It is clear that genetic background contributes to the development and progression of diabetic retinopathy (DR). However, the identification of susceptibility loci through candidate gene approaches, linkage disequilibrium analysis of case-control data and genome wide association study is still in its infancy and faces many challenges due to the complexity of the disease itself. China has rich resources of clinical samples. In order to facilitate elucidating the susceptibility genes of DR in China, we look forward multi-disciplinary, multi-regional collaboration studies integrating novel technologies, such as proteomics, metabolomics and next-generation sequencing to analyze gene-gene and gene-environment interaction factors comprehensively.
Inherited eye disease is a heterogeneous group of eye disorders caused by genetic defects, which has many genetic characteristics, such as multiple inheritance modes and numerous gene variation types. Over the past few decades, genetic testing has improved significantly, with more and more known disease-causing gene variants identified. With the rapid development of high-throughput sequencing technology, clinical diagnosis and treatment of eye genetic diseases have been accelerated, and molecular diagnosis of eye genetic diseases has become an important step in accurate diagnosis and treatment. How to correctly select and evaluate each kind of genetic testing technology, reasonably standardize the use of genetic testing technology, and provide patients with more accurate genetic counseling are problem that clinicians need to seriously consider.
Choroideremia (CHM) is a rare inherited eye disease that leads to blindness. It is caused by pathogenic variants in the CHM gene and exhibits X-linked recessive inheritance. Affected males present with progressively worsening night blindness, visual field loss, and decreased central vision, which can cause blindness in middle age. Although female carriers typically exhibit mild symptoms, it is essential to understand their clinical features for early diagnosis of patients as well as genetic counseling of family members. Currently, the recognition and diagnosis rates of CHM among ophthalmologists in various regions and levels of hospitals in China still need to be improved. A standardized clinical pathway is needed to meet the diagnostic and treatment needs of patients. Led by the the Chinese Hereditary Ocular Disease Diagnosis and the Treatment Group and the Chinese Hereditary Ocular Disease Alliance, based on existing evidence both domestically and internationally, the Expert consensus on diagnosis and treatment of choroideremia (2024) has been compiled, systematically and comprehensively elaborating on the standardized clinical pathways for CHM. Interpreting the key points of this consensus will help highlight its core points and ideas, enhancing the standardization and effectiveness of the diagnosis and treatment of CHM by ophthalmologists from all levels of hospitals.
Objective To make the diagnosis of a pedigree of X-linked congenital stational night blindness(CSNB) and to identify the disease-causing gene. Methods Clinical examination and family analysis were made. Venous blood was drawn from 5 affected and 16 unaffected individuals from the family. Genomic DNA was extracted. The locus of the candidate gene was mapped by linkage study. Mutation was screened by polymerase chain reaction (PCR) of the candidate gene exons and flanked introns. The PCR products are directly sequenced. The healthy people in and out of the family who were selected according to certain standards were as the control. Results A Chinese family with X-linked complete congenital stationary night blindness (CSNB1) was diagnosed. A missense mutation A772C (T258P) in exon 2 of NYX gene was identified in all affected patients and all female carriers were heterozygous. This mutation was neither found in normal family members nor among 110 unrelated normal controls. Conclusion A novel mutation of NYX gene with threonine to proline change is responsible for this Chinese CSNB1 family. (Chin J Ocul Fundus Dis, 2007, 23: 184-188)
ObjectiveTo observe and analyze the rate of visual acuity progression and binocular symmetry in patients with choroideremia (CHM). MethodsA single-center retrospective longitudinal cohort study. From April 2009 to August 2022, 38 eyes of 19 patients diagnosed with CHM through clinical and genetic testing at the Department of Ophthalmology, Peking Union Medical College Hospital, were included in this study. All patients underwent at least 2 follow-up visits with a minimum interval of 1 year between visits, and binocular best-corrected visual acuity (BCVA) results were recorded at each follow-up visit. Decimal visual acuity was converted into logarithm of the minimum angle of resolution (logMAR) for analysis. The patient group consisted of 19 males from 16 unrelated families. The age at initial visit was (39.52±13.24) years, with a (2.63±1.61) follow-up visits over a duration of (4.95±2.68) years. A total of 50 binocular BCVA data were included. Annual progression rate of visual acuity was calculated based on longitudinal and cross-sectional data. Spearman correlation coefficient and Bland-Altman method were used to evaluate the binocular symmetry. ResultsThe rate of visual acuity progression was (0.095±0.148) logMAR units/year based on longitudinal data and (0.018±0.009) logMAR units/year based on cross-sectional data. The binocular symmetry for BCVA of the baseline values was strong; however, the binocular symmetry of progression rates for BCVA was moderate. Spearman correlation analysis showed that binocular symmetry in baseline BCVA was high (r=0.881, P＜0.001). The symmetry of binocular vision progression rates based on longitudinal data was moderately symmetric (r=0.528, P=0.020). Bland-Altman analysis showed that 94.7% of binocular baseline BCVA differences were within 95% confidence interval (CI) of 95% limit difference (LOA), indicating good symmetry of binocular baseline BCVA. The number of binocular BCVA progression rate differences within 95%CI of 95%LOA was 89.5%, suggesting moderate symmetry in binocular BCVA progression rate. The results of Spearman correlation coefficient and Bland-Altman analysis of binocular symmetry were basically consistent. ConclusionsThe rate of visual acuity progression of patients with CHM based on longitudinal and cross-sectional data is (0.095±0.148) and (0.018±0.009) logMAR units/year, respectively. Cross-sectional data from patients of different ages should not be used to infer the progression rate of the natural history. Binocular eyes with highly symmetrical baseline visual acuity may differ in the rate of visual acuity progression.
Objectives To observe the clinical characteristics of Leber congenital amaurosis (LCA) and analyze the features to differentiate LCA from other similar disorders.Methods Prospective study of 15 LCA patients which include 10 males and 5 females, aged from 2 to 31 years with the mean age 13.6 years. Medical history, family history, perinatal conditions, as well as complete ocular evaluations were well documented. Among the subjects, 12 patients underwent optometry check, 10 patients underwent ERG and 8 patients had OCT testing. Results All of the patients had nystagmus and sluggish pupillary reflex. The visual acuity distributed from light perception to 0.1. Fivepatients (33.3%) were presented with photophobia, while 7 patients (46.7%) had nyctalopia. Among 12 cases underwent refraction examination, 6 patients (50%) had spherical equivalent of ge;+5D；1 patient（8.3%）had spherical equivalent of ge;+5D; 2 patients (16.7%) had bilateral mild to moderate hyperopia；1 patient (8.3%) had one emmertropic eye and one mild myopic eye; 2 patients (16.7%) had moderate to high myopia. Eight patients (53.3%) had enophthalmus,4 patients (26.7%) had oculodigital sign. All of the 10 patients underwent ERG showed extinguished waveform. Under OCT assesement, 7 patients had decreased fovea thickness; 1 patient had increased fovea thickness, complicated by epiretinal membrane; mild abnormality of microstructure of the retina with diminished and disrupted IS/OS hyperreflectivity were found in 2 cases；while more pronounced disarrangement of the retinal layers were found in 6 cases，inner layers were better reserved in all patients.Conclusions Severe visual impairment or blindness, nystagmus, pupillary reflex, extinguished ERG and hyperopia are main clinical characteristics of LCA.