Investigation of subclinical ocular inflammation in the aqueous humor of patients with myopia following bilateral sequential collamer lens implantation.

BACKGROUND: The aqueous humor, a transparent fluid secreted by the ciliary body, supports the lens of the eyeball. In this study, we analyzed the cytokine and chemokine profiles within the aqueous humor of the contralateral eye post-implantation of an implantable collamer lens (ICL) to evaluate potential subclinical inflammation in the second eye subsequent to ICL implantation in the first eye. METHODS: Aqueous humor samples were procured from both eyes of 40 patients (totaling 80 eyes) prior to bilateral ICL insertion. Subsequently, a comprehensive statistical analysis was conducted using the Luminex assay to quantify 30 different cytokines in these samples. RESULTS: Compared to the first eye, the aqueous humor of the second eye demonstrated decreased concentrations of IFN-γ (P = 0.038), IL-13 (P = 0.027), IL-17/IL-17 A (P = 0.012), and IL-4 (P = 0.025). No significant differences were observed in other cytokine levels between the two groups. Patients were then categorized based on the postoperative rise in intraocular pressure (IOP) in the first eye. The group with elevated IOP displayed elevated levels of EGF in the aqueous humor of the first eye (P = 0.013) and higher levels of PDGF-AB/BB in the aqueous humor of the second eye (P = 0.032) compared to the group with normal IOP. Within the elevated IOP group, the levels of EGF (P = 0.013) and IL-17/IL-17 A (P = 0.016) in the aqueous humor were lower in the second eye than in the first eye. In the normal IOP group, cytokine levels did not differ notably between eyes. CONCLUSION: Following sequential ICL implantation, it appears that a protective response may be activated to mitigate subclinical inflammation in the second eye induced by the initial implantation in the first eye. Additionally, the increase in IOP subsequent to surgery in the first eye may correlate with the presence of inflammatory mediators in the aqueous humor.

Myopia prevalence and ocular biometry in children and adolescents at different altitudes: a cross-sectional study in Chongqing and Tibet, China.

OBJECTIVE: To investigate the differences in myopia prevalence and ocular biometry in children and adolescents in Chongqing and Tibet, China. DESIGN: Cross-sectional study. SETTING: The study included children and adolescents aged 6-18 years in Chongqing, a low-altitude region, and in Qamdo, a high-altitude region of Tibet. PARTICIPANTS: A total of 448 participants in Qamdo, Tibet, and 748 participants in Chongqing were enrolled in this study. METHODS: All participants underwent uncorrected visual acuity assessment, non-cycloplegic refraction, axial length (AL) measurement, intraocular pressure (IOP) measurement and corneal tomography. And the participants were grouped according to age (6-8, 9-11, 12-14 and 15-18 years group), and altitude of location (primary school students: group A (average altitude: 325 m), group B (average altitude: 2300 m), group C (average altitude: 3250 and 3170 m) and group D (average altitude: 3870 m)). RESULTS: There was no statistical difference in mean age (12.09±3.15 vs 12.2±3.10, p=0.549) and sex distribution (males, 50.4% vs 47.6%, p=0.339) between the two groups. The Tibet group presented greater spherical equivalent (SE, -0.63 (-2.00, 0.13) vs -0.88 (-2.88, -0.13), p<0.001), shorter AL (23.45±1.02 vs 23.92±1.19, p<0.001), lower prevalence of myopia (39.7% vs 47.6%, p=0.008) and flatter mean curvature power of the cornea (Km, 43.06±1.4 vs 43.26±1.36, p=0.014) than the Chongqing group. Further analysis based on age subgroups revealed that the Tibet group had a lower prevalence of myopia and higher SE in the 12-14, and 15-18 years old groups, shorter AL in the 9-11, 12-14 and 15-18 years old groups, and lower AL to corneal radius of curvature ratio (AL/CR) in all age subgroups compared with the Chongqing group, while Km was similar between the two groups in each age subgroup. Simple linear regression analysis showed that SE decreased with age in both the Tibet and Chongqing groups, with the Tibet group exhibiting a slower rate of decrease (p<0.001). AL and AL/CR increased with age in both the Tibet and Chongqing groups, but the rate of increase was slower in the Tibet group (p<0.001 of both). Multiple linear regression analysis revealed that AL had the greatest effect on SE in both groups, followed by Km. In addition, the children and adolescents in Tibet presented thinner corneal thickness (CCT, p<0.001), smaller white to white distance (WTW, p<0.001), lower IOP (p<0.001) and deeper anterior chamber depth (ACD, p=0.015) than in Chongqing. Comparison of altitude subgroups showed that the prevalence of myopia (p=0.002), SE (p=0.031), AL (p=0.001) and AL/CR (p<0.001) of children at different altitudes was statistically different but the Km (p=0.189) were similar. The highest altitude, Tengchen County, exhibited the lowest prevalence of myopia and greatest SE among children, and the mean AL also decreased with increasing altitude. CONCLUSIONS: Myopia prevalence in Tibet was comparable with that in Chongqing for students aged 6-8 and 9-11 years but was lower and myopia progressed more slowly for students aged 12-14 and 15-18 years than in Chongqing, and AL was the main contributor for this difference, which may be related to higher ultraviolet radiation exposure and lower IOP in children and adolescents at high altitude in Tibet. Differences in AL and AL/CR between Tibet and Chongqing children and adolescents manifested earlier than in SE, underscoring the importance of AL measurement in myopia screening.

Evaluation of childhood developing via optical coherence tomography-angiography in Qamdo, Tibet, China: A prospective cross-sectional, school-based study.

BACKGROUND: Optical coherence tomography angiography (OCTA) is a new and reliable machine used to evaluate retinal structure and macular perfusion in children. The use of OCTA under bad condition such as high altitude, low atmospheric oxygen, and low humidity, in children is rarely. AIM: To quantify the macular micro-vasculature in healthy children of various ages using OCTA in Qamdo. METHODS: Design: Prospective cross-sectional, school-based study. Three hundred and forty-seven normal students from 9 schools in 4 different areas in Qamdo were included. OCTA was performed on a 3 mm × 3 mm area centered on the macular region and macular cube 512 × 128 showed details in macular. Early treatment of diabetic retinopathy study Vessel Flow Density (VD) of the macular central vascular plexus density (CVD), inner vascular plexus density (IVD), full vascular plexus density (FVD), and the size of the foveal avascular zone (FAZ) were measured. All these results corrected by t/s = 3.382 × 0.01306 × (axial length-1.82). The differences were compared among various ages, sexes and living environments. RESULTS: The mean FAZ area in all eyes was 0.27 mm2 ± 0.12 mm2. The mean foveal thickness (MFT) in the macular cube was 227.64 µm ± 23.51 µm. Compared with girls, boys had a lager FAZ (P = 0.0029). Among the different age groups, MFT (P < 0.001) and FVD (P < 0.0001), IVD (P < 0.0001), and CVD (P = 0.0050) increased with age. FAZ areas were not correlated with age (P = 0.8853) or others (MFT, area). CONCLUSION: OCTA can use to evaluate macular perfusion in children. Our data bridge the gap between structural OCT and perfusion density in children in high altitude. Even though these were not a longitudinal study, it may provide us with hints about retina development during puberty and clinical implications of OCTA in children.

Efficacy of cataract surgeries performed during blindness prevention programs in Chongqing, China: a multicenter prospective study.

OBJECTIVE: To determine the efficacy of cataract surgeries in blindness prevention programs in Chongqing. METHODS: During February-December 2019, we prospectively enrolled 487 patients (592 eyes) undergoing cataract surgery during blindness prevention programs in 6 Chongqing district/county hospitals (experimental group) and 481 patients (609 eyes) undergoing cataract surgery in the First Affiliated Hospital of Chongqing Medical University (controls). Uncorrected visual acuity (UCVA), refractive status, best corrected visual acuity (BCVA), slit lamp examination, and visual function/quality of life (VF-QOL) questionnaire scores were evaluated preoperatively, and at 1 and 6 months postoperatively. RESULTS: In the experimental group, UCVA, BCVA, and VF-QOL scores at 1 and 6 months were better than the preoperative values (P < 0.05), but lower than the control-group values (P < 0.05). Rates of good UCVA and BCVA outcomes (≤ 0.5 logMAR) in the experimental group were 76.2% and 87.6%, respectively, at 1 month and 68.9% and 83.1%, respectively, at 6 months. Most eyes in the experimental (82.1%) and control (89.5%) groups had refractive errors within ± 1 D at 1 month. At 6 months, posterior capsule opacification (PCO) was more common in the experimental group (20.9% vs. 15.0%, P < 0.05). At 6 months, the main causes of visual impairment (UCVA > 0.5 logMAR) in the experimental group were uncorrected refractive errors (33.0%), PCO (29.5%), and fundus diseases (33.9%). CONCLUSION: Cataract surgeries in blindness prevention programs in Chongqing significantly improved visual acuity, VF, and QOL, but underperformed compared to surgeries in the tertiary teaching hospital.

Myopia progression and associated factors of refractive status in children and adolescents in Tibet and Chongqing during the COVID-19 pandemic.

Objectives: To investigate myopia progression and associated factors of refractive status among children and adolescents in Tibet and Chongqing in China during the COVID-19 pandemic. Methods: A population-based cross-sectional study was conducted to compare rates of myopia and high myopia, axial length (AL), spherical equivalent (SE), outdoor activity time, digital device use, and frequency of visual examinations for children and adolescents affected by myopia in Chongqing and Tibet in 2021. Results: A total of 2,303 students from Chongqing and 1,687 students from Tibet were examined. The overall prevalence of myopia and high myopia in these two groups were 53.80 and 7.04% vs. 43.86 and 1.30%, respectively in each case. The Chongqing students had a longer AL than the group from Tibet (23.95 vs. 23.40 mm, respectively; p < 0.001). The mean SE of the students with myopic parents in Tibet was lower than that of the students in Chongqing with myopic parents (-2.57 ± 2.38 diopters (D) vs. -2.30 ± 2.34 D, respectively) (p < 0.001). Conversely, the mean SE of the students from urban areas in Chongqing was lower than that of the students in Tibet (-2.26 ± 2.25 D vs. -1.75 ± 1.96 D, respectively; p < 0.001). The Chongqing students exhibited lower SE (-2.44 ± 2.22 D) than their Tibetan counterparts (mean SE: -1.78 ± 1.65 D (p = 0.0001) when spending more than 2.5 h outdoors. For example, 61.35% of the students in Tibet spent more than 2.5 h outdoors daily, compared with 43.04% of the students in Chongqing. Correspondingly, the proportion of students using digital devices in Tibet (64.43%) was lower than that in Chongqing (100%). For the latter, 38.62% of the students in Chongqing spent more than 2.5 h online using digital devices compared to 10.49% of the students in Tibet. Greater monitoring of visual status was observed for the Chongqing students (mean SE: -1.90 ± 1.98 D) compared with students in Tibet (mean SE: -2.68 ± 1.85 D) (p = 0.0448), with the frequency of optimal examinations being every 6 months. Outdoor activity time was identified as a common risk factor for myopia in both of the populations examined, with odds ratios (ORs) of 1.84 (95% CI: 1.79-1.90) in Chongqing and 0.84 (95% CI: 0.73-0.96) in Tibet. Digital screen time was associated with myopia and high myopia in Chongqing, with ORs of 1.15 (95% CI: 1.08-1.22) and 1.06 (95% CI: 0.94-1.77), respectively. Digital screen time was also found to be a risk factor for high myopia in Tibet (OR: 1.21, 95% CI: 0.77-1.61). The type of digital devices used was also associated with myopia and high myopia in Tibet (OR: 1.33, 95% CI: 1.06-1.68 and OR: 1.49, 95% CI: 0.84-2.58, respectively). Finally, examination frequency was found to correlate with high myopia in the Tibet group (OR: 1.79, 95% CI: 0.66-2.71). Conclusion: Based on our data, we observed that the prevalence of refractive errors in children and adolescents was significantly lower in Tibet than in Chongqing. These results are potentially due to prolonged outdoor activity time, and the type and time of use for digital devices that characterize the group of children and adolescents from Tibet. It is recommended that parents and children in Chongqing would benefit from increased awareness regarding myopia progression and its prevention.

Correlation between children and adolescents behavioral habits and the occurrence of myopia in Qamdo / 中国学校卫生

Objective@#To investigate the current status of myopia in children and adolescents in Qamdo, Tibet, and analyze related influencing factors, so as to provide a basis for the prevention and control of adolescents in plateau areas.@*Methods@#A cross sectional study was conducted among 959 children and adolescents randomly selected from one district and two counties in Qamdo (from the fourth grade of elementary school to the second grade of high school) for visual acuity and refraction tests and filled out a vision related behavior questionnaire to analyze the incidence of myopia among adolescents in the region and its associated factors.@*Results@#The myopia rate of adolescents in grades 4-11 was 54.43%, the rate of undercorrection of refractive errors was 85.25%, and the percentage of students wearing eyeglasses was 34.67%,fully vision correction rate was 42.54%. The myopia rate of students in grades 4-6 was 35.14%, 64.71% in grades 7-9, and 73.48% in grades 10-11. The myopia rate increased with grades( χ 2= 101.18 , P <0.01). The myopia rate (70.40%) of urban students (grades 4-9) was higher than that of county level(41.45%), and the myopia rate of students with myopia from either parent (68.24%) was higher than that of students without myopia (51.91%) , the myopia rate of girls (59.96%) was higher than that of boys (48.36%)( χ 2=53.19，13.46，12.98， P <0.01). Use electronic products for more than 2.5 hours per day, electronic devices usage after bedtime, the light low indoor brightness when studying on a sunny day, and only use one of the table lamps or roof lights when studying at night, preference for fried food, poor sleep quality, in the morning the students who still feel tired are at higher risk of myopia( χ 2=10.35, 10.91, 6.87, 4.25, 4.97, 5.71, 12.11, P < 0.05). Multivariate regression analysis showed that the occurrence of myopia was related to region, grade, gender, parental myopia, time spent on electronic products every day in the past 5 months, and sleep quality( P <0.05).@*Conclusion@#The high rate of myopia in children and adolescents in Qamdo may be related to the quality of sleep, the length of time electronic products are used, the eye environment, and the frequency of eating fried foods. Outdoor activities do not show significant differences.

Ocular microbial diversity, community structure, and function at high altitude.

PURPOSE: To investigate the composition and function of ocular surface microbiome in healthy people from different altitudes. METHODS: Thirty-two healthy people living in a high altitude region and 30 sex- and age-matched individuals living in a low altitude region were enrolled. Samples were collected from the lower conjunctival sac of one randomly chosen eye for each participant. 16S rRNA sequencing was conducted to study the bacterial community composition and predict gene function using PICRUSt software. RESULTS: Microbial diversity and richness was significantly decreased in samples from highlanders as calculated by Abundance-based Coverage Estimator (ACE) index, Chao1 index, and observed-species index (all p < 0.01). Principle coordinate analysis (PCoA) suggested significantly distinct clustering of the conjunctival sac bacterial communities between two groups (p = 0.03), especially the dominant genera. The relative abundances of Corynebacterium, Staphylococcus, and Anaerococcus were significantly enriched in highlanders, while those of Pseudomonas and Massilia were significantly decreased as compared with lowlanders (p < 0.01). In the functional annotation analysis, we found that 74 gene pathways, mainly in metabolism, differed in abundance. Pathways related to immune system diseases and infectious diseases were also enriched in highlanders. CONCLUSION: The composition and function of ocular surface microbiome in highlanders were distinct from those of lowlanders and our study may provide a reference catalog of the healthy conjunctival microbiome in highlanders.

Survey on the Progression of Myopia in Children and Adolescents in Chongqing During COVID-19 Pandemic.

Background: The Covid-19 pandemic restricts children and adolescents from doing normal daily activities such as playing outdoors and going to school. The incidence and prevalence of myopia have increased during the COVID-19 pandemic. The aim of this study was to investigate and evaluate the impact of the home confinement during the COVID-19 pandemic on the progression of myopia among children and adolescents in Chongqing, China. Methods: The survey was conducted by using stratified samplings. Samples were randomly selected from the 2019 National Student Physique and Health Survey database, and their visual function and refractive data were compared with those in 2020. Vision-related behavior questionnaire including digital screen exposure was applied to investigate the correlation between eye parameter and eye health-related behavior. Results: A total of 1,733 and 1,728 students were enrolled in 2020 and 2019, respectively. The percentage of myopia students was 55.02% in 2020, which was higher than that in 2019 (44.62%). The mean uncorrected visual acuity (UCVA, LogMAR, 0.35 ± 0.42) in 2020 was higher than that in 2019 (0.27 ± 0.36, P < 0.001). The mean spherical equivalent (SE) refraction (-1.94 ± 2.13 D) in 2020 was lower than that in 2019 (-1.64 ± 5.49 D, P < 0.001). For students who used digital devices for online courses, the mean SE in the television group (-1.10 ± 1.49 D) was better than that in the computer group (-2.03 ± 2.37 D, P = 0.0017) and in the cell phone group (-2.02 ± 2.09 D, P = 0.0028). The average duration of online classes (r = -0.27, P < 0.0001), the number of online classes per day (r = -0.33, P < 0.0001), as well as digital screen exposure time (r = -0.20, P < 0.0001) were negatively correlated with SE, and the average time of outdoor activity (r = 0.20, P < 0.0001) was positively correlated with SE. Conclusions: Increased digital screen exposure contributes to myopic progression in children and adolescents of Chongqing during the COVID-19 pandemic. Suitable digital devices should be provided for online classes and outdoor activity should be advocated to prevent myopic pandemic.

Effect of hypothermic perfusion on phacoemulsification in cataract patients complicated with uveitis: a randomised trial.

BACKGROUND: To evaluate the effectiveness and safety of hypothermic perfusion in the phacoemulsification of cataract caused by uveitis. METHODS: This was a prospective, single-masked, randomised, controlled clinical trial. One hundred and six patients with uveitis-associated cataract underwent phacoemulsification with perfusion fluid temperature at 4 °C (treatment group) or 24 °C (control group). Anterior chamber inflammation grade, corneal endothelial cell count, corneal thickness, macular fovea thickness, and intraocular pressure (IOP) were observed on the 1st day and 7th day after operation. RESULTS: The aqueous flare score was 0.83 ± 0.76 in the 4 °C group, which was lower than that in the 24 °C group (1.51 ± 1.02, p = 0.006) on the first day after operation. The aqueous cells score was lower in the 4 °C group (0.17 ± 0.38) than that in the 24 °C group (0.62 ± 0.94, p = 0.025). The mean corneal thickness of incision in the 4 °C group (907.66 ± 85.37 µm) was thinner than that in the 24 °C group (963.75 ± 103.81 µm, p = 0.005). Corneal endothelial cells density, macular fovea thickness, or percentage of transiently increased IOP showed no difference between the two groups (p > 0.05). There was no significant difference in all the main outcome parameters between the two groups on the 7th day after operation (p > 0.05). CONCLUSIONS: Hypothermic perfusion in the phacoemulsification of uveitis-associated cataract is safe, and it can effectively inhibit anterior chamber inflammation and reduce the incisional corneal edema in the early postoperative stage. TRIAL REGISTRATION: The study was registered with the Chinese Clinical Trial Registry. (http://www.chictr.org.cn/, Registration Number: ChiCTR1800016145).

Effect of hypothermic perfusion on phacoemulsification in eyes with hard nuclear cataract: randomized trial.

PURPOSE: To evaluate the effectiveness and safety of hypothermic perfusion in the phacoemulsification of hard nuclear cataract. SETTING: Tertiary opthalmology center, China. DESIGN: Laboratory study and prospective randomized clinical trial. METHODS: Rabbits and patients with hard nuclear cataract underwent phacoemulsification with perfusion temperatures at 4°C or 24°C. Anterior segment optical coherence tomography (AS-OCT), corneal endothelial cell count (ECC), and cornea sections were observed before the rabbits' operation and 1 day and 7 days postoperatively. AS-OCT, corneal ECC, and anterior chamber (AC) inflammation were observed before the patients' operation and 1 day, 7 days, and 30 days postoperatively. RESULTS: The study comprised 40 rabbits and 80 patients. In the animal models, the mean central corneal thickness (CCT) in the 4°C group (370.4 µm ± 45.5 [SD]) was thinner than in the 24°C group (496.7 ± 121.5 µm) 1 day postoperatively (P < .001). The mean AC inflammation reaction grade in the 4°C group (1.1 ± 0.9) was lower than in the 24°C group (2.2 ± 0.8) (P = .0333). In clinical trials, the mean CCT and incisional corneal thicknesses in the 4°C group (600.7 ± 51.8 µm and 859.2 ± 177.8 µm, respectively) were thinner than in the 24°C group (655.3 ± 85.0 µm and 955.9 ± 196.7 µm, respectively) (P < .001). The endothelial cell density (P = .036) and hexagonality (P = .001) were higher in the 4°C group. The mean AC inflammation reaction grade in the 4°C group (0.6 ± 0.6) was lower than in the 24°C group (1.3 ± 1.0) 1 day postoperatively (P = .004). CONCLUSIONS: Hypothermic perfusion in phacoemulsification of hard nuclear cataract is safe and it can effectively protect corneal endothelium, decrease corneal edema, and reduce AC inflammation in the early postoperative stage.