Development of graphitic carbon nitride quantum dots-based oxygen self-sufficient platforms for enhanced corneal crosslinking.

Keratoconus, a disorder characterized by corneal thinning and weakening, results in vision loss. Corneal crosslinking (CXL) can halt the progression of keratoconus. The development of accelerated corneal crosslinking (A-CXL) protocols to shorten the treatment time has been hampered by the rapid depletion of stromal oxygen when higher UVA intensities are used, resulting in a reduced cross-linking effect. It is therefore imperative to develop better methods to increase the oxygen concentration within the corneal stroma during the A-CXL process. Photocatalytic oxygen-generating nanomaterials are promising candidates to solve the hypoxia problem during A-CXL. Biocompatible graphitic carbon nitride (g-C3N4) quantum dots (QDs)-based oxygen self-sufficient platforms including g-C3N4 QDs and riboflavin/g-C3N4 QDs composites (RF@g-C3N4 QDs) have been developed in this study. Both display excellent photocatalytic oxygen generation ability, high reactive oxygen species (ROS) yield, and excellent biosafety. More importantly, the A-CXL effect of the g-C3N4 QDs or RF@g-C3N4 QDs composite on male New Zealand white rabbits is better than that of the riboflavin 5'-phosphate sodium (RF) A-CXL protocol under the same conditions, indicating excellent strengthening of the cornea after A-CXL treatments. These lead us to suggest the potential application of g-C3N4 QDs in A-CXL for corneal ectasias and other corneal diseases.

Multifunctional Hydrogel Eye Drops for Synergistic Treatment of Ocular Inflammatory Disease.

Uveitis is a complex ocular inflammatory disease with a multifactorial etiology that can result in blindness. Although corticosteroid eye drops are the primary treatment for anterior uveitis, their efficacy is limited by low bioavailability, adverse effects, and a narrow focus on inflammation. In this study, the multifunctional hydrogel eye drops (designated as DCFH) were developed by incorporating the anti-inflammatory agent dexamethasone (DSP) and reactive oxygen species (ROS) scavenger cerium-based metal-organic frameworks (Ce-MOFs) into thermosensitive triblock copolymer F127 for the synergistic treatment against uveitis. The resulting F127 eye drops offer a favorable alternative to ophthalmic solution due to its thermosensitivity, thixotropy, light transmittance, improved ocular bioavailability, and unexpected anti-inflammatory efficacy. Notably, the participation of nanoporous Ce-MOFs, functional drug carriers, not only reduces ROS level but also boosts the anti-inflammatory activity of DSP in vitro. Therapeutically, the multifunctional DCFH exhibits superior efficacy in treating endotoxin-induced uveitis by mitigating the ophthalmic inflammatory reaction, suppressing inflammatory cytokines (e.g., TNF-α, IL-6, and IL-17) and downregulating the expression of iNOS and NLPR3. This synergistic treatment provides a valuable and promising approach for the management of uveitis and other ocular inflammatory conditions.

Inter-examiner and intra-examiner reliability of optical coherence tomography angiography in vascular density measurement of retinal and choriocapillaris plexuses in healthy children aged 6-15 years.

Objective: This study aimed to test the inter-examiner and intra-examiner reliability of macular vascular density (VD) measurement of retinal and choriocapillaris plexuses in healthy children using optical coherence tomography angiography (OCTA). Materials and methods: Ninety-two school children were prospectively recruited. Macular OCTA images (6 × 6 mm2) were obtained thrice by two examiners using the RTVue-XR Avanti OCT system. The coefficient of variation (COV), intraclass correlation coefficient (ICC), and Bland-Altman plots were used to evaluate the repeatability and reproducibility. Results: Ninety participants aged 6-15 years were enrolled; two participants were excluded because of low-quality images. In the retina, the reproducibility and repeatability of VD became poorer from superficial to deep retinal capillary plexus (superficial: COV = 4.61-11.11%; intermediate: COV = 7.73-14.15%; deep: COV = 14.60-32.28%). For both reproducibility and repeatability, the ICC ranged from moderate to high (superficial plexus: ICC = 0.570-0.976; intermediate plexus: ICC = 0.720-0.968; deep plexus: ICC = 0.628-0.954). In the choroid, the inter-examiner reproducibility and intra-examiner repeatability of the VD measurement of choriocapillaris were excellent in the macula, fovea, parafovea, and perifovea (COV = 1.00-6.10%; ICC = 0.856-0.950). The parameters of the foveal avascular zone (FAZ) also showed significant reproducibility and repeatability (COV = 0.01-0.21%; ICC = 0.743-0.994). Conclusion: The VD measurements of the choriocapillaris and FAZ parameters using OCTA showed excellent inter-examiner and intra-examiner reliability in school children. The reproducibility and repeatability of the VD of three retinal capillary plexuses depended on the depth of the retinal capillary plexus.

Repeatability and reproducibility of a new fully automatic measurement optical low coherence reflectometry biometer and agreement with swept-source optical coherence tomography-based biometer.

AIMS: To assess the repeatability and reproducibility of the ocular measurements obtained with the Suoer SW-9000 µm Plus, a new fully automatic biometer based on optical low coherence reflectometry (OLCR) biometer, and to compare them to those obtained by a swept-source optical coherence tomography (SS-OCT)-based biometer. METHODS: This prospective study consisted of 115 eyes of 115 healthy subjects. The measurements were taken by the two optical biometers in random order. The measured parameters were axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), anterior chamber depth (ACD), mean keratometry (Km), lens thickness (LT) and corneal diameter (CD). To evaluate the intraobserver repeatability and interobserver reproducibility, the within-subject SD, test-retest variability, coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were adopted. The Bland-Altman plot was drawn to assess the agreement. RESULTS: The repeatability and reproducibility of all parameters for the new device were excellent (ICC>0.960 and CoV<0.71%). The Bland-Altman plots showed high agreement between the OLCR-based and SS-OCT-based devices for AL, CCT, AQD, ACD, Km and LT, with narrow 95% limit of agreements (LoAs) (-0.08 mm to 0.06 mm, -15.91 µm to -1.01 µm, -0.09 mm to 0.09 mm, -0.09 mm to 0.08 mm, -0.47 D to 0.35 D, -0.05 mm to 0.16 mm, respectively) and moderate agreement for CD (95% LoA: -0.67 mm to -0.01 mm). CONCLUSIONS: The new Suoer SW-9000 µm Plus biometer showed excellent repeatability and reproducibility. All the parameters obtained by this biometer were similar to those measured by SS-OCT-based biometer.

Normative Data and Determinants of Macular, Disc, and Peripapillary Vascular Density in Healthy Myopic Children Using Optical Coherence Tomography Angiography.

Objective: To establish a normative database for the vascular density (VD) in macular, disc, and peripapillary regions in healthy myopic children and to evaluate associated ocular features with optical coherence tomography angiography (OCTA). Methods: This was an observational, prospective and cross-sectional study. 776 Chinese healthy myopic children (375 boys and 401 girls) were enrolled, mean (±SD) age 9.84 ± 1.98 (range 6-16) years. En-face angiogram OCTA was performed on 6 mm × 6 mm retinal and 4.5 mm × 4.5 mm disc regions. VD measurements in the macular retina were segmented into the four regions: superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and choriocapillaris (CC). Correlations between macular, disc, and peripapillary VD and possible influencing factors [age, gender, axial length (AL), spherical equivalent refraction (SER), right/left eye, and signal strength index (SSI)] were assessed by Pearson's correlation and multivariate regression analysis. Results: For macular scans, the corrected VD in the ICP region was (48.25 ± 4.24)% for the whole macular retina. The macular ICP VD in most sections was lower than the SCP, DCP, and CC (all P < 0.001). The corrected VD in CC was (72.96 ± 4.42)% for the whole macular retina. The macular CC VD in every section was all higher than the SCP, ICP, and DCP (all P < 0.001). The size of foveal avascular zone (FAZ) and foveal VD 300 (FD-300) was 0.28 mm2± 0.10 mm2 and (58.43 ± 4.17)% respectively. For disc scans, the corrected VD was (58.04 ± 2.73)% for the whole disc area. Both AL and SER were strongly correlated with ICP, DCP, and CC VD in all regions (all P < 0.01). Larger SSI was correlated with a lower VD in the SCP and ICP, and a higher VD in DCP and CC (all P < 0.01). Conclusion: Vascular density values provide large scale normative data on macular, disc, and peripapillary vascular parameters in a large sample of healthy myopic children with OCTA measured in the four different retinal plexuses and regions. The VD in different regions had various influencing factors; mainly a close correlation with AL and SSI.

Bioinspired Synthesis of Ce1-x O2:x%Cu2+ Nanobelts for CO Oxidation and Organic Dye Degradation.

Ce1-x O2:x%Cu2+ nanobelts were bioinspired, designed, and fabricated using commercial filter papers as scaffolds by adding Cu(NO3)2 in the original sol solution of CeO2 nanobelts, which display excellent catalyst properties for CO oxidation and photocatalytic activity for organic dyes. Compared with pure CeO2, CuO belts were synthesized using the same method and the corresponding Ce0.5O2:50%Cu2+ bulk materials were synthesized without filter paper as scaffolds; the synthesized Ce1-x O2:x%Cu2+ nanobelts, especially Ce0.5O2:50%Cu2+ nanobelts, can decrease the reaction temperature of CO to CO2 at 100 °C with the conversion rate of 100%, much lower than the formerly reported kinds of Ce1-x O2:x%Cu2+ catalysts. Meanwhile, the synthesized Ce1-x O2:x%Cu2+ nanobelts also display better photocatalytic activity for organic dyes. All of these results provide useful information for the potential applications of the synthesized Ce1-x O2:x%Cu2+ nanobelts in catalyst fields.

[Study on influence of Three Gorges Project construction on Oncomelania growth condition in Chongqing section].

OBJECTIVE: To understand the effects of the change of climate, vegetation, flooding led by the construction of Three Gorges Project to the growth of Oncomelania snail. METHODS: The spatial analysis function of ArcGIS combined with meteorological data, 1:50 000 and the 1:10 000 digital elevation model were employed to analyzed the climate, flooding and other conditions of the reservoir area, and the field survey was used to investigated the vegetation in this area. RESULTS: The flood time, climate precipitation, sunshine duration, vegetation types and coverage of Three Gorges reservior area can meet the growth needs of Oncomelania snail. However, the characteristic of water impounding winter and disembogueing in summer were not agreed with the life circle of Oncomelania snail. CONCLUSIONS: The environment of flooding in winter and drought in summer in the Three Gorges reservior areas is not suitable for the growth of Oncomelania snail. If the transfusion of snais from other endemic areas can be prevented, the area can be avoid to become snail area.