Metabolomic Profiling of Aqueous Humor from Pathological Myopia Patients with Choroidal Neovascularization.

Choroidal neovascularization (CNV) is a severe complication observed in individuals with pathological myopia (PM). Our hypothesis is that specific metabolic alterations occur during the development of CNV in patients with PM. To investigate this, an untargeted metabolomics analysis was conducted using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) on aqueous humor (AH) samples obtained from meticulously matched PM patients, including those with CNV (n = 11) and without CNV (n = 11). The analysis aimed to identify differentially expressed metabolites between the two groups. Furthermore, the discriminative ability of each metabolite was evaluated using the area under the receiver operating characteristic curve (AUC). Enriched metabolic pathways were determined using the KEGG and MetaboAnalyst databases. Our results revealed the detection of 272 metabolites using GC-MS and 1457 metabolites using LC-MS in AH samples. Among them, 97 metabolites exhibited significant differential expression between the CNV and non-CNV groups. Noteworthy candidates, including D-citramalic acid, biphenyl, and isoleucylproline, demonstrated high AUC values ranging from 0.801 to 1, indicating their potential as disease biomarkers. Additionally, all three metabolites showed a strong association with retinal cystoid edema in CNV patients. Furthermore, the study identified 12 altered metabolic pathways, with five of them related to carbohydrate metabolism, suggesting their involvement in the occurrence of myopic CNV. These findings provide possible disease-specific biomarkers of CNV in PM and suggest the role of disturbed carbohydrate metabolism in its pathogenesis. Larger studies are needed to validate these findings.

Overexpression of Rhodopsin or Its Mutants Leads to Energy Metabolism Dysfunction in 661w Cells.

Purpose: Retinitis pigmentosa (RP) is a heterogeneous group of inherited disorders characterized by photoreceptor degeneration. The rhodopsin gene (RHO) is the most frequent cause of autosomal dominant RP (ADRP), yet it remains unclear how RHO mutations cause heterogeneous phenotypes. Energy failure is a main cause of the secondary cone death during RP progression; however, its role in primary rod death induced by ADRP RHO mutants is unknown. Methods: Three RHO missense mutations were chosen from different clinical classes. Wild-type (WT) RHO and its mutants, P23H (class B1), R135L (class A), and G188R (class B2), were overexpressed in 661w cells, a mouse photoreceptor cell line, and their effects on oxidative phosphorylation (OXPHOS) and aerobic glycolysis were compared separately. Results: Here, we report that energy failure is an early event in the cell death caused by overexpression of WT RHO and its mutants. RHO overexpression leads to OXPHOS deficiency, which might be a result of mitochondrial loss. Nonetheless, only in WT RHO and P23H groups, energy stress triggers AMP-activated protein kinase activation and metabolic reprogramming to increase glycolysis. Metabolic reprogramming impairment in R135L and G188R groups might be the reason why energy failure and cell injury are much more severe in those groups. Conclusions: Our results imply that overexpression of RHO missense mutants have distinct impacts on the two energy metabolic pathways, which might be related to their heterogeneous phenotypes.

MiR-375 mitigates retinal angiogenesis by depressing the JAK2/STAT3 pathway.

Aberrant neovascularization in the retina is an important threat to vision and closely related to several retinal diseases, such as wet form of age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. However, the pathogenesis remains largely unknown. MicroRNAs (miRNAs) have been demonstrated to play critical regulatory roles in angiogenesis. Therefore, we aimed to identify the key miRNAs that regulate retinal neovascularization and elucidate the potential underlying mechanisms. In the present study, we performed RNA sequencing of microRNAs in the retina and found that miR-375 was significantly downregulated in the retina of oxygen-induced retinopathy mice. In retinal microvascular endothelial cells (RMECs), overexpression of miR-375 inhibited cell proliferation and angiogenesis. Conversely, inhibition of miR-375 had the opposite effects. Moreover, our results showed that miR-375 negatively regulated the protein expression of JAK2 by inhibiting its translation. The promoting effects of anti-miR-375 on cell proliferation and angiogenesis were attenuated by an inhibitor of STAT3. These results indicate that miR-375 mitigates cell proliferation and angiogenesis, at least in part, through the JAK2/STAT3 pathway in RMECs, which implies an important underlying mechanism of retinal angiogenesis and provides potential therapeutic targets for retinal microangiopathy.

Proteome Changes Associated with the VEGFR Pathway and Immune System in Diabetic Macular Edema Patients at Different Diabetic Retinopathy Stages.

PURPOSE: Diabetic macular edema (DME) is a major cause of vision loss in all stages of diabetic retinopathy (DR). However, there is limited recognition of aqueous humor (AH) proteome profiles of DME patients at different DR stages. In this study, we aimed to investigate the AH proteome changes between DME patients at the nonproliferative diabetic retinopathy (NPDR) stage and those at the proliferative diabetic retinopathy (PDR) stage. METHODS: A label-free data-independent acquisition based liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis was performed to profile the abundances of AH proteins in 73 eyes from DME patients at different DR stages. Enzyme-linked immunosorbent assay (ELISA) was used to confirm the proteomics results with AH samples from non-diabetic patients and DME patients at the NPDR or PDR stage. RESULTS: LC-MS/MS results showed significantly changed expression of 308 proteins between DME patients in the NPDR and PDR groups. Compared to the NPDR group, the proteins relatively up-regulated in the PDR group are involved in the immune system and/or negative regulation of the cell cycle, while proteins relatively down-regulated in the PDR group are associated with the vascular endothelial growth factor receptor (VEGFR) pathway and/or metabolism. ELISA results further verified the proteomic result of down-regulated expression of the immune-associated protein cystatin C (CST3) in the PDR group compared to that in the NPDR and non-diabetic groups. CONCLUSIONS: In this study, we reported for the first time the decreased abundances of AH proteins associated with the VEGFR pathway and both down- and up-regulated expression of AH proteins associated with the immune system in the PDR group compared to that in the NPDR group. Furthermore, we found negative correlations of immune-associated protein, CST3 concentration in AH with DR severity and central retinal thickness, suggesting CST3 as a promising target independent of the VEGFR pathway in DME-involved DR treatment.

Optical coherence tomography angiography metrics in different stages of diabetic macular edema.

BACKGROUND: To investigate the optical coherence tomography angiography (OCTA) characteristics of diabetic macular edema (DME) at different stages. METHODS: This study was a cross-sectional study. Patients diagnosed with DME were recruited. DME was classified into early, advanced, and severe DME. The vessel density (VD) in the superficial vascular plexus (SVP), deep vascular plexus (DVP) and foveal avascular zone (FAZ) parameters, including FAZ area, FAZ perimeter, acircularity index and foveal VD in a 300-µm-wide region around the FAZ (FD-300), were calculated by the AngioVue software. A multivariate generalized estimating equation was used to evaluate the associations between visual acuity and OCTA metrics. RESULTS: Ninety-two eyes from 74 patients with DME were included in this study. Compared to early (P = 0.006) and advanced DME (P = 0.003), the acircularity index was higher in severe DME. Both whole and parafoveal VD in the DVP decreased in eyes with severe DME compared to early DME (P = 0.018, P = 0.005, respectively) and advanced DME (P = 0.035, P = 0.012, respectively). In the multivariate generalized estimating equation, DME severity, FAZ area and foveal thickness were positively associated with worse visual acuity (P = 0.001, P = 0.007 and P = 0.001, respectively). CONCLUSION: Compared to early and advanced DME, severe DME showed increased irregularity in the FAZ and more extensive vessel damage in the DVP. Greater severity level of DME, larger FAZ area, and increased foveal thickness could be risk factors for poor visual acuity. Trial registration The protocol was published in the Chinese Clinical Trial Registry (ChiCTR2000033082).

Quantitative evaluation of hard exudates in diabetic macular edema by multicolor imaging and their associations with serum lipid levels.

AIMS: To quantify hard exudates (HEs) by multicolor imaging (MCI) and traditional color fundus photography (CFP) in diabetic macular edema (DME), and study their associations with serum lipid levels. METHODS: Observational study. DME patients with HEs were recruited. The HE area and location both by MCI and CFP were measured by ImageJ software. Multivariate regression models were used to analyze the associations of serum lipid levels with the total HE area and HE location. RESULTS: Sixty-two patients (74 eyes) were enrolled to quantify HEs in DME. The total HE area by MCI was larger than that by CFP (P = 0.004), and the distance between the fovea and the nearest HE by MCI was shorter than that by CFP (P = 0.003). The percentage of patients with HEs involving the central macula by MCI was significantly higher than that by CFP (P < 0.001). Furthermore, 62 eyes of 62 patients were included to analyze the associations of HE parameters with serum lipid levels. In both MCI and CFP, the HE areas were positively associated with triglyceride level (P = 0.016, P = 0.022, respectively). HEs involving the central macula were positively associated with triglyceride and low-density cholesterol levels in MCI (P = 0.028, P = 0.046, respectively), while no significant association was found between serum lipid levels and HE location in CFP. CONCLUSIONS: MCI is superior to traditional CFP for the detection of HEs and the analysis of associations between HEs and serum lipid levels in DME.

Corrigendum to "Prevalence of Corneal Astigmatism in Patients before Cataract Surgery in Western China".

[This corrects the article DOI: 10.1155/2020/5063789.].

A Comparison of Subconjunctival Wound Healing between Different Methods of Dissecting Subconjunctival Tissues.

OBJECTIVE: To compare different methods for dissecting subconjunctival tissues by developing subconjunctival wound healing models. METHODS: New Zealand white rabbits were separated into 3 groups based on the method by which the rabbit subconjunctival wound healing model was generated: subconjunctival tissues were dissected episclerally (EPI) or subepithelially (SUB), with a corresponding blank control (CON). All the cases in the experimental groups were surgically prepared with conjunctival flaps, and they were sacrificed on the third postoperative day. At the surgical sites, the protein levels of hypoxia-inducible factor-1 (HIF-1)-α, vascular endothelial growth factor (VEGF)-A, and matrix metalloproteinase (MMP)-2 were detected by Western blot, morphological vascularity was measured by Adobe Photoshop, and subconjunctival fibrosis was assessed by histology. RESULTS: Compared with the CON group, both the EPI and SUB groups showed significantly upregulated protein levels of HIF-1α, VEGF-A, and MMP-2. In addition, the protein levels of HIF-1α, VEGF-A, and MMP-2 were higher in the EPI group than in the SUB group. Morphological vascularity was significantly elevated in the EPI group compared with the SUB and CON groups. Collagen content was markedly increased in the EPI group compared with the SUB and CON groups. CONCLUSIONS: Dissecting subconjunctival tissues subepithelially inhibits subconjunctival fibrosis, which may be instructive in tenonectomy in filtration surgery.

Prevalence of Corneal Astigmatism in Patients before Cataract Surgery in Western China.

PURPOSE: To investigate the demographics and distribution of corneal astigmatism before cataract surgery in patients from western China and to compare and analyze these findings with those of patients in southern China. Setting. People's Hospital of Xinjiang Uygur Autonomous Region. DESIGN: Clinical-based cross-sectional study. METHODS: Patients undergoing cataract surgery in the People's Hospital of Xinjiang Uygur Autonomous Region from February 2012 to August 2019 were recruited. Preoperative keratometric data measured by performing preoperative bilateral partial coherence interferometry (IOLMaster), and patient demographics were recorded and analyzed. RESULTS: This study comprised 12,236 eyes of 7065 patients with a mean age of 64.75 ± 9.66 years, and 52.77% of the patients were female. The mean axial length was 23.14 ± 0.96 mm. Astigmatism ranged from 0 diopters (D) to 6.94 D, with a mean of 1.28 D. Corneal astigmatism was between 0.25 D and 1.25 D in 53.71% of eyes, 1.25 D or higher in 39.06% eyes, and less than 0.25 D in 7.23% of eyes. Astigmatism was with the rule (WTR) in 41.94% of the patients and against the rule (ATR) in 38.80% of patients. The mean flat and steep keratometry measurement was 43.19 ± 1.50 D and 44.24 ± 1.62 D, respectively. After matching, corneal astigmatism in western China was 1.30 ± 1.03 D, and it was significantly higher than that in southern China (0.98 ± 0.67 D, P < 0.001). After matching, the proportion of WTR astigmatism was 40.99% in western China, which was also significantly higher than the proportion (26.46%) in southern China (P < 0.001). CONCLUSION: Corneal astigmatism in patients before cataract surgery in western China was mainly between 0.25 D and 1.25 D. Compared with patients in southern China, patients in western China are younger, have a much higher degree of astigmatism, and have a higher proportion of WTR astigmatism.

Pre-treatment With Ranibizumab Aggravates PDT Injury and Alleviates Inflammatory Response in Choroid-Retinal Endothelial Cells.

Polypoidal choroidal vasculopathy (PCV) is the predominant subtype of exudative age-related macular degeneration in Asians. Although photodynamic therapy (PDT) is widely used for PCV treatment, its long-term beneficial effects are unsatisfactory. Accumulating clinical investigations suggest that combined therapy with anti-vascular endothelial growth factor (anti-VEGF) and PDT is superior to PDT monotherapy. However, the optimal time of anti-VEGF before or after PDT remains controversial, hence it needs to further explore the mechanism underlying combined therapy. PDT causes selective damage to endothelial cells, which determines its angio-occlusive efficiency, yet the impact of anti-VEGF on PDT-induced endothelial injury is unclear. Here, we found that pre- compared to post-treatment with anti-VEGF ranibizumab (rani) significantly aggravates PDT injury in the rhesus macaque choroid-retinal endothelial (RF/6A) cell line. PDT activates apoptosis, necroptosis and NLRP3 inflammasome in RF/6A cells. Pre-treatment with rani promotes PDT-caused apoptosis via triggering caspase 8-mediated extrinsic apoptosis, and caspase 8 might also play a pivotal role in the rani's function of suppressing PDT-induced necroptosis and NLRP3 inflammasome activation. Our results implicate that pre-treatment with rani may enhance the angio-occlusive efficiency of PDT and alleviate endothelial inflammatory response, which gives it a great advantage over post-treatment.

Effect of congenital blepharoptosis on corneal biomechanical properties and changes after ptosis surgery.

OBJECTIVES: We studied the difference in the corneal biomechanical parameters of ptotic and fellow eyes in patients with congenital blepharoptosis. The correlations between corneal biomechanical parameters and demographic or ocular parameters, and the changes after surgery were also researched. METHODS: The corneal biomechanical parameters were measured by Corvis ST tonometry. The central corneal thickness (CCT), axial length (AL) and keratometry measurements were performed with LenStar LS900, and intraocular pressure (IOP) by non-contact applanation tonometry. The parameters were evaluated for the effect of ptosis and the relationship of corneal biomechanical parameters. These examinations were repeated 6 months after blepharoptosis surgery. RESULTS: Twenty-nine patients were enroled. The Corvis ST parameters (Deformation amplitude [DA], A1 times, and A1 velocity), CCT, IOP with NCT, IOP with corrected, differed significantly between ptotic and fellow eyes. CCT was significantly positively correlated with Length A1 and IOP with Corvis, and negatively correlated with IOP corrected by Corvis of the ptotic eyes. The same tendency was found in the fellow eyes. Six months after the ptosis surgery, the differences in corneal biomechanics parameters between ptotic eyes and fellow eyes were not significantly changed. CONCLUSIONS: Congenital blepharoptosis causes significant corneal biomechanical changes measured by Corvis ST. The ptotic eyes had thicker and less deformable corneas. The differences in corneal biomechanics between ptotic eyes and fellow eyes were mostly related to CCT changes. Six months after surgery, these differences in corneal biomechanics did not change significantly.

One-month IOP in mitomycin C-augmented trabeculectomy can predict long-term IOP control in chronic primary angle-closure glaucoma.

PURPOSE: To investigate the predictors of long-term intraocular pressure (IOP) in chronic primary angle-closure glaucoma (CPACG) treated with primary trabeculectomy. METHODS: This study systematically reviewed cases of CPACG treated with primary trabeculectomy. The scleral flaps in all cases were sutured with two stitches in situ and two releasable sutures to ensure watertight under normal IOP conditions during surgery. Mitomycin C was used in all eyes. All patients were followed for 2 years. Digital massage of the bulbus and removal of the releasable suture were performed according to the IOP and shape of the filtering bleb. Demographic data and clinical outcomes were recorded. Factors predicting long-term IOP were identified. RESULTS: A total of 72 patients (88 eyes) with a mean age of 58.51 ± 10.60 years were included in this study. The complete success rate was 89.77% after 2 years. The IOP began to stabilize after 7 days and reached its lowest point at the 1-month follow-up. The preoperative and early postoperative high or low IOP does not affect long-term effects (P > 0.05). There was a positive correlation between postoperative IOP at the 1-month and 2-year follow-ups (r = 0.64, P < 0.001). CONCLUSION: In CPACG patients undergoing primary trabeculectomy, scleral flaps sutured watertightly with two stitches in situ and two releasable sutures under normal IOP conditions can ensure controllable, effective and safe treatment of CPACG. The preoperative and early postoperative high or low IOP does not affect long-term effects. One-month postoperative IOP can be used as a predictor of long-term IOP control.

Investigation of Corneal Astigmatism in Chinese Patients With Primary Angle Closure Disease.

PURPOSE: The purpose of this study was to analyze the demographics and distribution of corneal astigmatism before lens extraction in patients with primary angle closure disease (PACD). METHODS: Preoperative partial coherence interferometry was performed in patients with PACD. The demographic and biometric data, including corneal astigmatism and keratometry (K), were recorded. RESULTS: The study comprised 808 cases (1001 eyes) with a mean age of 67.66±9.07 years, and the mean axial length was 22.55±0.89 mm. The mean corneal astigmatism was 1.08±0.78 diopter (D). Corneal astigmatism was between 0.25 D and 1.25 D in 66.50% of the eyes, 1.25 D or higher in 29.68% of the eyes and <0.25 D in 3.82% of the eyes. The corneal astigmatism of primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) were 1.08±0.77 D, 0.98±0.62 D, and 0.89±0.69 D, respectively. In total, 50.60% of the eyes were classified as astigmatism against the rule (ATR), 28.69% of the eyes were with the rule, and 20.71% of the eyes were oblique. ATR astigmatism increased significantly with age (P<0.001). After matching, corneal astigmatism of PACD was 1.07±0.77 D, although it was statistically significantly higher than that of ARC (0.98±0.66 D, P=0.018), the 2 demonstrated no clinical difference. CONCLUSIONS: The results provide normative data of corneal astigmatism for PACD patients. Corneal astigmatism was mainly distributed between 0.25 D and 1.25 D. The findings largely concur with published results in age-related cataract subjects.