To assess the long-term safety of orthokeratology (ortho-k) in myopic children by evaluating changes in corneal endothelial morphology and central corneal thickness (CCT) after prolonged ortho-k lens wear.

This study included 65 myopic children (130 eyes). The ortho-k group comprised 39 children who had worn ortho-k lenses for more than 10y. The control group included 26 children who wore single-vision spectacles for myopia correction. Clinical data and adverse events were documented throughout the follow-up period. Endothelial cell density (ECD), coefficient of variation (CV) of cell area, percentage of hexagonal cells (%SIX), and CCT were measured at baseline and at the final follow-up visit.

The 39 participants (18 males, 21 females) enrolled in the ortho-k group completed the 10-year follow-up examinations successfully. The ages ranged from 7 to 12 (9.24±1.26)y. In the control group, 26 participants (13 males, 13 females) were successfully recalled and completed their 10^th year examinations. The ages ranged from 7 to 12 (9.62±1.68)y. In the ortho-k group, ECD was 3119.86±202.07 cells/mm² at baseline and 3057.42±264.52 cells/mm² at the 10-year follow-up (P=0.058). CV was 30.78%±6.70% and 32.45%±7.87% (P=0.053). %SIX was 62.23%±13.07% and 60.31%±11.59% (P=0.234). CCT decreased by 8±4 μm at the 6-month visit and remained stable thereafter (538.85±43.61 μm at 6mo vs 540.78±41.44 μm at 10y, P=0.528). At the 10-year follow-up, no significant between-group differences were observed in ECD, CV, %SIX, or CCT (all P>0.05).

This 10-year retrospective study demonstrates that long-term ortho-k lens wear has no significant adverse effects on corneal endothelial morphology or CCT compared with spectacle wear. Ortho-k shows excellent long-term safety with regard to corneal endothelial parameters and CCT, comparable to that of conventional spectacle correction in myopic children.

To analyze the pathogenicity and clinical features of patients in a consanguineous cone-rod dystrophy (CRD) family due to heterozygous variants in the GUCY2D gene.

Whole exome sequencing was used to screen for pathogenic genes and candidate pathogenic variants were obtained by bioinformatics analysis. Sanger sequencing was used for validation and familial co-segregation analysis to determine pathogenic variants. Pymol software was applied to produce a 3D structure image of the protein to analyze the structural and functional alterations of the protein. The pathogenicity of genetic variants was evaluated according to ACMG guidelines.

The chief clinical symptoms of this proband included obvious visual impairment, protanopia and deuteranopia, peripheral punctate pigment, arteriolar attenuation, structural and functional abnormalities revealed by optical coherence tomography (OCT) and electroretinography (ERG) including thinning of the outer retinal layer, a discontinuous external limiting membrane (ELM) and ellipsoid zone (EZ), granular hyperreflective projections between the retinal pigment epithelium and the interdigitation zone, severe attenuation of photopic responses with mild reduced scotopic responses. Whole-exome sequencing revealed that the proband carried a heterozygous variant of the GUCY2D gene: c.2512C>T: p.Arg838Cys. Three-dimensional molecular structure analysis of the protein revealed that amino acid 838 was mutated from polar positively charged arginine to polar uncharged cysteine, and the spatial structure of the protein changed greatly. Sanger sequencing co-segregation analysis confirmed that such a variant was detected in neither the phenotypically normal parents nor the daughter of the proband, which was presumed to be a de novo one. The variant was determined to be pathogenic according to ACMG guidelines. The heterozygous variant at the same site was detected in the abnormal proband’s son with moderate attenuation of photopic electroretinographic responses and normal scotopic electroretinographic responses, supporting autosomal dominant inheritance.

The de novo variant causing atypical autosomal dominant CRD is identified in a Chinese consanguineous family and this variant passes through this family in an autosomal dominant mode of inheritance, revealing the complex diversity and unpredictability of the inheritance mode for common single-gene genetic disease.

To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery.

In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients.

The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (r_Han=0.48, r_Uyghur=0.44, P<0.001), while AL was negatively correlated with Kf (r_Han=-0.42, r_Uyghur=-0.64, P<0.001) and Ks (r_Han= -0.38, r_Uyghur=-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (r_Han=0.89, r_Uyghur=0.93, P<0.001).

There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.