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 observe the changes of circumpapillary retinal nerve fiber layer (CP-RNFL) thickness and optic disk parameters in retinitis pigmentosa (RP) eyes.
MethodsProspective clinical case-control study. A total of 25 patients (42 eyes) with RP were in the RP group, and 42 age matched healthy subjects (84 eyes) in the control group. All subjects underwent optical coherence tomography (OCT) examination, in which 37 eyes with 3D optic disk scanning and 5 eyes with circle optic disk scanning. The parameters included average thickness of entire CP-RNFL, thickness of nasal, superior, temporal and inferior quadrant of CP-RNFL, disc area, disc cup area, rim area, cup/disc (C/D) area ratio, C/D horizontal diameter ratio, C/D vertical diameter ratio, disc cup volume and disc rim volume.
ResultsThe average thickness and the thickness of temporal and nasal quadrants of CP-RNFL in RP group were significantly thicker than the control group (t=2.27, 3.73, 6.44; P=0.027, 0.00, 0.00), while the thickness of inferior and superior areas were the same as control group(t=-1.49, -1.19; P=0.14, 0.24). The disc area, disc cup area, C/D area ratio, C/D horizontal diameter ratio, C/D vertical diameter ratio, disc cup volume in RP group were significantly bigger than control group (P < 0.05), while rim area and rim volume were not significant differences (t=1.75, 0.40; P=0.08, 0.59).
ConclusionIn comparison with the healthy subjects, the average thickness and temporal and nasal areas of CP-RNFL in RP eyes were thicker, and the disc area, disc cup area, C/D area ratio, C/D horizontal diameter ratio, C/D vertical diameter ratio, disc cup volume in RP eyes were bigger.
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)
ObjectiveTo identify the causative gene in a family affected with Usher syndrome (USH) with retinitis pigmentosa sine pigmento (RPSP) and to analyze the genotype-phenotype correlation.MethodsA retrospective clinical study. A 9-year-old girl with RPSP type 1F USH diagnosed in the ophthalmology clinic of Henan Provincial People's Hospital in November 2019 and her parents were included in the study. The patient had bilateral night blindness for more than 4 years, she suffered from hearing loss 7 years, and is currently binaural sensorineural deafness. The best corrected visual acuity in both eyes was 0.5+. There was showed no obvious pigmentation on the fundus. The visual acuity of the peripheral field of vision decreased. Optical coherence tomography showed that the outer layer of the peripheral retina became thinner and the ellipsoid band disappeared. On electroretinogram examination, the rod and cone system response was severely decreased. The clinical phenotype of the parents of the child were normal. The peripheral venous blood of the child and his parents were extracted, the whole genome DNA was extracted, the custom developed targeted capture kit (PS400) was used, and the next-generation sequencing technology was used to detect genetic mutations. The suspected pathogenic mutation sites were verified by Sanger; co-segregation was performed among family members. The pathogenicity of variants were evaluated according to the interpretation standards and guidelines of sequence variants. Bioinformatics techniques were used to assess the impact of variants on encoded proteins.ResultsThe results of genetic testing showed that the proband detected the PCDH15 gene c.4109dupA (p.K1370fs) (M1), c.17dupA (p.Y6_L7delinsX) (M2) compound heterozygous mutation sites, verified by Sanger sequencing, the mutations were in the family in a state of co-segregation. According to the evaluation of sequence variation interpretation standards and guidelines, M1 and M2 were pathogenic variants of the PCDH15 gene. M1 led to a complete change in the transmembrane structure of the encoded protein, and M2 caused the gene to only translate 6 amino acids, which predicted that the PCDH15 protein cannot be synthesized. According to the clinical phenotype, gene mutation pathogenicity and protein structure prediction, the final clinical diagnosis was PCDH15-related type 1F.ConclusionsPCDH15 genes c.4109dupA and c.17dupA are the pathogenic mutation sites of USH in this family. These compound heterozygous new mutations lead to the failure of normal synthesis of PCDH15 protein, which leads to ocular and ear manifestations.
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.
Objective
To detect and analyse the mutations in rhodopsin gene of members in a family affected by autosomal dominant retinitis pigmentosa (ADRP).
Methods
Using the polymerase chain reaction (PCR), we amplified exon 1-5 of rhodopsin gene in patients with ADRP,and analyzed it with direct sequence measuement.
Results
The Gly-182-Asp mutation in the rhodopsin gene was detected in most of affected members of this ADRP family, but no mutation was detected in two affected members and the control ones.
Conclusion
We cannot regard the Gly-182-Asp mutation in the rhodopsin gene as the pathagenic factor of the ADRP family. It is likely there is a new gene next to the rhodopsin gene.
(Chin J Ocul Fundus Dis, 2002, 18: 256-258)
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.
With the intensification of population aging and the popularity of electronic products, the incidence of retinal diseases continues to rise, and their complex pathogenesis seriously restricts the development of effective treatment strategies. Zebrafish has become an important model animal for ophthalmic research, especially for retinal disease research, due to its unique biological advantages. This article aims to systematically review the current application status and prospects of zebrafish models in various retinal disease research, broaden future research ideas, and provide new perspectives for the prevention and treatment of retinal diseases. This article first elaborates on the unique advantages of zebrafish as a model animal, including easy feeding, transparent embryos, rapid development of the visual system, high homology with human genes, and strong retinal regeneration ability. Subsequently, we reviewed the research and application progress of zebrafish models, focusing on various hereditary and non-hereditary retinal diseases, including diabetic retinopathy, retinopathy of prematurity, retinitis pigmentosa, rod-cone cell dystrophy, Leber congenital amaurosis, congenital static night blindness, choroidal deletion, and Budd Beeder syndrome. Studies have confirmed that a large number of zebrafish models simulating the pathological characteristics of human retinal diseases have been constructed successfully using genetic techniques such as CRISPR/Cas9 gene editing, TALEN targeted modification, chemical induction, and microinjection. These models not only effectively reproduce the clinical phenotype of retinal diseases but also play an irreplaceable role in elucidating the functions of pathogenic genes, revealing signal pathway disorders, and analyzing the mechanisms of cell death and regeneration. Additionally, the zebrafish model has shown great potential in drug screening and efficacy evaluation. These studies indicate that the zebrafish model is an ideal tool for in-depth analysis of the pathogenesis of retinal diseases, promoting precision medicine and new drug development, and has broad application prospects in the future.
Objective To observe the characteristics of fundus autofluorescence (AF) in short wavelength AF (SW-AF) and Near Infrared AF (NIR-AF), and their relationship with visual fields. Methods Twelve patients (24 eyes) with primary RP were enrolled in this study. The patients included nine males (18 eyes) and three females (six eyes). The patients aged from 15 to 69 years, with a mean age of (35.33plusmn;15.03) years. All the patients were examined for color photography, SW-AF, NIR-AF, visual fields and optical coherence tomography examination. Results There were hyper-AF ring of varying sizes in posterior pole by SW-AF and NIR-AF examinations. The area of hypo-AF which located in SW-AF hyper-AF ring had a positive correlation with the area of hyper-AF in the NIR-AF (r=0.662，P＜0.05). OCT showed that outside the hyper-AF ring, there were disconnected inner segment/outer segment (IS/OS) junction and external limiting membrane, and thinned outer nuclear layer and retinal pigment epithelium. Peripheral retinal osteocytes-like pigmentation showed non fluorescence in SW-AF and NIR-AF. The plaque-like area showed mottled and low fluorescence examined by SW-AF. SW-AF hyper-AF ring had a positive correlation with visual fields (r=0.492，P＜0.05). Conclusions The area of hypo-AF inside of the SW-AF hyper-AF ring is related to visual fields in RP patients. The retinal structures in the hypo-AF area inside of the SW-AF hyper-AF ring, and in the NIR-AF hyper-AF region are normal.
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.
