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.
ObjectiveTo observe the clinical characteristics of primary retinitis pigmentosa (RP) complicated with glaucoma.MethodsA retrospective clinical study. From June 2008 to March 2020, the diagnosis of primary RP were included in the diagnosis confirmed by the eye examination of West China Hospital of Sichuan University included 4794 eyes of 2432 patients. Among them, 4679 eyes (97.2%, 2364/2432) were in 2364 cases with RP alone, and 115 eyes were in 68 cases with RP combined with glaucoma (2.80%, 68/2432). All affected eyes underwent best corrected visual acuity (BCVA) and intraocular pressure examination. The BCVA examination was carried out using the international standard visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistics. The 67 eyes of 40 patients with RP and glaucoma with complete follow-up data were analyzed to observe the proportion of different glaucoma types, logMAR BCVA, intraocular pressure and other clinical characteristics, as well as treatment methods and post-treatment intraocular pressure control. After treatment, the intraocular pressure ≤21 mm Hg (1 mm Hg=0.133 kPa) was regarded as intraocular pressure (IOP) control; ＞21 mm Hg was regarded as uncontrolled IOP.ResultsAmong the 67 eyes of 40 cases with complete follow-up data, 5 cases (7 eyes) with primary open-angle glaucoma (10.45%, 7/67), 56 cases (58 eyes) with angle-closure glaucoma (ACG) (86.57%, 58/67), 4 cases (4 eyes) with neovascular glaucoma (5.97%, 4/67), 2 of them had both ACG and neovascular glaucoma. Among 58 ACG eyes, 17 eyes were acute ACG (25.37%, 17/67), 21 eyes were chronic ACG (31.34%, 21/67), and 2 eyes were suspicious angle closure (2.99%, 2/67), lens dislocation secondary to angle-closure glaucoma in 8 eyes (11.94%, 8/67), chronic angle-closure glaucoma after anti-glaucoma surgery, intraocular lens shift in 5 eyes (7.46%, 5/67), 5 eyes (7.46%, 5/67) secondary to glaucoma with true small eyeballs. The logMAR BCVA 3.50 of the affected eye,＜3.50-＞2.00, ≤2.00-≥1.30,＜1.30-＞1.00, ≤1.00-0.52,＜0.52 were 9 (13.43%, 9/67), 30 (44.78%, 30/ 67), 7 (10.45%, 7/67), 4 (5.97%, 4/67), 11 (16.42%, 11/67), 6 (8.96%, 6/67) eyes, which correspond to mean intraocular pressure were 32.31±11.67, 30.15±14.85, 28.17±13.19, 31.50±17.25, 18.71±8.85, 14.12±4.25 mm Hg. Among 67 eyes, 37eyes (55.22%, 37/67), 18eyes (26.86%, 18/67), and 6 (8.96%, 6/67) eyes underwent surgery, medication alone, and peripheral iris laser perforation treatment, respectively. The treatment of 6 eyes was abandoned (8.96%, 6/67). Malignant glaucoma occurred in 3 eyes (8.11%, 3/37) after the operation, all of which were after trabeculectomy of the ACG eye. After treatment, intraocular pressure was controlled in 37 eyes (55.22%, 37/67), 19 eyes were not controlled (28.36%, 19/67), and 11 eyes were lost to follow-up (16.42%, 11/67).ConclusionsThe incidence of glaucoma in patients with primary RP is 2.80%. ACG is more common, and the combined lens dislocation or intraocular lens shift is more common.
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.
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.
ObjectiveTo explore the light response, retinal inflammation and apoptosis of the retinal ganglion cells (RGCs) 1 year after the new type of channelrhodopsin PsCatCh2.0 was transfected into the retina of rd1 mice. MethodsTwenty-four male rd1 mice were randomly divided into rd1 experimental group and rd1 control group, 12 mice in each group. 1.5 μl of recombinant adeno-associated virus (rAAV)2/2-cytomegalovirus (CMV)-PsCatCh2.0-enhanced green fluorescent protein (EGFP) was injected into the vitreous cavity 1 mm below the corneoscleral limbus of mice in the rd1 experimental group, and the same dose of recombinant virus was injected 2 weeks later at temporal side 1 mm below the corneoscleral limbus. One year after virus injection, the light response of RGCs expressing PsCatCh2.0 was recorded by patch clamp technique; the expression of PsCatCh2.0 in the retina was evaluated by immunofluorescence staining; the transfection efficiency of recombinant virus was evaluated by the transfection efficiency of virus and the number of RGCs. Hematoxylin-eosin staining was performed to measure the inner retinal thickness. Western blotting was used to detect the protein expression of nuclear factor (NF)-κB p65 in retina; real-time quantitative polymerase chain reaction was used to detect the relative expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and Bax mRNA. Terminal deoxynucleotidyl transferase kit was used to observe the apoptosis of retinal cells in each group of mice. ResultsOne year after the intravitreal injection of recombinant virus, PsCatCh2.0-expressing RGCs can still generate 30 pA photocurrent. The virus PsCatCh2.0-EGFP was mainly transfected into RGCs, and partly transfected into amacrine cells, almost no transfection was seen in bipolar and horizontal cells. There were no significant differences in the number of RGCs and thickness of the inner retina between the rd1 experimental group and the rd1 control group (F=14.35, 0.05; P＞0.05), while the rd1 experimental group NF-κB p65 protein expression, TNF-α and IL-6 mRNA quantification were significantly lower than those of rd1 control group (F=4.61, 5.91, 5.78; P＜0.05). The number of red fluorescent apoptotic cells in the retina of mice in the rd1 experimental group was less than that in the rd1 control group, and the Bax mRNA expression was lower than that in the rd1 control group, and the difference was statistically significant (F=7.52, P＜0.01). ConclusionOne year after intravitreal injection of recombinant virus, the PsCatCh2.0 expressing RGCs can still generate photocurrent. Long term transfection and expression of PsCatCh2.0 has no obvious cytotoxic effect on RGCs, nor it increases the inflammatory effect of the retina of rd1 mice with retinal degeneration.
ObjectiveTo investigate the current status of research in gene therapy for retinitis pigmentosa (RP) from 2005 to 2024. MethodsThe literature related to gene therapy for RP included in the Web of Science Core Collection dataset from January 1, 2005 to September 15, 2024 was retrieved and screened. The bibliometrix package of R software was used to analyze the annual trend of the number of publications, citation frequency, distribution of countries/regions of the literature, and distribution of journals containing the articles. CiteSpace software was used to perform keyword clustering analysis and the keywords bursts analysis. ResultsA total of 209 articles were included. There was an overall fluctuating upward trend of annual publications from 2005 to 2024, with the highest number of publications in 2023 at 26 (12.4%, 26/209), and the lowest number of publications in 2006 at 2 (0.9%, 2/209). There was an overall increasing trend in the frequency of citations to relevant literature. Corresponding authors from the United States had the highest total number of publications with 98 (46.9%, 98/209). Among authors, Hauswirth from the University of Florida, USA, had the most with 25 (12.0%, 25/209). Among institutions, Columbia University, USA, had the most with 55 (26.3%, 55/209). Among journals, Mol Ther had the most with 25 (12.0%, 25/209), and it had the highest 2023 impact factor of 12.1. Keyword clustering analysis yielded eight valid clusters, namely #0 P23H, #1 AAV, #2 PDE6B, #3 CRB1, #4 RPGR, #5 antisense oligonucleotide, #6 NR2E3, and #7 NRL, which intersected with each other with good continuity. The keywords bursts analysis showed that the keyword with the longest emergence time was RNAi, followed by PDE and PDE6. USH2A, CRB1, CRISPR Cas9, base editing, and ORF15 were keywords that emerged in recent years and were continuously studied. ConclusionsRP gene therapy research literature has shown an increasing trend from 2005 to 2024, with the highest number of publications from research organizations and scholars in the United States. Currently, studies focus on RHO, PDE6B, CRB1, RPGR, NR2E3, and NRL gene. In recent years, there has been a gradual increase in studies on USH2A, CRB1 genes, and the RPGR ORF15 region. CRISPR Cas9 and base editing gene therapy strategies are being developed.
Retinitis pigmentosa (RP) is an inherited retinal disease characterized by degeneration of retinal pigment epithelial cells. Precision medicine is a new medical model that applies modern genetic technology, combining living environment, clinical data of patients, molecular imaging technology and bio-information technology to achieve accurate diagnosis and treatment, and establish personalized disease prevention and treatment model. At present, precise diagnosis of RP is mainly based on next-generation sequencing technology and preimplantation genetic diagnosis, while precise therapy is mainly reflected in gene therapy, stem cell transplantation and gene-stem cell therapy. Although the current research on precision medicine for RP has achieved remarkable results, there are still many problems in the application process that is needed close attention. For instance, the current gene therapy cannot completely treat dominant or advanced genetic diseases, the safety of gene editing technology has not been solved, the cells after stem cell transplantation cannot be effectively integrated with the host, gene sequencing has not been fully popularized, and the big data information platform is imperfect. It is believed that with the in-depth research of gene sequencing technology, regenerative medicine and the successful development of clinical trials, the precision medicine for RP will be gradually improved and is expected to be applied to improve the vision of patients with RP in the future.
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.
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.
ObjectiveTo investigate and analyze the relationship between genotype and phenotype in patients with early-onset high myopia (eoHM) associated with hereditary eye diseases. MethodsA family-based study was conducted among 30 families diagnosed with eoHM at Department of Ophthalmology of People's Hospital of Ningxia Hui Autonomous Region from January 2022 to June 2023. Seven families (23.3%, 7/30), all probands, and their 14 parents were included. These seven families were unrelated. Detailed patient and family histories were collected. All participants underwent comprehensive ophthalmic examinations, including best-corrected visual acuity, color vision testing, fundus color photography, optical coherence tomography, fluorescein fundus angiography, and fundus autofluorescence imaging. Full-field electroretinography was performed in four cases. Peripheral venous blood samples were collected from patients and their parents for whole-genome DNA extraction and whole-exome sequencing. Potential pathogenic variants were identified, and their pathogenicity was analyzed and confirmed by Sanger sequencing. The pathogenicity of newly discovered gene variants was evaluated according to the guidelines of the American College of Medical Genetics and Genomics (ACMG). Literature on previously reported eoHM associated with hereditary eye diseases was reviewed to analyze the relationship between variant genes and clinical phenotypes. ResultsAmong the seven families, three exhibited X-linked inheritance, two showed autosomal recessive inheritance, and two demonstrated autosomal dominant inheritance. All the patients were male. Among the seven patients, one case each was identified with congenital stationary night blindness (CSNB), Bornholm eye disease, X-linked retinitis pigmentosa (XL-RP), cone-rod dystrophy, Knobloch syndrome, familial exudative vitreoretinopathy (FEVR), and Stickler syndrome. Genetic testing revealed nine gene variants highly correlated with the observed phenotypes. The genetic testing results revealed that all patients were found to carry nine gene variants highly associated with the phenotype, including: a hemizygous missense variant NYX c.647A>T (p.N216I) (M1), an OPN1LW LIAVA haplotype variant (M2), a hemizygous frameshift variant RPGR c.3096_3097del (p.E1033RfsTer45) (M3), compound heterozygous variants TTLL5 c.1588_1589del (p.L531EfsTer24) and c.850G>C (p.D284H) (M4, M5), compound heterozygous variants COL18A1 c.2118dup (p.G707RfsTer23) and c.3523_3524del (p.L1175VfsTer72) (M6, M7), a heterozygous missense mutation FZD4 c.1499C>T (p.T500I) (M8), and a heterozygous frameshift variant COL11A2 c.966dup (p.T323HfsTer19) (M9). Among them, M2, M4, M5, M8 and M9 were newly discovered mutation sites, and M1, M3, M6 and M7 were known mutation sites. According to the classification standards and guidelines of genetic variation issued by ACMG, M2, M3, M4, M6, M7, and M9 were judged to be pathogenic variants, while M1, M5, and M8 were of unknown clinical significance. Through literature review, it was found that eoHM was more common among the clinical phenotypes of 4 types of hereditary retinal diseases, including CSNB, Stickler syndrome, FEVR and XL-RP. ConclusioneoHM is intricately associated with inherited eye diseases and may serve as the earliest indicator of such conditions.
