FUNDUS REFLECTOMETRY IN RETINITIS PIGMENTOSA

X-连锁视网膜色素变性(XLRP)是一种严重、进展迅速和 无法治愈的视网膜变性。分子遗传学研究最近 提供了XLRP内部可能存在异质性的证据。这些 不同的可能的基因类型与表型没有明显的关系。 由目前唯一的XLRP临床分类方案定义 使用。这项建议中的研究旨在提供一个新的分类 基于检查异常视网膜机制的XLRP方案 非侵入性视网膜功能检测中的半合子和杂合子 已被证明在定义不同表型方面有价值的技术 常染色体显性遗传的Rp。 已经进行了初步的电生理和心理物理研究 提示视网膜功能障碍有明显不同的模式 年轻的XLRP半合子。在全视野视网膜电描记术中，有两种 视杆-视锥细胞介导的功能障碍的不同关系；以及与视杆 和锥体视野，这两种模式都得到了确认，并且它们的区域 定义了视网膜变异。XLRP半合子的两种功能表型 表现出独特的特征，当与功能障碍的模式相比 特征性良好的视网膜退行性变，如I型和II型RP和 视锥-杆状营养不良。用视杆和视锥视野检查杂合子显示 轻度功能障碍斑块与视杆-视锥异常的关系 就像半合子里的那些。中类似的功能模式的示例 杂合子和半合子来自同一个家族。 拟议的工作是扩大这些初步观察结果。半合子 将用视杆和视锥视网膜电图仪、视杆和视锥进行测试 视野检查和暗适应检查以确定功能障碍和 确定它们在谱系中是否一致。来自中国的杂合子 同样的家系将用杆状和锥状视野检查和适应性检查进行测试 以及功能障碍的模式相互比较，以及与 相关半合子以确定疾病是否在斑块中表达 杂合子状态的视网膜病变是 半合子。

X-linked retinitis pigmentosa (XLRP) is a severe, rapidly progressive and incurable retinal degeneration. Molecular genetics research has recently prOvided evidence that there may be heterogeneity within XLRP. These different putative genotypes have shown no clear relation to the phenotypes defined by the only clinical classification scheme of XLRP currently in use. The studies in this proposal aim to provide a new classification scheme of XLRP based on abnormal retinal Mechanisms by examining hemizygotes and heterozygotes with non-invasive retinal function test techniques that have proven valuable in defining the different phenotypes Of autosomal dominant RP. Preliminary electrophysiological and psychophysical studies already indicate there are distinctly different patterns of retinal dysfunction in young XLRP hemizygotes. With full field electroretinography, there are two different relationships of rod- to cone-mediated dysfunction; and with rod and cone perimetry, these two patterns are confirmed and their regional retinal variations defined. Both functional phenotypes in XLRP hemizygotes show unique features when compared to the patterns of dysfunction in well-characterized retinal degenerations such as Types I and II RP and cone-rod dystrophy. Heterozygotes tested with rod and cone perimetry show patches of mild dysfunction with relationships of rod to cone abnormality like those in the hemizygotes. Examples of similar functional patterns in a heterozygote and hemizygote from the same family have been found. The proposed work is to extend these preliminary observations. Hemizygotes will be tested with rod and cone electroretinography, rod and cone perimetry and dark adaptometry to define the patterns of dysfunction and determine if they are consistent within pedigrees. Heterozygotes from the same pedigrees will be tested with rod and cone perimetry and adaptometry and the patterns of dysfunction compared with one another and with those in related hemizygotes to determine if the disease expression in the patchy retinopathy of the heterozygous state is representative of that in the hemizygotes.