28.13 mm (spherical equivalent refractive errors from plano to -10.50 D) were recruited for mfERG measurement using VERIS 4.0. All subjects were fully corrected after cycloplegic refraction and pupils were dilated prior to mfERG recording. There is one trough, n1, and one peak, p1, in the K1 response and three troughs, n1, n2, n3, and three peaks, p1, p2, p3, in the K2.1 response. The amplitudes and implicit times of K1 and K2.1 responses were analysed to determine the characteristic of the responses across retina and the correlation to axial length. RESULTS: The amplitudes of p1 (in the first-order kernel-K1) decreased in the central region and the paracentral region (ring 3) as the axial length increased. The central retinal region showed high rates of reduction in both n1 and p1 (in K1). The amplitudes of n1p1 and n2p2 (in the first slice of the second-order kernel-K2.1) were reduced in the paracentral region (from ring 2 to ring 5) as axial length increased. The average n1 and p1 in K1, and n1p1 and n2p2 in K2.1 mfERG responses are decreased in amplitude by 6-10% per millimetre elongation of axial length. CONCLUSION: Eyes with longer axial lengths, usually with high myopia, have a weaker mfERG response and this attenuation is across the measured retina (from central to paracentral regions) but different kernel responses show a different pattern of attenuation at different retinal eccentricities. The weaker mfERG responses may be related to the morphological changes associated with increased axial length.     

The relationship between the Stiles–Crawford effect of the first kind (SCE-I) and myopia

The Stiles-Crawford effect of the first kind (SCE-I) was measured on both emmetropic and myopic subjects at six different retinal locations. The results revealed a number of significant discrepancies in receptor alignment between the groups of different refractive errors. In myopic subjects, the receptors in the nasal retina (i.e. between the fovea and the optic nerve head) were found to be aligned nasally towards the optic nerve head, whereas the receptors in the temporal retina were aligned towards the centre of the exit pupil. In emmetropic subjects, the receptors across the retina were finely tuned towards the centre of the exit pupil. The magnitude of the receptor displacement in myopic subjects was found to be directly associated with the length of the eyeball.