Retinitis pigmentosa is a hereditary disease which is characterized by damage in retinal photoreceptor cells and retinal pigment epithelium. Its main clinical features include low vision with night blindness, progressive visual field defects, and abnormal electroretinograms. The development of gene sequencing, the diagnosis and treatment methods of retinitis pigmentosa update year by year, including gene therapy, stem cell therapy, optogenetic therapy, etc. However, there is still a big gap in these treatments from laboratory technology into effective clinical treatment drugs. Some problems which include immune response, potential mutagenesis and tumorigenesis of the inserted region, genetic toxicity, quality and stability of gene technology and stem cell technology, mass production and promotion of clinical grade drugs, and optimization of the effectiveness of drugs and surgery, etc, remain to be solved by researchers.
Objective To investigate the cilinical value of indocyanine green angiography(ICGA) in patients with Vogt-Koyanagi-Harada syndrome(VKH). Methods Fundus fluorescein angiography(FFA) and indocyanine green angiography(ICGA) were used for comparative analyses in 26 cases(52 eyes)of VKH. Results In the acute stage of VKH,FFA revealed the multifocal leakage in the pigment epithelium and the multifocal serous retinal detachment,and the typical FFA manifestations disappeard following treatment．In the acute stage of the disease the ICGA showed:(1)numerous patchy areas of hypofluorescence and decreased flurescence in large and middle choroidal vessels(66.7%);(2)dilatation of the choroidal vessels(70.8%)and(3)in latephase of ICGA,the patchy areas of hyperfluorescence(79.2%).During the recovery stage of the disease,the abnormal undings in ICGA were resolved slower than those found in FFA. Conclusions ICGA may assist in providing valuable informations on choroidal circulation of VKH and be useful in evaluating the curative effects． (Chin J Ocul Fundus Dis,20000,16:9-11)
Cilia are hair-like protuberance on cells of the human body that play a vital role in organs generation and maintenance. Abnormalities of ciliary structure and function affect almost every system of the body, such as the brain, eyes, liver, kidney, bone, reproductive system and so on. Retinal photoreceptor cells are one of sensory neurons which convert light stimuli into neurological responses. This process, called phototransduction, takes place in the outer segments (OS) of rod and cone photoreceptors. OS are specialized sensory cilia, and disruptions in cilia genes, which are causative in a growing number of non-syndromic retinal dystrophies, such as retinitis pigmentosa, Leber’s congenital amaurosis. These syndromes are genetically heterogeneous, involving mutations in a large number of genes. They show considerable clinical and genetic overlap. At present, there are few researches on retinal ciliopathies and clinical treatment strategy. This review shows a comprehensive overview of ciliary dysfunction and visual development related diseases, which contributes to understand the characteristics of these diseases and take early intervention in clinic.
Objective To observe the mutifocal electroretinogram (mfERG) characteristics of rod and cone cells in patients with retinitis pigmentosa (RP) and to evaluate the function of photosensory cell.Methods The mfERG recording technique for rod cell in eight normal subjects (eight eyes) were established and the influence of different brightness lightstimulus in P1 wave amplitude were analyzed. The cone and rod cells mfERG of 38 eyes in 19 patients were recorded and then calculated positive ratio from local signalnoise ratio. The average visual acuity and P1 wave amplitude density of cone mfERG in different types were compared and statistically analyzed. Meanwhile, the changes in P1 wave amplitude of cone and rod mfERG in four quadrants also compared and analyzed. Results Rod cell mfERG in normal subjects can be recorded stably by using blue flashes with low light intensity as 0.04 cd/m2. In patients with RP, the cone and rod cells mfERG can be detectd 65.79% and 10.51% respectively. P1 wave amplitude density in type I of cone cell mfERG was significantly higher than that in type II (t=5.21,P=0.000). There were no differences in average visual acuity (t=1.15, P=0.612). P1 wave amplitude density in type I was negatively related to logMAR visual acuity （r=-0.48，P=0.04）.The comparison of rod and cone cells mfERG in local wave characteristics showed that P1 wave amplitude densities had spatial relationship in each area. Conclusions The results suggested highly variable central responses in cone cell in RP patients, higher positive recorded ratio in cone cell than rod cell and spatial correspondence between the function of reserved cone and rod cells.
Objective To investigate the feasibility of gene transfection into retinal pigment epithelial (RPE) cells and photoreceptors (PRs) in vivo electroporation. Methods A total of 147 Sprague-Dawley (SD) rats were divided into 5, 10, 15, 20, 25, 30 and 35 V group according to different voltage. The right eyes of rats underwent the injection of eukaryotic expressive plasmid of enhanced green fluorescent protein (EGFP) pEGFP-N1 into subretinal space as experimental eyes; the left eyes were injected with TE buffer as control eyes. Each group was divided into RPE and RP subgroups according to different transfection direction. There were same parameters of 99 ms pulse width, 0.5 s pulse interval and 5 consecutive pulses except different voltage in groups. With a negative charge in the electric field was transfected into RPE cell layer, reverse electrode set to be transfected into PR cell layer. Retina mounts were made on seven days after transfection and the fluorescence of EGFP was photographed by fluorescent microscope. The expression of EGFP mRNA and protein were detected by reverse transcription polymerase chain reaction technique (RT-PCR) and Western blot.Results On seven days after transfection, in RPE subgroups, there were no specific fluorescence expressions in RPE cell layer and retina mounts of control eyes, while there were fluorescence expressions in experimental eyes. Western blot showed that the grayscale ratio of EGFP protein and beta;actin protein bands rose with the increased voltage. RT-PCR showed that each group produced positive amplification bands, and the relative ratio of gray level of EGFP mRNA and GADPH mRNA amplified bands gradually increased with the increased voltage.Conclusion Electroporation is an effective method for gene delivery into RPE cells in vivo.
ObjectiveTo analyze the subfoveal choroidal thickness in retinitis pigmentosa (RP) patients and to evaluate the correlation between the subfoveal choroidal thickness (SCT) and visual function. MethodsTotally 42 RP patients (84 eyes) and 49 age and diopter-matched normal controls (98 eyes) were enrolled in this study. All the patients were taken the enhanced depth imaging technique of optical coherence tomography (EDI-OCT) examination for the measurement of the SCT. The covariate analysis was used to analyze the interaction effect between age and group. Then the SCT was amended. The RP patients were examined by 30°visual field test (T32 or LVC program) and electroretinogram (ERG) test. 32 eyes examined by T32 program, 52 eyes examined by LVC program. The waveform of ERG, mean sensitivity (MS) and mean defect (MD) were recorded. The relationship of SCT, MS and MD were analyzed by Pearson correlation analysis. ResultsThe SCT of RP patients and controls were (223.12±69.59), (288.29±52.36) μm. The covariate analysis of covariance with different age group interaction was not statistically significant (F=1.619, P=0.205), as amended SCT of RP patients and controls were (217.34±6.60), (293.20±6.00) μm, respectively. The SCT was decreased in RP patients (t=7.042, P < 0.001). Among 84 eyes, bright cone response weaken in 35 eyes, scotopic rod response weaken in 31 eyes. The difference of SCT in different ERG waveform was not significant (t=-0.976, -1.584; P=0.332, 0.117). The MS and MD of 32 eyes using T32 program were (9.05±6.42), (18.84±6.30) dB, the SCT was (209.83±71.48) μm; the MS and SCT of 52 eyes using LVC program were (7.14±5.03) dB and (228.32±66.32) μm. The SCT was related to MS (r=0.494, P=0.003) and MD (r=-0.448, P=0.009) in eyes using T32 program. There was no correlation between SCT and MD in eyes using LVC program (r=-0.232, P=0.095). ConclusionsThe SCT of RP patients is thinner than that of normal controls. The SCT of RP patients is related to MS and MD of T32 program, but not correlated to ERG waveform and MS of LVC program.
ObjectiveTo observe the gene mutations and clinical phenotypes in patients with Usher syndrome type 2 (USH2) and retinitis pigmentosa (RP).Methods From August 2018 to January 2019, 4 patients and 11 normal family members from 3 families of USH2 and RP who visited Henan Eye Hospital were enrolled in the study. Detailed medical history was obtained and visual acuity, fundus color photography, OCT, visual field, full field ERG examination were performed. Among the three families, pedigree 1 was diagnosed with USH2, pedigree 2 and pedigree 3 were diagnosed with RP. The peripheral venous blood of patients and their family members were collected, and the whole genomic DNA was extracted. Targeted capture next generation sequencing analysis was performed on these members, and Sanger sequencing and family co-segregation were verified.ResultsIn the family F1, the proband had symptoms of RP and sensorineural deafness. Sequencing revealed two heterozygous frameshift variants: c.13877-13880 del AGAC (p. Q4626P) in exon 64 and c.798 del T (p. F266L) in exon 5 of USH2A. Both patients of family 2 and 3 showed RP signs without deafness. Two heterozygous variants c.15178T＞C (p. S5060 P) in exon 70 and c.6986C＞A (p. P2329H) in exon 37, and a pathogenic heterozygous variant c.5836C＞T (p. R1946X) in exon 29 of USH2A were identified in family F2. A heterozygous missense variant c.14951C＞T (p. P4984L) in exon 68 and a variant c.11156G＞A (p. R3719H) in exon 57 of USH2A were found in family F3. The results of conservation analysis showed that the corresponding amino acid sites of USH2A p.Q4626P, p.F266L, p.S5060P, p.P2329H and p.P4984L were highly conserved in many species. Among these 7 pathogenic variants detected, M1-M4 and M6 were novel.ConclusionsMutation USH2A gene are the main cause of USH2 and non-syndromic RP. Different variants affect protein translation and synthesis, consequently causing different clinical phenotypes.
Retinitis pigmentosa (RP) is a group of hereditary blinding fundus diseases caused by abnormalities in photoreceptors of the retina. RP is highly heterogeneous in hereditary and cdinical phenotypes. It can be divided into simple type RP and syndrome type RP. The main inheritance patterns are autosomal dominant, autosomal recessive inheritance and X-linked inheritance. With the popularization and clinical application of gene sequencing technology, more and more disease-causing genes have been discovered, and these genes are mainly expressed in photoreceptor cells and retinal pigment epithelial cell. ln-depth understanding of RP pathogenic genes not only provides a theoretical basis for RP diagnosis and genetic counseling, but also provides guidance for RP gene therapy.
Objective:To observe the intervention effect of the tetra methylpyraz ine on the rds mice with retinitis pigmentosa. Methods:A total of 84 rds mice were randomly divided into 2 groups, with 42 mice in each group. The mice in the experimental group underwent intraperitoneal cavity injection with hydrochlor i c tetramethylpyrazine (80 mg/kg, twice per day) at the date of birth and till 35 days after birth, whereas the normal saline was injected into the intraperito n eal cavity of rats in the control group. The mice were sacrificed 0, 3, 7, 14, 2 1, 28, 35 days after birth, and the eyeballs were enucleated for the routine pat hologic examination with the light microscope. The apoptosis of photoreceptor ce ll nuclei was detected by terminal deoxynucleotidyl transferasemediated dUTP n i ck endlabeling (TUNEL) technigue and the expression of bcl2 in retina was de tect by immunohistochemistry method. Results:The results of li ght microscopy s howed that the layer number of retinal photoreceptor cell nuclei with tetramethy lpyrazine treatment was increased 14, 21, 28, 35 days after the treatment compar ed with that in the control group（P＜0.01）. The results of electron-micro scope suggested that tetramethylpyrazine might reduce lesions in the photoreceptor cells and the destruction of the disc member, mitochondrion，and outer limiting me mbrane in the photoreceptor outer segment in rds mice. The apoptosis of the phot oreceptor cell nuclei reduced in rds mice 3, 7, 14, 21, 28 and 35 days after the treatment compared with that in the control group （P＜0.01）. The express ion of bcl-2 in the matrix of retinal photoreceptor cell nuclei and its inner and o u ter segments increased significantly in rds mice 3，7, 14, 21, 28 and 35 days af ter the treatment （P＜0.05）. Conclusions:Tetramethylpyra zine might reduce ret inal photoreceptor apoptosis by upregulating the expression of bcl-2 in the m at rix of retinal photoreceptor cell nuclei or its inner and outer segments in rds mice.
Objective To observe the effect of Minocycline on RP process of retinal pigmentary degeneration rd mice［C3H/HeN (Pde6brd-/rd-)］. Methods 40 rd mice were divided into ten groups randomly: 5 experimental groups and 5 control groups, 4 rd mice in each group. The experimental group received intraperitoneal injection of minocycline 22.5mg/kg while the control group received saline 10ml/kg every day from the postnatal day 1 (P1) . Mice were sacrificed at P1, P7, P14, P21 and P28 respectively. Eyeballs were enucleated to carry out histology observation and apoptosis cell detection. Meanwhile, to statistically analyze the number of retinal photoreceptor cells,the thickness of outer nuclear layer (ONL)and the number of apoptosis cells. Results （1）Photoreceptor cell began to apoptosis on P7, peaked on P14, and totally disappeared on P28. （2）No statistically significant differences were found of the number of photoreceptor cells and the thickness of ONL on P7 between the experimental group and the control group. (3) The number of photoreceptor cells and the thickness of ONL in the experimental were more than that in the control group at P14, P21, P28 respectively, the differences are statistically significant（Plt;0.05）. (4) The apoptotic cells on ONL were less in the experimental group than that in the control group on P7 and P14 respectively, the difference are statistically significant（Plt;0.05）. Conclusions Minocycline appears to protect photoreceptor cell from apoptosis in the early stage of the retinal degeneration mice, but it may not completely prevent RP from occurrence.