中医药治疗原发性视网膜色素变性的临床观察

目的观察中医药治疗原发性视网膜色素变性的临床疗效。方法采用补肾养血明目汤加减,静脉滴注舒血宁和生脉注射液,口服银杏叶片、生脉颗粒及针灸等综合治疗视网膜色素变性64例（128只眼）。结果好转63只眼,无效65只眼,有效率为49%。结论中医药治疗原发性视网膜色素变性是有效的方法。     

视网膜色素变性家系应用助视器的效果随访分析

目的探讨助视器在视网膜色素变性(RP)患者中的应用价值。方法分析一例RP家系的患病家谱、患者的生活视力以及验配助视器后的效果。结果该家系4代人中患病12例,其中3人日常生活视力均≤0.12,应用2.8×2.8倍眼镜式远用助视器后,其康复视力分别达到了0.4、0.4、0.6,摆脱了低视力困扰。结论助视器可提高RP患者的生活视力和生活质量,其临床价值应得到重视。     

Differential Expression of Photoreceptor-Specific Proteins During Disease and Degeneration in the Progressive Rod-Cone Degeneration (prcd) Retina

Progressive rod-cone degeneration (prcd) is a late-onset hereditary retinal degeneration characterized by normal development of photoreceptors prior to degeneration and death of visual cells. We reported previously that expression of opsin mRNA and protein decreases prior to visual cell degeneration. To examine the specificity of this reduction, we have used immunocytochemistry to correlate photoreceptor-specific protein expression with visual cell disease progression. Eyes from light-adapted age-matched control andprcd-affected dogs were fixed in paraformaldehyde, embedded in diethylene glycol distearate (DGD) wax, and reacted with antibodies specific to interphotoreceptor retinoid-binding protein (IRBP), S-antigen, opsin, phosducin, γ-phosphodiesterase (γ-PDE), and β₁-transducin. While IRBP expression did not change with disease progression, immunoreactivity to other proteins varied. For S-antigen and opsin, immunoreactivity decreased dramatically with the transition from photoreceptor disease to degeneration; γ-PDE immunolabeling in rods also decreased, but the reduction was less abrupt. However, for two other proteins (phosducin and β₁-transducin), immunoreactivity increased initially and was redistributed (particularly to the rod outer segment) in early disease (stage 1). Our results show that there is a differential expression of photoreceptor-specific proteins with disease and degeneration that is not uniform for all the gene products examined; expression can be decreased, altered in distribution or remain unchanged. It is clear that the decrease of opsin expression described previously is not an isolated phenomenon in the progression ofprcd, but is part of a more generalized degenerative process which eventually culminates in cell death.     

Retinitis pigmentosa, AD type I: exclusion of linkage to D3S47 (C17) in a large South African family of British origin

Linkage analysis has been performed on a large South African family of British origin in which 39 persons in 6 generations had early onset Type I autosomal dominant retinitis pigmentosa (ADRP). Tight linkage was excluded between the disease and the D3S47 locus on chromosome 3. This finding is further evidence for genetic heterogeneity in ADRP.     

Attitudes towards prenatal diagnosis and selective abortion among patients with retinitis pigmentosa or choroideremia as well as among their relatives

Genetic counselling endeavours to be nondirective. However, the availability of prenatal diagnosis may direct clients towards accepting and using these methods. It is time to investigate the attitudes of clients in order to monitor the psychological and social effects of new genetic techniques. As prenatal diagnosis was possible for choroideremia (C), but not for retinitis pigmentosa (RP) in 1988–89, we used a questionnaire to compare the attitudes of C and RP patients, their relatives and C carriers to prenatal diagnosis. The response rate was low (35%) and no significant differences between RP and C groups came to light. However, C carriers accepted prenatal diagnosis and also selective abortion more easily, but, on the other hand, they showed more uncertainty than did the other groups. This indicates that the availability of prenatal diagnosis may confuse those concerned. In general, about 60% of all the respondents had a positive attitude to the prenatal diagnosis of RP or choroideremia, though only about 30% would use it for abortion. Over 80% of all the respondents wanted to know the opinion of the genetic counsellor.     

A variant form of metachromatic leucodystrophy in a patient suffering from another congenital degenerative neurological disease

A woman aged 21 with a variant form of metachromatic leucodystrophy (MLD) combined with another form of leucodystrophy is described. The clinical symptoms were retinitis pigmentosa and progressive neurological deficits such as mental retardation, dystonia, pyramidal tract involvement and peripheral neuropathy. The biochemical findings were marked deficiency of arylsulfatase-A and cerebroside-sulfatase in cultured fibroblasts and excretion of sulfatides in the urine. Sulfatide-loading of cultured fibroblasts showed almost normal uptake and degradation of sulfatides. The patient's sister suffers from a clinically similar neurological disease, but normal activity of arylsulfatase-A was found in her leucocytes. A severe oral-facial dystonia in the patient was successfully controlled by l-dopa.     

Retinitis Pigmentosa: A Symposium on Terminology and Methods of Examination

This report represents a summary of opinions expressed at a meeting of specialists interested in retinitis pigmentosa (RP) and allied diseases, at which an attempt was made to define some minimum guidelines for ocular evaluation of these disorders. The term RP would be reserved for a group of hereditary disorders that diffusely involve photoreceptor and pigment epithelial function, and should not be used when a secondary cause is suspected. RP may be classified by genetic type (single cases without known affected relatives should be termed isolated or simplex), by the topography of retinal involvement, and by the severity of disease (to identify subtypes with mild or localized disease). Patients should have at least one comprehensive examination that conforms to basic standards, preferable early in the course of the disease. The visual field examination should use both a small and a large test light. Electroretinographic testing should (1) use a full-field stimulus, and (2) routinely document three independent responses (cone, rod, and mixed conerod). Patients should be identifiable for future study or therapeutic trials. They should be counseled about the disease and followed regularly. No specific therapy exists at present for most of these diseases, but optical and night vision aids are available. Sunglasses for outdoor use are recommended until more is known about whether long-term exposure to bright sunlight alters the course of these diseases.     

Reduced ocular glucose transport and increased non-electrolyte permeability in rats with retinal degeneration (RCS)

The transport kinetics across the plasma-ocular barriers of labeled molecules including urea, D-glucose, 3-0-methyl-D-glucose, L-glucose, and sucrose were studied in adult RCS rats and compared to control albino Sprague-Dawleys (SD). Results indicate that substances that passively cross the plasma-aqueous and plasma-vitreous barriers (urea, sucrose, L-glucose) do so more readily in the RCS rat especially via the trans-retinal route. By contrast, D-glucose, which penetrates the ocular barriers of the control rat by a carrier-mediated mechanism was found to cross the ocular barriers of the RCS rat at a reduced rate. Thus, the ocular barriers of the RCS rat with well developed retinal degeneration demonstrate an increase in passive permeability and a reduction in ability to perform their membrane transport function (D-glucose). The permeability defect was more pronounced in the blood-vitreous barrier than in the blood-aqueous barrier.     

A Dominantly Inherited Chorioretinal Degeneration Resembling Sectored Retinitis Pigmentosa

A light and electron microscopic study of an eye from a 79-year-old woman diagnosed as having sector retinitis pigmentosa is presented. Prominent bone spicule pigmentation was present bilaterally in the nasal quadrant. Retinal structure in the central fundus around the fovea and extending 2–3 mm peripherally was near normal with all photoreceptors and other retinal neurons present. Extensive degeneration of the retina occurred as one proceeded toward the peripheral regions from 3–5 mm from the fovea in all quadrants. Changes were evident within the entire choroid and were most severe in regions where retinal degeneration was most pronounced. It is likely that the extensive degenerative changes present in the retina were secondary effects that follow alterations in the choroidal blood supply in individuals affected with this disorder.     

A leucine to arginine amino acid substitution at codon 46 of rhodopsin is responsible for a severe form of autosomal dominant retinitis pigmentosa

To evaluate the extent to which rhodopsin mutations are involved in autosomal dominant forms of retinitis pigmentosa (adRP) we collected DNAs from patients with adRP and screened the rhodopsin coding sequence with single-strand conformational polymorphism (SSCP) analysis and DNA sequencing. This screening revealed a thymidine to guanine transversion at nucleotide 431 (nucleotide sequence numbers as per Genebank) in affected members of one family (RFS04). The nucleotide substitution leads to a missense mutation at the 46th amino acid of rhodopsin. The mutation occurs at an amino acid conserved in mammals and changes the hydrophobic nature of the protein at a transmembrane-spanning region. The mutation causes the substitution of a non-polar hydrophobic amino acid, leucine, for the basic amino acid arginine (Leu46Arg). This nucleotide substitution is unique to the family studied and occurs in the affected individuals in the family. Full-field electroretinograms (ERGs) in four affected members of the family showed nondetectable rod responses at an early age, with markedly reduced cone responses, and a faster than average rate of progression of the phenotype as measured by yearly ERGs. © 1993 Wiley-Liss, Inc.