Swimming exercise reverses transcriptomic changes in aging mouse lens.

BACKGROUND: The benefits of physical activity for the overall well-being of elderly individuals are well-established, the precise mechanisms through which exercise improves pathological changes in the aging lens have yet to be fully understood. METHODS: 3-month-old C57BL/6J mice comprised young sedentary (YS) group, while aging mice (18-month-old) were divided into aging sedentary (AS) group and aging exercising (AE) group. Mice in AE groups underwent sequential stages of swimming exercise. H&E staining was employed to observe alterations in lens morphology. RNA-seq analysis was utilized to examine transcriptomic changes. Furthermore, qPCR and immunohistochemistry were employed for validation of the results. RESULTS: AE group showed alleviation of histopathological aging changes in AS group. By GSEA analysis of the transcriptomic changes, swimming exercise significantly downregulated approximately half of the pathways that underwent alterations upon aging, where notable improvements were 'calcium signaling pathway', 'neuroactive ligand receptor interaction' and 'cell adhesion molecules'. Furthermore, we revealed a total of 92 differentially expressed genes between the YS and AS groups, of which 10 genes were observed to be mitigated by swimming exercise. The result of qPCR was in consistent with the transcriptome data. We conducted immunohistochemical analysis on Ciart, which was of particular interest due to its dual association as a common aging gene and its significant responsiveness to exercise. The Protein-protein Interaction network of Ciart showed the involvement of the regulation of Rorb and Sptbn5 during the process. CONCLUSION: The known benefits of exercise could extend to the aging lens and support further investigation into the specific roles of Ciart-related pathways in aging lens.

The multiple roles of autophagy in uveal melanoma and the microenvironment.

PURPOSE: Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults, and effective clinical treatment strategies are still lacking. Autophagy is a lysosome-dependent degradation system that can encapsulate abnormal proteins, damaged organelles. However, dysfunctional autophagy has multiple types and plays a complex role in tumorigenicity depending on many factors, such as tumor stage, microenvironment, signaling pathway activation, and application of autophagic drugs. METHODS: A systematic review of the literature was conducted to analyze the role of autophagy in UM, as well as describing the development of autophagic drugs and the link between autophagy and the tumor microenvironment. RESULTS: In this review, we summarize current research advances regarding the types of autophagy, the mechanisms of autophagy, the application of autophagy inhibitors or agonists, autophagy and the tumor microenvironment. Finally, we also discuss the relationship between autophagy and UM. CONCLUSION: Understanding the molecular mechanisms of how autophagy differentially affects tumor progression may help to design better therapeutic regimens to prevent and treat UM.

5-Aza-2'-Deoxycytidine Ameliorates Choroidal Neovascularization by Inhibiting the Wnt/ß-Catenin Signaling Pathway.

Purpose: Choroidal neovascularization (CNV) can constitute the final pathology of many ocular diseases and result in severe vision loss. Studies have demonstrated that DNA methylation is critical in retinal development, aging, and disorders. The current work investigated the effects and underlying mechanism of 5-Aza-2'-deoxycytidine (5-aza-dC), a suppressor of DNA methylation, in the pathological progression of CNV. Methods: The DNA methylation profiles of retinal pigment epithelial (RPE)/choroidal complexes in normal and laser-induced CNV mice were assessed by Arraystar Mouse RefSeq Promoter Arrays. The CNV area and blood flow density and intensity were observed by optical coherence tomography angiography, and fluorescence leakage was examined by fundus fluorescein angiography in CNV mice with systemic administration of 5-aza-dC. The effects of 5-aza-dC on the biological functions of bEnd.3 cells were estimated by related assays. Notum gene promoter methylation was measured using bisulfite sequencing PCR. Methyltransferases and Wnt signaling-related genes were detected in animal and cell culture experiments by real-time PCR and immunoblot. Results: Methyltransferases were upregulated, but Notum (a secretion inhibitor of Wnt signaling) was downregulated in the RPE/choroidal complexes of mice with experimental CNV. Intraperitoneal injection of 5-aza-dC inactivated the Wnt pathway and ameliorated the lesion area and the intensity and density of blood flow, as well as the degree of leakage in CNV. In vitro, vascular endothelial growth factor A (VEGFA) stimulation promoted methyltransferases expression and suppressed Notum expression, consequently activating Wnt signaling, whereas exogenous 5-aza-dC reversed VEGFA-induced hyperpermeability, proliferation, migration, and tube formation in bEnd.3 cells via demethylation of Notum promoter. Conclusions: We observed that 5-aza-dC attenuates the growth of CNV by inhibiting the Wnt signaling pathway via promoter demethylation of the Wnt antagonist Notum. These findings provide a theoretical basis for methylation-based treatment with the Notum gene as a potential target for CNV treatment.

The effects of an electronic head-mounted display in vision rehabilitation for patients with tunnel vision.

PURPOSE: To investigate the effect of a new head-mounted electronic visual aid-Acesight on improving visual function and daily activities in patients with tunnel vision. METHODS: 57 patients with tunnel vision participated in this study. The visual field (VF), visual acuity (VA), search ability, time of finding people from the side (TFPS), walking ability, and the subjective feelings of patients with and without Acesight were measured. RESULTS: 15 (36%) patients thought Acesight was "helpful", 16 (28%) thought it was "a little help", and 26 (46%) believed that it was "not helpful." The proportion of people aged < 60 years found Acesight helpful was higher. When wearing Acesight, the average horizontal VF diameter (°) (35.54[8.72]) and vertical VF diameter (°) (26.63[5.38]) were larger than those without visual aids (20.61[9.22], 18.19[6.67]) (P all < 0.001). The average TFPS before and while wearing the Acesight was 1.77s(0.32) and 1.19s(0.29), respectively (t = 14.28, P < 0.001). The average search times, number of collisions, walking speeds when wearing the Acesight were not statistically different from those without visual aids (P all > 0.05). CONCLUSION: More than half of patients with tunnel vision found the Acesight helpful, and a higher proportion of those aged < 60 years old found it helpful. Acesight can expand the horizontal and vertical VF of patients with tunnel vision and can enable patients to detect objects coming from the side earlier. TRIAL REGISTRATION: ChiCTR2000028859; Date of registration: 2020/1/5; URL: http://www.chictr.org.cn/showproj.aspx?proj=47129.

Impact of the preoperative cylinder on astigmatism correction in femtosecond lenticule extraction (FLEX): a prospective observational study.

PURPOSE: To explore the impact of the preoperative manifest cylinder on astigmatism correction via femtosecond lenticule extraction (FLEX), or small incision lenticule extraction (SMILE). METHODS: This was a prospective observational study. Eyes were categorized into mild (n = 88), moderate (n = 46), and severe (n = 53) astigmatism groups, based on the preoperative manifest cylinder. Vector analysis was conducted with the back vertex distance set at 12 mm. The primary outcome was the correction index (CI), with secondary outcomes including the safety, efficacy, predictability, and vectoral alterations related to FLEX. RESULTS: The average target-induced astigmatism was 0.45 ± 0.20 D, 0.95 ± 0.17 D, and 1.99 ± 0.65 D in the three groups (P < 0.001), and the average CI was 1.12± 0.05, 1.01 ± 0.03, and 0.95 ± 0.02 (P = 0.020), with the severe astigmatism group displaying a notably lower CI. The efficacy, safety, predictability, or stability of FLEX did not demonstrate any significant differences among the three groups. The CIs exhibited a significant difference in eyes with with-the-rule (WTR) astigmatism and against-the-rule (ATR) astigmatism from the mild to severe astigmatism group. In eyes with oblique astigmatism, the average CI exceeded one. CONCLUSION: Patients with manifest cylinder exceeding 1.25 D have a heightened risk of under-correction in WTR and ATR astigmatism compared to those with mild astigmatism, and mild over-correction may occur in cases of oblique astigmatism.

Integrative Transcriptome and Proteome Analyses Elucidate the Mechanism of Lens-Induced Myopia in Mice.

Purpose: The purpose of this study was to investigate the underlying molecular mechanism of lens-induced myopia (LIM) through transcriptome and proteome analyses with a modified mouse myopia model. Methods: Four-week-old C57BL/6J mice were treated with a homemade newly designed -25 diopter (D) lens mounting by a 3D printing pen before right eyes for 4 weeks. Refraction (RE) and axial dimensions were measured every 2 weeks. Retinas were analyzed by RNA-sequencing and data-independent acquisition liquid chromatography tandem mass spectrometry. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation, and STRING databases were used to identify significantly affected pathways in transcriptomic and proteomic data sets. Western blot was used to detect the expression of specific proteins. Results: The modified model was accessible and efficient. Mice displayed a significant myopic shift (approximately 8 D) following 4 weeks' of lens treatment. Through transcriptomics and proteomics analysis, we elucidated 175 differently expressed genes (DEGs) and 646 differentially expressed proteins (DEPs) between binoculus. The transcriptomic and proteomic data showed a low correlation. Going over the mRNA protein matches, insulin like growth factor 2 mRNA binding protein 1 (Igf2bp1) was found to be a convincing biomarker of LIM, which was confirmed by Western blot. RNA-seq and proteome profiling confirmed that these two "omics" data sets complemented one another in KEGG pathways annovation. Among these, metabolic and human diseases pathways were considered to be correlated with the LIM forming process. Conclusions: The newly constructed LIM model provides a useful tool for future myopia research. Combining transcriptomic and proteomic analysis may potentially brighten the prospects of novel therapeutic targets for patients with myopia.

The dynamic changes and influencing factors of visual symptoms after small incision lenticule extraction.

BACKGROUND: To investigate the dynamic changes and influencing factors of visual symptoms after small incision lenticule extraction (SMILE). METHODS: This was a prospective observational study. Visual symptoms including glare, haloes, starbursts, hazy vision, fluctuation, blurred vision, double vision and focusing difficulties were evaluated before and 1, 3, 6 months after SMILE using a questionnaire. Generalized linear mixed models were used to assess the effects of preoperative characteristics and objective visual quality parameters on postoperative visual symptoms. RESULTS: 73 patients/146 eyes were enrolled. Preoperatively, the most common symptoms were glare (55% of eyes), haloes (48%), starbursts (44%) and blurred vision (37%). At 1 month postoperatively, the incidence and extent scores of glare, haloes, hazy vision and fluctuation rose significantly. At 3 months, the incidence and extent scores of glare, haloes and hazy vision restored to baseline. And at 6 months, the extent scores of fluctuation returned to baseline. Other symptoms (e.g., starbursts) did not change before and 1, 3, 6 months after SMILE. Preoperative visual symptoms were associated with postoperative symptoms, as patients with a symptom preoperatively had higher postoperative scores for that symptom. Age was related to postoperative extent of double vision (coefficient = 0.12, P = 0.046). There were no significant associations between postoperative visual symptoms and preoperative SE, scotopic pupil size, angle kappa (with intraoperative adjustment), postoperative HOAs or scattering indexes. CONCLUSIONS: The incidence and extent scores of hazy vision, glare, haloes and fluctuation increased at the first month after SMILE, and recovered to baseline at 3 or 6 months. Preoperative visual symptoms were associated with the postoperative symptoms and should be fully considered before SMILE.

MicroRNA-376b-3p Suppresses Choroidal Neovascularization by Regulating Glutaminolysis in Endothelial Cells.

Purpose: Choroidal neovascularization (CNV) is a common pathological change of various ocular diseases that causes serious damage to central vision. Accumulated evidence shows that microRNAs (miRNAs) are closely related with the regulation of endothelial metabolism, which plays crucial roles in angiogenesis. Here, we investigate the molecular mechanism underlying the regulation of endothelial glutamine metabolism by miR-376b-3p in the progression of CNV. Methods: Human retinal microvascular endothelial cells (HRMECs) were transfected with control or miR-376b-3p mimics, and the expression of glutaminase 1 (GLS1), a rate-limiting enzyme in glutaminolysis, was detected by real-time PCR or Western blotting. The biological function and glutamine metabolism of transfected HRMECs were measured by related kits. Luciferase reporter assays were used to validate the CCAAT/enhancer-binding protein beta (CEBPB) was a target of miR-376b-3p. Chromatin immunoprecipitation and RNA immunoprecipitation assays were performed to verify the binding of CEBPB on the promoter region of GLS1. Fundus fluorescein angiography and immunofluorescence detected the effect of miR-376b-3p agomir on rat laser-induced CNV. Results: The expression of miR-376b-3p was decreased, whereas GLS1 expression was increased in the retinal pigment epithelial-choroidal complexes of rats with CNV. HRMECs transfected with miR-376b-3p mimic showed inhibition of CEBPB, resulting in the inactivation of GLS1 transcription and glutaminolysis. Moreover, the miR-376b-3p mimic inhibited proliferation, migration and tube formation but promoted apoptosis in HRMECs, whereas these effects counteracted by α-ketoglutarate supplementation or transfection with CEBPB overexpression plasmid. Finally, the intravitreal administration of the miR-376b-3p agomir restrained CNV formation. Conclusions: Collectively, miR-376b-3p is a suppressor of glutamine metabolism in endothelial cells that could be expected to become a therapeutic target for the treatment of CNV-related diseases.

Comparison of Postoperative Safety, Efficacy, and Visual Quality after SMILE for Myopic Patients with Different Corneal Thicknesses.

PURPOSE: To investigate the safety, efficacy, and visual quality of small incision lenticule extraction (SMILE) in different corneal thickness patients with myopia or myopic astigmatism. METHODS: This prospective cohort study included 191 right eyes of 191 patients. Eyes were divided into three groups according to preoperative central corneal thickness (CCT) (Preoperative central corneal thickness (CCT) was the group indicator.) There were 31 eyes in the thin cornea group (CCT ≤500 um (µm), TC), 94 eyes in the moderate corneal thickness group (CCT ≥501 um (µm) and ≤550 um (µm), MD) and 66 eyes in the thick cornea group (CCT ≥550 um (µm), TK). Comparisons in uncorrected (UDVA) and best-corrected distance visual acuity (BDVA), manifest refractive spherical equivalent (SE), preoperative mesopic/photopic contrast sensitivity (CS), ocular higher-order aberrations (HOAs) at a 6mm analytical pupil diameter, and visual quality questionnaires were made (performed) among the three groups during the postoperative six months. Subgroup analyses were made based on preoperative SE. RESULTS: The safety indices at six months were 1.15 ± 0.18, 1.14 ± 0.17, and 1.18 ± 0.17, respectively (p = 0.374), and the efficacy indices at six months were 1.07 ± 0.25, 1.12 ± 0.22, and 1.11 ± 0.21, respectively (p = 0.599). The postoperative SE was -0.07 ± 0.52D, -0.14 ± 0.38D, and -0.05 ± 0.46D after SMILE in the three groups, respectively (p = 0.376). No significant difference was found in mesopic/photopic CS, HOAs, and visual quality among different corneal thickness groups and SE groups. Postoperative SE and efficacy indices were the lowest in thin cornea eyes with ultra-high myopia (over -9.00 D). CONCLUSIONS: SMILE provides comparable safety, efficacy, and visual quality results in different corneal thickness patients. Those with myopia higher than -9.00 D had less efficacy after surgery, especially in thin cornea patients.

Gut microbiome and plasma metabolome alterations in myopic mice.

Background: Myopia is one of the most common eye diseases leading to blurred distance vision. Inflammatory diseases could trigger or exacerbate myopic changes. Although gut microbiota bacteria are associated with various inflammatory diseases, little is known about its role in myopia. Materials and methods: The mice were randomly divided into control and model groups, with the model group being attached-30D lens onto the eyes for 3 weeks. Then, mouse cecal contents and plasma were collected to analyze their intestinal microbiota and plasma metabolome. Results: We identified that the microbial composition differed considerably between the myopic and non-myopic mice, with the relative abundance of Firmicutes phylum decreased obviously while that of Actinobacteria phylum was increased in myopia. Furthermore, Actinobacteria and Bifidobacterium were positively correlated with axial lengths (ALs) of eyeballs while negatively correlated with refractive diopters. Untargeted metabolomic analysis identified 141 differentially expressed metabolites, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed considerable enrichment mainly in amino acid metabolism pathways. Notably, pathways involved glutamate metabolism including "Glutamine and D-glutamate metabolism" and "Alanine, aspartate and glutamate metabolism" was changed dramatically, which presented as the concentrations of L-Glutamate and L-Glutamine decreased obviously in myopia. Interestingly, microbiome dysbiosis and metabolites alternations in myopia have a disrupting gut barrier feature. We further demonstrated that the gut barrier function was impaired in myopic mice manifesting in decreased expression of Occludin, ZO-1 and increased permeation of FITC-dextran. Discussion: Myopic mice had obviously altered gut microbiome and metabolites profiles compared to non-myopic mice. The dysbiosis and plasma metabolomics shift in myopia had an interrupting gut barrier feature. Our study provides new insights into the possible role of the gut microbiota in myopia and reinforces the potential feasibility of microbiome-based therapies in myopia.

Analysis of macular blood flow changes in thyroid associated ophthalmopathy.

BACKGROUND: To evaluate the changes in macular superficial retinal vessel density and their relation with visual acuity in thyroid-associated ophthalmopathy (TAO) patients with different severity. METHODS: This cross-sectional observational study included 70 TAO patients and 70 healthy controls. Only data from the right eyes were analyzed. TAO patients were divided into 7 subgroups according to the NOSPECS score. Foveal avascular zone (FAZ), vascular density (VD), and perfusion density (PD) of macular 1 mm diameter and 6 mm diameter areas were measured by optical coherence tomography angiography (OCTA). RESULTS: In TAO patients, significant increases were found in macular and foveal vascular densities (FVD) and perfusion densities (FPD) while a significant decrease was found in the FAZ area when compared with the control group (p < 0.05). Spearman correlation analysis and multiple linear regression analysis showed that TAO severity grade was negatively correlated with FVD (ß = -1.150, p = 0.032), FPD (ß = -0.024, p = 0.042), MVD (ß = -0.583, p = 0.020) and MPD (ß = -0.011, p = 0.010). Clinical activity score (CAS) score showed positive correlation with FVD (ß = 0.794, p = 0.035) and FPD(ß = 0.017, p = 0.041). FVD (ß = -0.009, p = 0.033), MVD(ß = -0.034, p < 0.001), FPD(ß = -0.416, p = 0.039) and MPD(ß = -2.428, p < 0.001) all showed negative correlation with best corrected visual acuity (BCVA). CONCLUSIONS: There was an overall increase in superficial macular blood flow in TAO patients compared with healthy controls and the blood flow decreased as TAO got worse. Superficial macular flow density was negatively correlated with BCVA.

Retinal neurodegeneration in a mouse model of green-light-induced myopia.

PURPOSE: To determine the retinal neurodegeneration occurring in mice with green-light-induced myopia. METHODS: Four-week-old mice were raised under white or green light (peak at 510 nm). Refraction and axial length (AL) were measured before and after eight weeks of illumination treatment. TUNEL staining, electron microscopy and the Visual Cliff test were performed to identify the conditions of retinal degeneration. The distinct protein signatures of retina tissues were quantified by mass spectrometry (MS) - based proteomics, and analyzed by Gene Set Enrichment Analysis (GSEA), Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation and STRING database. Western blot was used to detect the expression of the specific protein. RESULTS: Green-light-induced myopia was developed in mice after eight weeks of illumination treatment. Apoptosis and the abnormality in ultrastructure and visual function of mice exposed to green light were found through morphological and behavioral experiment, indicating retinal degeneration. The altered proteome was associated with Human Phenotype Ontology (HPO) annotations sets of 'abnormality of visual evoked potentials' and 'neuronal loss in central nervous system'. KEGG annotation demonstrated the altered pathway of the dopaminergic synapse in the myopic mice. STRING database was utilized with an effort to identify the molecular pathways within, and dysregulation of mitochondrial metabolism was revealed. CONCLUSIONS: Overall, our study revealed molecular differences and pathways underlying retinal degeneration in the mouse model of green-light-induced myopia. These findings might provide insights into further research into myopia prevention and control.

Ophthalmic services in Shanghai 2017: a cataract-centric city-wide government survey.

BACKGROUND: Demand for eye care has increased in recent decades in China due to rapid socioeconomic development and demographic shift. Knowledge of output and productivity of ophthalmic services would allow policymakers to optimize resource allocation, and is therefore essential. This study sought to map the landscape of ophthalmic services available in Shanghai, China. METHODS: In 2018, a government-led survey was conducted of all 86 tertiary/secondary hospitals and five major private hospitals providing eye care in Shanghai in the form of electronic questionnaire, which encompassed ophthalmic services (outpatient and emergency room [ER] visit, inpatient admissions, and surgical volume) and service productivity in terms of annual outpatient and ER visits per doctor, inpatient admissions per bed, and surgical volume per doctor. Comparisons were made among different levels of hospitals with categorical variables tested by Chi-square analysis. RESULTS: The response rate was 85.7%. The Eye and Ear, Nose, and Throat (EENT) Hospital was the largest tertiary specialty hospital, and alone contributed to the highest 21.0% of annual ophthalmic outpatient and ER visits (visits per doctor: 5460), compared with other 26 tertiary hospitals, 46 secondary hospitals and five private hospitals (visits per doctor: 3683, 4651 and 1876). The annual inpatient admission was 20,103, 56,992, 14,090, and 52,047 for the EENT Hospital, all the other tertiary hospitals, secondary hospitals and five private hospitals, respectively. Turnover rates were highest for the EENT Hospital and private hospitals. The average surgical volume at the EENT Hospital was 72,666, exceeding that of private (15,874.8) and other tertiary hospitals (3366.7). The EENT Hospital and private hospitals performed 16,982 (14.2%) and 55,538 (46.6%) of all cataract surgeries. Proportions of both complicated cataractous cases and complicated cataract surgeries at the EENT Hospital was the highest, followed by other tertiary and secondary/private hospitals (P < 0.0001). CONCLUSIONS: In Shanghai, public providers dominate ophthalmic services especially for complicated cases, with almost one fifth of services provided by the EENT Hospital alone, while private sectors, though not large in number, still effectively help meet large proportions of eye care demand. Optimization of hierarchical medical system is warranted to improve the efficiency and standardization of ophthalmic services.

Contribution of M-opsin-based color vision to refractive development in mice.

M-opsin, encoded by opn1mw gene, is involved in green-light perception of mice. The role of M-opsin in emmetropization of mice remains uncertain. To answer the above question, 4-week-old wild-type (WT) mice were exposed to white light or green light (460-600 nm, a peak at 510 nm) for 12 weeks. Refractive development was estimated biweekly. After treatment, retinal function was assessed using electroretinogram (ERG). Dopamine (DA) in the retina was evaluated by high-performance liquid chromatography, M-opsin and S-opsin protein levels by Western blot and ELISA, and mRNA expressions of opn1mw and opn1sw by RT-PCR. Effects of M-opsin were further verified in Opn1mw-/- and WT mice raised in white light for 4 weeks. Refractive development was examined at 4, 6, and 8 weeks after birth. The retinal structure was estimated through hematoxylin and eosin staining (H&E) and transmission electron microscopy (TEM). Retinal wholemounts from WT and Opn1mw-/- mice were co-immunolabeled with M-opsin and S-opsin, their distribution and quantity were then assayed by immunofluorescence staining (IF). Expression of S-opsin protein and opn1sw mRNA were determined by Western blot, ELISA, or RT-PCR. Retinal function and DA content were analyzed by ERG and liquid chromatography tandem-mass spectrometry (LC-MS/MS), respectively. Lastly, visual cliff test was used to evaluate the depth perception of the Opn1mw-/- mice. We found that green light-treated WT mice were more myopic with increased M-opsin expression and decreased DA content than white light-treated WT mice after 12-week illumination. No electrophysiologic abnormalities were recorded in mice exposed to green light compared to those exposed to white light. A more hyperopic shift was further observed in 8-week-old Opn1mw-/- mice in white light with lower DA level and weakened cone function than the WT mice under white light. Neither obvious structural disruption of the retina nor abnormal depth perception was found in Opn1mw-/- mice. Together, these results suggested that the M-opsin-based color vision participated in the refractive development of mice. Overexposure to green light caused myopia, but less perception of the middle-wavelength components in white light promoted hyperopia in mice. Furthermore, possible dopaminergic signaling pathway was suggested in myopia induced by green light.

Short Wavelength (Blue) Light Is Protective for Lens-Induced Myopia in Guinea Pigs Potentially Through a Retinoic Acid-Related Mechanism.

Purpose: To investigate the effect of short-wavelength light (SL) on guinea pigs with lens-induced myopia (LIM) and the possible retinoic acid (RA)-related mechanisms. Methods: Two-week-old guinea pigs (n = 60) with monocular -5D lenses were reared under white light (WL, 580 lux) or SL (440 nm, 500 lux). The left eyes were uncovered as control. Refractive error (RE) and axial length (AL) were measured at baseline, one week, two weeks, and four weeks after intervention. Retinal RA was measured from four guinea pigs after two and four weeks of treatment with HPLC. Two-week-old guinea pigs (n = 52) with monocular -5D lens were fed with either RA or its synthesis inhibitor citral every third day in the morning, and half from each group were reared under WL or SL conditions. RE and AL were recorded at baseline and two and four weeks after intervention. Retinal RA was measured after four weeks of intervention. Results: At the end of treatment, guinea pigs exposed to SL were less myopic than to WL (2.06 ± 1.69D vs. -1.00 ± 1.88D), accompanied with shorter AL (P = 0.01) and less retinal RA (P = 0.02). SL reduced retinal RA even after exogenous RA supplementation (P = 0.02) and decelerated LIM compared to WL (1.66 ± 1.03D vs. -3.53 ± 0.90D). Citral slowed ocular growth, leading to similar RE in W+CI and S+CI groups (3.39 ± 1.65D vs. 5.25 ± 0.80D). Conclusions: Overall, SL reduced LIM in guinea pigs, even in those supplemented with oral RA, accompanied by reduced retinal RA levels. Oral RA accelerated eye elongation, but citral equally decelerated eye elongation under SL and WL with no significant retinal RA reduction.

The assistance of electronic visual aids with perceptual learning for the improvement in visual acuity in visually impaired children.

PURPOSE: To investigate the effect of electronic visual aids (EVA) combined with perceptual learning (PL) for the improvement in visual acuity for moderate to severe visually impaired and blind children. METHODS: Twenty-eight 6- to 14-year-old visually impaired children (19 boys and 9 girls) were divided into two groups: PL under the assistance of EVA (Group A, 14 children) and simple PL without EVA (Group B, 14 children). The content of PL was to search the inversed "E" in the crowding strings and connected with lines, 30 minutes a day for 6 months. EVA can provide 5-10 times magnification on the 4.3-inch screen. Uncorrected distance visual acuity (UCVA), best-corrected visual acuity (BCVA), near visual acuity (NVA) and refractive error were evaluated before and 3 and 6 months after training. RESULTS: Baseline UCVA, BCVA or NVA was comparable between the two groups. Three months after training, UCVA, BCVA and NVA improved significantly in Group A (p < 0.05). At the end of training, UCVA and BCVA continued progressing in Group A compared to 3 months (p = 0.01, 0.02), but visual acuity did not show significant improvement in Group B during the same time, except that UCVA improved at the first follow-up. Refractive error had no significant change post-training in both groups. CONCLUSIONS: Visually impaired children can benefit more from the combination of PL with EVA than simple PL, and the improvement in visual acuity accompanied no significant myopic shift. It may provide a new method of treatment and rehabilitation in visually impaired children.

Changes in Retinal Vasculature and Thickness after Small Incision Lenticule Extraction with Optical Coherence Tomography Angiography.

PURPOSE: To evaluate the changes in retinal vessel density and thickness after small incision lenticule extraction (SMILE) with optical coherence tomography angiography (OCTA) in myopic patients. METHODS: In this prospective study, SMILE surgeries were done in 46 eyes of 24 patients with spherical equivalent (SE) more than -6.0 diopters (D). Retinal vessel density and thickness at the macula and optic nerve were recorded with OCTA before and 1 day, 2 weeks, and 1 month after surgery. Intraocular pressure (IOP), uncorrected distance visual acuity (UDVA), and refraction were taken at the same time. RESULTS: The superficial retinal vessel density and deep foveal retinal vessel density 1 day after surgery were less than those before surgery; however, the changes at any timepoints were not statistically significant (p=0.2736 and p=0.1590, respectively). Both the superficial vessel density and deep vessel density at the parafoveal and perifoveal regions decreased significantly 1 day postoperatively (all p < 0.05) and then returned to the preoperative level at 2 weeks and stabilized thereafter. There were no significant changes in any of the 4 vessel densities in the area of peripapillary before and 1 day, 2 weeks, and 1 month after surgery (p=0.3345). No statistically significant differences between preoperative and postoperative retinal thickness were detected for the area of macula and optic nerve (all p > 0.5). CONCLUSIONS: The vessel density at the parafoveal and perifoveal regions decreased at 1 day after SMILE with no effect on the visual acuity and relieved within 2 weeks. Decreased ocular blood flow in response to the spike in IOP may account for such changes.

Long-Term Natural Course of Pathologic Myopia in Chinese Patients.

PURPOSE: To investigate the natural progression in Chinese patients with pathological myopia (PM) and its associated factors. METHODS: The medical records of 28 patients with PM (worse than -6 diopter), including 31 eyes of 21 children and 12 eyes of 7 adults, were studied. All of the patients underwent a complete ophthalmologic examination at least twice over 3-year period, including the measurement of refractive error (shown as spherical equivalent, SE), axial length (AL), intraocular pressure, visual acuity (uncorrected visual acuity, UCVA, and best-corrected visual acuity, BCVA), and dilated fundus examination. RESULTS: The median AL of adults increased significantly from 29.8 mm to 31.43 mm over 5.4 years follow-up (P=0.0037), accompanied with the median SE progressing significantly from -16.4 D to -18.94 D (P=0.0005). Similarly, the median AL of children increased significantly from 26.13 mm to 27.81 mm over 3.9 years (P=0.0001). However, the improvements of UCVA and BCVA in children were significant (P=0.0304, 0.0001), and they had a negative correlation with age (P=0.0010, 0.0005). Also, UCVA and BCVA in children with bilateral PM were significantly better than those with unilateral PM (P=0.0385, 0.0210). CONCLUSIONS: Fundus degenerations in children with pathological myopia may lead its way since the age of 10 years. Besides, children with bilateral pathological myopia can have parallel development in visual acuity.

Comparative study of wave-front aberration and corneal Asphericity after SMILE and LASEK for myopia: a short and long term study.

BACKGROUND: The study compares the wave-front aberration and corneal asphericity from multiple perspectives after Small Incision Lenticule Extraction and Laser-assisted Subepithelial Keratomileusis for mild to moderate myopia in a short and long time period. METHODS: This prospective and comparative study included 32 eyes in the SMILE group, with a mean spherical equivalent (SE) of - 4.1 ± 0.9D and 32 eyes in the LASEK group, with a mean SE of - 3.7 ± 1.0D. Visual acuity, refractive error, wave-front aberration, corneal Q value and corneal refractive power were analyzed pre-, 3 months and 3 years post-operatively. RESULTS: There was no significant difference in refractive error, wave-front aberration, corneal Q value and corneal refractive power before treatment. Three months postoperative, Q value within 6 mm (SMILE: 0.46 ± 0.27, LASEK: 0.63 ± 0.28, p = 0.02), the relative peripheral corneal power (5-8 mm: p < 0.05), change of higher order aberration (SMILE: 0.10 ± 0.16, LASEK: 0.24 ± 0.20, p = 0.004) and spherical aberration (SA, SMILE: -0.07 ± 0.30, LASEK: -0.41 ± 0.40, p < 0.001) were significantly lower in the SMILE than in LASEK group. The visual acuity, refractive error, coma, peripheral Q value, central corneal power had no significant difference between the two groups. Three years post-operation, the corneal power distribution results and SA were similar to that of 3-month, while the Q value had no significant difference between the two groups. CONCLUSION: In the early stage after SMILE, the HOAs was lower, the corneal refractive power from central to periphery was more uniform than after LASEK; and in the long-term run, SMILE still preceded LASEK in the corneal asphericity and aberration.