Initial screening for occult congenital ectopia lentis based on ocular biological parameters in preschool children.

BACKGROUND: This study aimed to identify an initial screening tool for congenital ectopia lentis (CEL) by comparing ocular biological parameters in children with myopia. METHODS: A retrospective case-control study was conducted at one tertiary referral centre, from October 2020 to June 2022. Axial length (AL), corneal curvature (CC), refractive astigmatism (RA), corneal astigmatism (CA), internal astigmatism (IA), the difference between the axis of RA and CA [AXIS(RA-CA)], white-to-white corneal diameter (WTW), and axial length-corneal radius ratio (AL/CR) were compared in 28 eyes of CEL patients, and 60 eyes of myopic patients matched for age and refraction. The spherical equivalent of each eye was < -3.00 D. Area under the curve (AUC) of the receiver operating characteristic curves were calculated. RESULTS: The differences in RA, AL, mean keratometry (Kmed), maximum keratometry (Kmax), minimum keratometry (Kmin), CA, IA, AXIS(RA-CA), WTW, and AL/CR between the CEL and myopic groups were statistically significant (p < 0.05; p < 0.001; p < 0.001; p < 0.001; p < 0.001; p < 0.05; p < 0.001; p < 0.001; p < 0.001; p < 0.001, respectively). In logistic regression analysis RA, IA, AXIS(RA-CA), and AL/CR were significantly associated with CEL (p < 0.05). AUCs for RA, IA, AXIS(RA-CA), and AL/CR were 0.694, 0.853, 0.814, and 0.960, respectively. AUCs for AL/CR in SE< -6.00 D subgroup was 0.970, and 0.990 in -6.00 D ≤ SE < -3.00 D group. An AL/CR < 3.024 was the optimal cut-off point differentiating the CEL and control groups (sensitivity, 92.9%; specificity, 88.30%). CONCLUSIONS: A smaller AL/CR could identify CEL in children with myopia. An AL/CR cut-off value of 3.024 may be the most sensitive and specific parameter for the differential diagnosis of CEL in patients with mild to high myopia.

Somatostatin signalling promotes the differentiation of rod photoreceptors in human pluripotent stem cell-derived retinal organoid.

OBJECTIVES: Stem cell-derived photoreceptor replacement therapy is a promising strategy for the treatment of retinal degenerative disease. The development of 3D retinal organoids has permitted the production of photoreceptors. However, there is no strategy to enrich a specific photoreceptor subtype due to inadequate knowledge of the molecular mechanism underlying the photoreceptor fate determination. Hence, our aim is to explore the uncharacterized function of somatostatin signalling in human pluripotent stem cell-derived photoreceptor differentiation. MATERIALS AND METHODS: 3D retinal organoids were achieved from human embryonic stem cell. The published single-cell RNA-sequencing datasets of human retinal development were utilized to further investigate the transcriptional regulation of photoreceptor differentiation. The assays of immunofluorescence staining, lentivirus transfection, real-time quantitative polymerase chain reaction and western blotting were performed. RESULTS: We identified that the somatostatin receptor 2 (SSTR2)-mediated signalling was essential for rod photoreceptor differentiation at the precursor stage. The addition of the cognate ligand somatostatin in human 3D retinal organoids promoted rod photoreceptor differentiation and inhibited cone photoreceptor production. Furthermore, we found that the genesis of rod photoreceptors was modulated by endogenous somatostatin specifically secreted by developing retinal ganglion cells. CONCLUSIONS: Our study identified SSTR2 signalling as a novel extrinsic regulator for rod photoreceptor fate determination in photoreceptor precursors, which expands the repertoire of functional signalling pathways in photoreceptor development and sheds light on the optimization of the photoreceptor enrichment strategy.

A Novel System for Measuring Pterygium's Progress Using Deep Learning.

Pterygium is a common ocular surface disease. When pterygium significantly invades the cornea, it limits eye movement and impairs vision, which requires surgery to remove. It is medically recognized that when the width of the pterygium that invades the cornea is >3 mm, the patient can be treated with surgical resection. Owing to this, this study proposes a system for diagnosing and measuring the pathological progress of pterygium using deep learning methods, which aims to assist doctors in designing pterygium surgical treatment strategies. The proposed system only needs to input the anterior segment images of patients to automatically and efficiently measure the width of the pterygium that invades the cornea, and the patient's pterygium symptom status can be obtained. The system consists of three modules, including cornea segmentation module, pterygium segmentation module, and measurement module. Both segmentation modules use convolutional neural networks. In the pterygium segmentation module, to adapt the diversity of the pterygium's shape and size, an improved U-Net++ model by adding an Attention gate before each up-sampling layer is proposed. The Attention gates extract information related to the target, so that the model can pay more attention to the shape and size of the pterygium. The measurement module realizes the measurement of the width and area of the pterygium that invades the cornea and the classification of pterygium symptom status. In this study, the effectiveness of the proposed system is verified using datasets collected from the ocular surface diseases center at the Affiliated Eye Hospital of Nanjing Medical University. The results obtained show that the Dice coefficient of the cornea segmentation module and the pterygium segmentation module are 0.9620 and 0.9020, respectively. The Kappa consistency coefficient between the final measurement results of the system and the doctor's visual inspection results is 0.918, which proves that the system has practical application significance.

RNA Interference Targeting Connective Tissue Growth Factor Inhibits the Transforming Growth Factor- ß 2 Induced Proliferation in Human Tenon Capsule Fibroblasts.

Purpose. This study was to determine the effect of CTGF-small interfering RNA (siRNA) on TGF- ß 2-induced proliferation in human Tenon capsule fibroblasts (HTFs). Methods. HTFs were transfected with four of CTGF-siRNAs separately for screening of gene silencing efficacy that was determined by transcript level measured by quantitative real-time PCR (qRT-PCR). Recombinant TGF- ß 2 was added into the culture to stimulate the proliferation of HTFs. The gene silencing efficacy of the siRNAs was evaluated by qRT-PCR and immunofluorescence of CTGF transcript and protein levels. The viability of HTFs was determined by cell counting kit-8 (CCK-8). FCM was used to assess cell cycle after CTGF-siRNA transfection. Results. The expression of CTGF and proliferation of HTFs were increased significantly by TGF- ß 2 stimulation. The transfection of CTGF-siRNA abolished the upregulation of CTGF and cell proliferation induced by TGF- ß 2. The analysis of cell cycle indicated that CTGF-siRNA treatment stimulated cells from S phase to G0/G1 phase in comparison with the inverse physiologic function of TGF- ß 2. Conclusion. CTGF targeting siRNA could effectively suppress the expression of CTGF and attenuate the proliferation of HTFs. The siRNA approach may provide a therapeutic option for eliminating filtration bleb scarring after glaucoma filtration surgery (GFS).

RNA Interference Targeting Snail Inhibits the Transforming Growth Factor ß 2-Induced Epithelial-Mesenchymal Transition in Human Lens Epithelial Cells.

Epithelial-msenchymal transition (EMT) contributes to posterior capsule opacification (PCO) type of cataract. Transcription factors Snail is a key trigger of EMT activated by transforming growth factor ß (TGF ß ). This study was done to investigate the effect of Snail targeting siRNA on TGF ß 2-induced EMT in human lens epithelial cells. TGF ß 2 treatment of cultured human epithelial cell line (HLEB3) upregulated the expression of Snail and the EMT relevant molecules such as vimentin and α -SMA but downregulated the expression of keratin and E-cadherin. After the stimulation of TGF ß 2, the HLEB3 cells became fibroblast-like in morphology, and the junctions of cell-cell disappeared. TGF ß 2 treatment also enhanced migration ability of HLEB3 cells. TGF ß 2-induced Snail expression and EMT were significantly inhibited by Snail siRNA. By analyzing the response characteristics of HLEB3 in TGF ß 2-induced EMT model with/without Snail-specific siRNA, we concluded that Snail is an element in the EMT of HLEB3 cells induced by TGF ß 2. Snail siRNA targeting can block the induced EMT and therefore has the potential to suppress the development of PCO.