Ocular Parameters Research Articles

Bilateral meibomian gland morphological alterations in unilateral herpes simplex keratitis based on artificial intelligence analysis.

To explore whether unilateral herpes simplex keratitis (HSK) can cause morphological changes of bilateral meibomian glands (MGs) based on artificial intelligence (AI) analytical system. In the retrospective study, 29 patients with unilateral HSK and 29 participants matched in terms of age and sex were included as control group. Meibographic images of the upper eyelid using Keratograph 5M and assessed ocular surface parameters including tear meniscus height and tear break-up time. MG density and vagueness values were automatically analyzed and calculated using an AI analytical system. We compared the differences between the affected and the contralateral unaffected eyes in HSK patients, and the normal control eyes. We employed either the paired t-test or the Wilcoxon signed-rank test to compare significant difference between the affected and unaffected eyes in HSK patients or between the HSK group and control group. The MG density was 0.19±0.09 in the HSK-affected eye and 0.18±0.07 in contralateral unaffected eye, which had no significant difference (P=0.616). The MG density between the affected eye with HSK and the normal control group was statistically significant (P=0.028). There was a significant difference in MG density between the contralateral unaffected eye and the normal control group (P=0.012). However, no significant difference in vagueness value was observed between the eye with HSK and the control group or between HSK eye and contralateral eye. The MG density between the HSK-affected eye and the contralateral unaffected eye don't significantly differ, whereas there is a significant decrease in the HSK group compared to that of the normal participants. Unilateral HSV keratitis may suffer from bilateral changes of MG morphology indicating bilateral dry eye. Therefore, the fellow eye of patients with unilateral HSK should be considered a potential case of MG dysfunction, necessitating early treatment for bilateral dry eye in the clinic.

Comparative Study of Adalimumab, Infliximab and Certolizumab Pegol in the Treatment of Cystoid Macular Edema Due to Behçet’s Disease

Background: The leading cause of blindness due to non-infectious uveitis is cystoid macular edema (CME). Behçet’s disease (BD) is one of the most commonly conditions related to CME. Objectives: To compare the effectiveness and safety of adalimumab (ADA), infliximab (IFX) and certolizumab (CZP) in refractory CME due to BD. Methods: Multicenter study of BD-CME patients with no response to glucocorticoids (GCs) and at least one conventional immunosuppressive drug. At baseline, all patients presented CME, defined by OCT > 300 µ. The effectiveness of ADA, IFX and CZP was assessed over a 2-year period from baseline using the following ocular parameters: macular thickness (µm), visual acuity (BCVA), anterior chamber (AC) cells and vitritis. Mixed-effects regression models were applied. Results: a total of 50 patients (75 eyes) were studied (ADA = 25; IFX = 15 and CZP = 10). No significant differences in demographic parameters were found among the three groups. However, individuals in the CZP group had a significantly extended time from diagnosis to treatment onset (72 (36–120) months, p = 0.03) and had received a higher number of biological therapies (1.7 ± 1.1) compared to the ADA and IFX groups. Within the CZP group, ADA and IFX were previously administrated in seven patients. After 2 years of follow-up, a rapid and sustained reduction in macular thickness was noted in all three groups with no significant differences between them. Additionally, enhancements in BCVA, AC cells and vitritis were also observed. No serious adverse events were reported in the CZP group, although one isolated case of bacteremia was documented in the ADA group. ADA, IFX and CZP appear to be effective and safe treatments for refractory CME in BD. CZP seems to remain effective even in patients with an insufficient response to ADA and/or IFX. Conclusions: ADA, IFX and CZP appear to be effective and safe treatments for refractory CME in BD. CZP seems to remain effective even in patients with an insufficient response to ADA and/or IFX.

SMILE and ICL implantation on the ocular surface and meibomian glands in patients with postoperative myopia

BackgroundObjectively compare the changes in ocular surface parameters in myopic patients who have undergone either SMILE or Implantable Collamer Lens (ICL V4c) surgery.MethodsThis prospective cohort study enrolled 32 patients (32 eyes) undergoing SMILE surgery and 35 patients (35 eyes) receiving ICL V4c intraocular lenses. Examinations were performed at preoperative, 1-week, 1-month, and 3-month postoperative time points. The assessments included Schirmer’s I Test (SIt), First Non-Invasive Break-Up Time (First-NIBUT), Average Non-Invasive Break-Up Time (Average-NIBUT), Tear Meniscus Height (TMH), Ocular Surface Disease Index (OSDI) score, conjunctival congestion score, meibomian gland loss score, lipid layer analysis score, lid margin opening detection score, and corneal fluorescein staining (CFS) score.ResultsRepeated measures ANOVA revealed that SIT, TMH, and First-NIBUT initially decreased and then increased. At three months, SIT levels in the SMILE group were significantly lower than those in the ICL group. From the first month onward, TMH levels in the SMILE group remained significantly lower than those in the ICL group (P < 0.05). OSDI scores initially rose and then fell, with the SMILE group consistently showing higher OSDI levels than the ICL group. Conjunctival congestion scores in the SMILE group fluctuated less, while the ICL group exhibited a clear downward trend, with significant differences starting from the first week (P < 0.05). Over time, scores for meibomian gland loss, lipid layer analysis, and lid margin opening detection were all higher in the SMILE group compared to the ICL group.ConclusionsSMILE surgery has a more pronounced and prolonged impact on the ocular surface and meibomian gland function compared to ICL implantation. Objective dry eye parameters in the ICL group recover more quickly than those in the SMILE group one month post-surgery.

A Model to Predict the Risk of Adverse Ocular Outcomes in Pregnant Women

Aims/Background Pregnancy can affect various bodily functions, including metabolism, cardiovascular function, and eyesight. Pathological ocular changes observed during pregnancy are linked to the development of pregnancy-specific conditions, such as preeclampsia/eclampsia and gestational diabetes. This study aims to analyze clinical data disease history and maternal characteristics collected during pregnancy, to determine ocular parameters and develop a risk prediction model for adverse ocular outcomes. Methods We retrospectively analyzed the medical records of 760 pregnant women (1520 eyes) from September 2020 to September 2022 at The Third Affiliated Hospital of Guangzhou Medical University. We identified maternal variables that could influence adverse ocular outcomes, including maternal age, pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), eclampsia, pre-eclampsia, uterine disease, fetal abnormalities, in vitro fertilization with embryo transfer, hypoproteinemia, and major comorbidities during pregnancy. Univariate and multivariate logistic regression analyses were conducted to evaluate the effects of these independent predictors on adverse ocular outcomes. Additionally, receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off probability with for optimal sensitivity and specificity. Results Eclampsia, pre-eclampsia, GDM, a history of chronic hypertension, and hypoproteinemia were identified as independent predictors of adverse ocular outcomes during pregnancy (p &lt; 0.05). Maternal age, PIH, intrauterine growth retardation (IUGR), obesity, and pregnancy with immunoglobulin A nephropathy were predictors of moderate and severe retinal arteriole sclerosis during pregnancy (p &lt; 0.05). Additionally, hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome were predictors of retinal hemorrhage and exudate during pregnancy (p &lt; 0.05). The area under the ROC curve for adverse ocular outcomes were 0.75 and 0.74, respectively. Conclusion Our predictive model effectively forecasts adverse ocular outcomes during pregnancy, incorporating risk factors such as maternal age, eclampsia and pre-eclampsia, GDM, obesity, a history of chronic hypertension, hypoproteinemia, IUGR, pregnancy with immunoglobulin A nephropathy, and HELLP syndrome.

Assessing scleral thickness in patients with POAG and myopia by using OCT.

The aim of the study is to utilize swept-source OCT for imaging the rear sclera near the ONH, calculating the thickness of the SL and lamina, and examining how these measurements correspond to various metrics. Cross-sectional design with a prospective approach. The study included 96 glaucoma patients and 39 control subjects, all with axial lengths greater than 23 mm. Swept-source OCT was used to visualize the subfoveal and ONH regions. Thicknesses of SL and lamina were then calculated from the "B-scan" visuals collected. In order to confirm the consistency of the calculation, "intraclass correlation coefficients" were computed from specific "B-scans". The study compared the thickness of the SL and lamina in subjects with NTG to those with POAG. A "Pearson correlation" was conducted to analyze the connections between the thickness of the SL and lamina with various ocular parameters. Swept-source OCT enabled the measurement of posterior SL thickness in 65.9% and laminar thickness in 89.8% of the subjects. The consistency of measurements taken by different observers and by the same observer varied from moderate to excellent. There was a notable variation among the NTG and POAG sets in terms of subfoveal SL thickness, with measurements of 680.84 ± 170.60 mm and 486.55 ± 125.21 mm, respectively. The connection among subfoveal SL thickness and axial-length was discovered to be negative in subjects with NTG, but this was not observed in subjects with POAG. The variation in connection among the 2 subject groups was statistically important (r [ L0.687, P < 0.002). "Swept-source OCT" identified variations in posterior SL thickness between NTG and POAG eyes. The subfoveal scleral thickness showed a negative association with axial-length, particularly in eyes with normal-tension glaucoma.

Acute effects of high-intensity interval training on microvascular circulation: a case control study in uveal melanoma

Abstract Objectives The aim of this study was to explore the acute effects of high-intensity interval training (HIIT) on the microvascular circulation and vascular tumor microenvironment (TME) in a patient with uveal melanoma (UM). Additionally, the acceptance of the applied diagnostics and the exercise protocol in a clinical ophthalmic-oncology setting were evaluated. Methods This case-control study included a young adult male patient with UM previously treated with radiation and an age-matched healthy control. Participants underwent a baseline assessment of dynamic retinal vessel analysis (DRVA) and cardiopulmonary exercise testing (CPET) to determine endothelial function and intensity for HIIT. Optical coherences tomography angiography (OCTA) was performed before, immediately and 30 min after one session of HIIT. The primary outcome were changes in ocular vessel parameters and whole body oxygen uptake. Results The UM patient exhibited lower arterial dilation and constriction in the affected eye compared to his healthy eye and both eyes of the healthy control. OCTA revealed heterogeneous patterns of vascular response to HIIT in both participants. The tumor eye showed an increase followed by a significant decrease in vessel density post-exercise, while the healthy control exhibited minor increases. Conclusions The findings of this study highlighted the potential of UM combined with OCTA and DRVA as a model for examine exercise-induced vascular effects within the TME. However, a pre-treated UM as well as detailed image analyses and further research with longitudinal, randomized controlled designs are essential to validate these findings and address methodological limitations. Such investigations could refine integrative cancer treatment.

Machine-learning models to predict myopia in children and adolescents.

To explore machine-learning applications in myopia prediction and analyze the influencing factors of myopia. Stratified cluster random sampling was used to select elementary school students in Shenzhen, China for inclusion in this case-control study. Myopia screening, ocular biological parameter measurements, and questionnaires were conducted. Random forest (RF), decision tree (DT), extreme gradient boosting trees (XGBoost), support vector machine (SVM), and logistic regression (LR) algorithms were used to construct five myopia prediction models using R software (version 4.3.0). These myopia prediction models were used to investigate the relationship between ocular biological parameters, environmental factors, behavioral factors, genetic factors, and myopia. This study included 2,947 elementary school students, with a myopia prevalence rate of 47.2%. All five prediction models had an area under the receiver operating characteristic curve (AUC) above 0.75, with prediction accuracy and precision exceeding 0.70. The AUCs in the testing set were 0.846, 0.837, 0.833, and 0.815 for SVM, LR, RF, and XGBoost, respectively, indicating their superior predictive performance to that of DT (0.791). In the RF model, the five most important variables were axial length, age, sex, maternal myopia, and feeding pattern. LR identified axial length was the most significant risk factor for myopia [odds ratio (OR) =8.203], followed by sex (OR = 2.349), maternal myopia (OR = 1.437), Reading and writing posture (OR = 1.270), infant feeding pattern (OR = 1.207), and age (OR = 1.168); corneal radius (OR = 0.034) and anterior chamber depth (OR = 0.516) served as protective factors. Myopia prediction models based on machine learning demonstrated favorable predictive performance and accurately identified myopia risk factors, and may therefore aid in the implementation of myopia prevention and control measures among high-risk individuals.

Automated measurement and correlation analysis of fundus tessellation and optic disc characteristics in myopia

This study aims to quantify fundus tessellated (FT) density and optic disc (OD) morphology using deep learning (DL) techniques and to investigate the correlations between these fundus characteristics and refractive function in young patients with myopia. We constructed two DL-based segmentation models to delineate the FT, OD, peripapillary atrophy (PPA), and macula at a pixel-level resolution. The study sought to identify differences in fundus characteristics between eyes categorized as having high myopia versus mild or moderate myopia. Furthermore, the correlation between fundus measurements and various ocular parameters was statistically analyzed. Correlation analysis indicated that the spherical equivalent and axial length were significantly associated with all fundus measurements (p < 0.001). Additionally, corneal curvature (K1, K2), lens thickness, and foveal thickness exhibited significant correlations with some of the fundus measurements at a 0.01 significance level. Using DL algorithms, it is feasible to automatically quantify FT and OD characteristics in young myopic patients. The study findings suggest that both FT and OD characteristics are highly correlated with the severity of myopia, particularly as it progresses from mild or moderate to high levels. Moreover, a significant relationship exists between most of these fundus characteristics and a spectrum of refractive function parameters.

Relative peripheral refractive errors in Chinese children with myopic anisometropia.

To compare relative peripheral refractive errors (RPREs) in Chinese children with and without myopic anisometropia (MAI) and to explore the relationship between RPRE and myopia. This observational cross-sectional study included 160 children divided into two groups according to the interocular spherical equivalent refraction (SER) difference ≥1.0 D in the MAI group (n=80) and <1.0 D in the non-MAI group (n=80). The MAI group was further divided into two subgroups: ∆SER<2.0 D group and ∆SER≥2.0 D group. Basic ocular biometric parameters of axial length (AL), average keratometry (Ave K), cylinder (CYL), surface regularity index (SRI), and surface asymmetry index (SAI) were recorded. In addition, multispectral refraction topography was performed to measure RPRE, and the parameters were recorded as total refraction difference value (TRDV), refraction difference value (RDV) 0-10, RDV10-20, RDV20-30, RDV30-40, RDV40-53, RDV-superior (RDV-S), RDV-inferior (RDV-I), RDV-temporal (RDV-T) and RDV-nasal (RDV-N). In the non-MAI group, the interocular differences of all parameters of RPRE were not significant. In the MAI group, the interocular differences of TRDV, RDV10-53, RDV-S, RDV-I, RDV-T, and RDV-N were significant. In subgroup analysis, the interocular differences of TRDV, RDV30-53, RDV-I, and RDV-T were significant in ∆SER<2.0 D group and ∆SER≥2.0 D group, but the interocular differences of RDV10-30, RDV-S and RDV-N were only significant in the ∆SER≥2.0 D group. In correlation analysis, ∆TRDV, ∆RDV 10-53, ∆RDV-S, and ∆RDV-N were negatively correlated with ∆SER but positively correlated with ∆AL. The more myopic eyes have larger hyperopic RPRE in Chinese children with MAI in certain retinal range, and partial ∆RPRE is closely associated with ∆SER and ∆AL.

Corneal Curvature of the Saudi Population in Relation to Age, Gender, Refractive Errors, and Central Corneal Thickness.

Corneal curvature (CC) is a crucial ocular optical system parameter, indicating the shape of the cornea expressed in radii. This study aims to investigate the relationship between CC, age, gender, refractive errors, and central corneal thickness (CCT) in Saudi Arabia, a field lacking in research. Data were gathered from Imam Medical Center in Riyadh and Dr. Sulaiman Al Habib Hospital in this randomized, hospital-based, retrospective analysis. Patients sent to the refractive surgery clinic for a laser-assisted in situ keratomileusis (LASIK) evaluation provided a total of 1,005 eyes for the study. Patients with stable refractions in all groups and those between the ages of 17 and 57 with no history of systemic illness, eye operations, or ocular pathology were included in the research, as were all groups with stable refractions. An ultrasound pachymeter was used to assess the CC and CCT. This study showed a mean CC of 42.93+/-1.4 at a mean age of 28.93+/-7.09. We found a significant negative, weak correlation between mean CC and CCT. Gender was not significantly associated with CC in myopic and hyperopic patients, while in patients with astigmatism, females were observed to have a significantly higher mean CC compared to males. A significant difference in the mean CC was observed across different refractive errors, and patients with astigmatism had the highest CC, followed by myopic and hyperopic patients.

Ophthalmic Formulations for the Treatment of Allergic Conjunctivitis and Their Effect on the Ocular Surface: A Review of Safety and Tolerability Assessments in Clinical Trials.

Allergic conjunctivitis (AC) is the most common allergic eye disorder. Antiallergic eyedrops are the first line of pharmacological treatment. However, the application of antiallergic eyedrops can potentially alter tear homeostasis and affect the ocular surface, which may result in iatrogenic diseases such as dye eye disease (DED). Long-term treatment of AC with eyedrops containing preservatives and other components may increase the risk of DED and ocular surface damage. Here, we examined 20 clinical trials published during the past ten years with antihistamine ophthalmic formulations in the treatment of AC, to evaluate the extent of evidence about their safety and tolerability. Remarkably, we find that most trials lack an evaluation of the critical ocular surface parameters, such as tear film break-up time, tear volume, corneal and conjunctival damage, and inflammation, to properly assess the state of the ocular surface state after prolonged treatment. There is a need to increase awareness of the use of specific formulations that do not increase the risk of iatrogenic DED.

Distortion-Corrected Posterior Ocular Shape in Myopic Eyes Assessed by Ultrawide OCT Detects Deformations Associated With Vision-Threatening Changes.

To develop a quantitative tool for assessing the posterior ocular shape using widefield, volumetric optical coherence tomography (OCT) in eyes with myopia. This observational, cross-sectional study included 178 eyes from 113 participants. Participants underwent a standardized eye examination, including ocular biometry and a custom ultrawide OCT. True ocular shape was reconstructed by tracing the beam propagation from the system to the posterior eye. Gaussian curvature quantified the localized ocular shape, which was further categorized into five distinct categories. An ocular shape irregularity (OSI) was calculated using principal component analysis. Linear regression with breakpoints analyzed the relationship between ocular shape parameters and axial length (AL). Increased curvature mean and variance were associated with more severe myopia (P < 0.001). Curvature categories (convex, normal, concave, and highly concave) differed significantly between the groups (all P < 0.001). Their correlations with AL revealed significant breakpoints between 27.1 and 27.2 mm. OSI, as a single metric for quantifying ocular shape distortion, was associated with more severe myopia (P < 0.001), and its correlation with AL revealed a breakpoint at 27.2 mm with a fourfold increase in slope steepness beyond this pivot. Determination of OSI was highly reproducible and could also be obtained with fewer scans. Eyes exceeding 27.2 mm in length exhibit pronounced shape changes. Our framework can be seamlessly integrated into commercial OCTs for ocular shape deformation detection, which could aid in identifying eyes with pathologic myopia.

Influence of Lifestyle Factors on Ocular Surface Parameters in Relation to Age.

To evaluate how Video Display Terminal (VDT) use, Contact Lens (CL) wear, and eyedrop use affect ocular surface parameters in participants with ocular discomfort and how these factors may vary across different age groups. The current cross-sectional study initially involved a total of 252 participants who completed a self-administered survey to collect information about ocular discomfort and lifestyle factors. This online survey was composed of an Ocular Surface Disease Index (OSDI) questionnaire and three extra questions regarding lifestyle factors (VDT use, CL wear, and eyedrop use). Only 185 symptomatic participants, those with OSDI values > 12, were scheduled to undergo a comprehensive ocular examination that included tear film osmolarity, Fluorescein Break-Up Time (FBUT), Maximum Blink Interval (MBI), and corneal staining. Differences in ocular parameters and lifestyle factors across age groups (<40 years, 40-60 years, >60 years) were analyzed, along with their correlations and regression. Significant age group differences were found in OSDI, osmolarity, FBUT, and MBI (One-way ANOVA, all p ≤ 0.029). Correlations were observed between CL wear and osmolarity and MBI (Pearson's correlation, both p ≤ 0.049). Multiple regression confirmed age associations with OSDI, osmolarity, FBUT, and MBI (Multiple linear regression, all p ≤ 0.040) and found links between VDT use and osmolarity and MBI (Multiple linear regression, both p ≤ 0.038) and between eyedrop use and OSDI (Multiple linear regression, p = 0.040). Aging is a primary factor affecting ocular homeostasis, with older adults showing lower FBUT and MBI values and higher osmolarity. Prolonged use of VDTs exacerbates this effect, further contributing to ocular discomfort and destabilized tear film. No associations between CL wear and any of the ocular parameters were found. Eyedrop use shows varied effects on ocular comfort across age groups, emphasizing the need for age-specific ocular care. Overall, these findings confirm that aging and extended VDT use play a significant role in ocular surface discomfort.

Predicting accuracy of spherical equivalent after cataract surgery using the online Zcalc calculator for toric IOLs

Compare Zcalc with other formulas on spherical equivalent prediction errors (PE) and explore the relationship between PE and ocular parameters. Optimize 709 IOL power calculation. 114 eyes with age-related cataract and preoperative regular corneal astigmatism of more than 1.5D were included. They underwent cataract surgery followed by implantation of a toric intraocular lens (Zeiss Torbi 709 M) calculated by Zcalc formula. The prediction errors of spherical equivalent (SE) were analysed 3 months post-surgery. The refractive prediction errors of Zcalc, Barrett Universal II, Kane, and K6 formulas were 0.07 ± 0.63D, − 0.36 ± 0.65D, − 0.41 ± 0.67D, and − 0.31 ± 0.66D, respectively. Statistically significant difference were observed between Zcalc and other formulas. The Zcalc was prone to positive deviation, Barrett Universal II, Kane and K6 were prone to negative deviation. When the axial length is greater than 29.0 mm, the prediction errors of Kane is higher, and prone to negative deviation. Prediction errors of Zcalc are small in all eyes and prone to positive deviation. For more accurate prediction, we recommend Barrett Universal II formula for 709 IOL power calculation.

Effect of the iris-ciliary angle on the prediction of the vault for phakic implantable collamer lens in the manufacturer’s calculator

BackgroundThis study aims to explore the effects of the iris-ciliary angle (ICA) on the accurate prediction of the vault after implantable collamer lens (ICL) using the manufacturer’s online calculation and ordering system (OCOS).MethodsThe participants were categorized into three groups according to the size of ICA as follows: narrow ICA group (< 40°); normal ICA group (40°-60°); wide ICA group (> 60°). We compared the preoperative ocular characteristics and postoperative vault at 3 months among the three groups. Bivariate correlation was used to analyze the correlation between vault and ICA, and multiple linear regression was used to further analyze the correlation between vault and preoperative parameters. Ordered multicategorical logistic regression analyses were used to further illustrate the effect of different ICA groups on postoperative vault distribution.ResultsThis study included 278 eyes of 157 individuals. There were no statistically significant differences in preoperative ocular parameters among the three ICA groups, while the postoperative vault was minimal in the wide ICA group, followed by the normal and then the narrow ICA group (p < 0.001). The correlation between ICA and vault at 3 months postoperatively was significant in both bivariate correlation and multiple linear regression analysis (both P < 0.001). Ordered multicategorical logistic regression analyses showed that the odds of having a higher vault were 2.586 (P = 0.002) and 5.534 (P < 0.001) times in the normal and narrow ICA groups, respectively, compared to the wide ICA group.ConclusionsThe size of the ICA has a significant impact on vault created by the recommended ICL size for OCOS. Therefore, ICA should be considered when selecting ICL size using the OCOS recommended sizes preoperatively.

Correlation between choroidal thickness and the degree of myopia.

Myopia is a frequent visual problem, and the relationship between choroidal thickness (CT) and the degree of myopia has been a hot topic in myopia research. This work aimed to explore the correlation between CT and the degree of myopia, providing a reference for diagnosing and treating myopia. A cross-sectional study was conducted from September 2021 to December 2022, collecting data from 95 myopic patients aged between 18 and 50 years in the outpatient department. All subjects' CT in the macular center (MC), spherical equivalent (SE), and other ocular parameters were measured. Furthermore, the Pearson correlation coefficient (PCC) analyzed relationships between CT and various factors. The choroid was thickest in the MC and gradually became thinner towards the periphery, with the thinnest region located nasally in the healthy group. In the mild, moderate, and severe myopia groups, the choroid was thickest at 1,000 μm temporal to the fovea, becoming thinner towards the periphery, with the thinnest region located nasally. The MC's CT was correlated with a family history of myopia, SE, axial length (AL), and intraocular pressure (IOP). Meanwhile, there was a negative linear relationship between AL and CT in the MC (standard coefficient (SC) of -0.596, P-value of 0.000, tolerance of 0.217, and variance inflation factor (VIF) of 4.467), and a positive linear correlation between SE and CT in the MC (SC of 0.205, P-value of 0.013, tolerance of 0.257, and VIF of 3.792). This work provided clues for further understanding of the pathogenesis of myopic eyes and served as a scientific basis for early screening and treatment of myopia. Additionally, investigating the correlation between myopia and CT can also yield a reference for developing personalized myopia management strategies, which will help slow down myopia's progression and prevent related complications.

Posterior lenticule laser scan influence the ultra-early postoperative visual acuity and quality of SMILE

This is a prospective case-control study investigated the factors influencing ultra-early visual acuity and quality after Small Incision Lenticule Extraction (SMILE) surgery, with a specific focus on the morphology and distribution of “black clefts” observed in posterior lenticule laser scanning images. A total of 174 patients who underwent SMILE surgery were included, and their preoperative ocular clinical parameters, visual quality indicators, and posterior lenticule laser scanning images were analyzed. The morphological features of black clefts were calculated using image processing techniques. Univariate and multivariate logistic analyses were conducted to identify factors impacting ultra-early visual acuity recovery, while correlation analysis was used to explore the association between black cleft morphology and postoperative visual quality. The results showed that although patients experienced significant visual acuity improvement one day after surgery, 26% had poor early recovery. Postoperative visual quality parameters were significantly lower, while the Object Scatter Index (OSI) was higher compared to preoperative values. Patients with poor visual recovery had a higher number of irregular black clefts in their laser scanning images. Logistic regression analysis revealed that intraoperative morphological parameters of black clefts were independent factors influencing early postoperative visual acuity recovery. Additionally, correlation analysis demonstrated a negative correlation between black cleft morphology and postoperative visual quality parameters, and a positive correlation with OSI. In conclusion, the morphology and distribution of black clefts during SMILE surgery significantly affect ultra-early postoperative visual acuity and quality, with increased variability in black cleft area leading to higher OSI, thereby impacting visual quality recovery.

Short-term variability in ocular biometry and the impact of preoperative dry eye.

This study aimed to investigate the short-term variability of ocular biometric measurements and to analyze the factors associated with high variability of biometric values in patients with cataract. This retrospective study included 60 eyes of 60 patients who underwent ocular biometry twice with the IOLMaster 700 (March to November 2023). Ocular surface parameters included tear film break-up time (TBUT), corneal and conjunctival staining scores (CSS/ConSS). Refractive surprise was defined as a mean absolute error exceeding 0.5 diopter (D). Participants included 22 men and 38 women with a mean age of 70.6 ± 8.4 years. The variability of mean keratometric (K) values and astigmatism showed notable variability compared to axial length (mean K: 0.18 ± 0.17D, astigmatism: 0.21 ± 0.26D, axial length: 0.01 ± 0.01mm). A decreased TBUT and increased CSS were significantly associated with high variability (≥ 0.25D) of mean K (p = 0.040/0.008). The high K variability group (≥ 0.25D) revealed a significantly higher incidence of refractive surprise (> 0.5D) compared with the low K variability group (< 0.25D) (45.5%/17.9%, p = 0.037). Preoperative lower TBUT and higher CSS influenced the variability of K values in ocular biometry and may be related with postoperative refractive surprise due to erroneous K values.

Correlation of Central Corneal Thickness and Keratometry Findings With the Severity of Diabetic Retinopathy and Glycosylated Hemoglobin (HbA1c) Levels in Type II Diabetes Mellitus Patients.

Diabetes today is a global health issue, posing a risk to several organ systems. Besides complications like cataracts, diabetic retinopathy (DR), glaucoma and refractive errors, anatomical parameters like central corneal thickness (CCT), which is a crucial indicator of corneal endothelium function and keratometry parameters, have also been noticed to be altered in diabetes. Variations in these parameters may affect the accuracy of applanation tonometry in measuring intraocular pressure. This study aims to investigate variations in CCT and keratometry across different stages of DR, as prior research has yielded inconsistent results. The study also intends to explore the relationship between glycosylated hemoglobin (HbA1C) levels and changes in keratometry and CCT. This observational cross-sectional study was conducted from July 2022 to June 2024. A total of 204 subjects, aged 35-70 years, were included in the study. All participants were evaluated for DR, and those showing fundus findings were graded into five classes based on the Early Treatment Diabetic Retinopathy Study (ETDRS) classification. CCT, keratometry parameters (K1 and K2) and HbA1C levels were measured for all participants. The clinical parameters were correlated across different grades of diabetes mellitus and compared using StatisticalPackage for the Social Sciences (IBM SPSS Statistics for Windows, IBMCorp., Version 23.0, Armonk,NY) software. The patient population consisted of 130 males (63.7%) and 74 females (36.3%). It was found that there was a trend indicating that the presence of DR increased with age, which was statistically significant (p=0.036). However, the differences in the mean duration of diabetes across DR groups were not statistically significant. Findings suggested that individuals with DR generally possess a higher CCT compared to the control group, particularly in the earlier stages of the disease, i.e. noDRand mild non-proliferative diabetic retinopathy (NPDR). However, as the severity of DR increases, the CCT tends to decrease slightly in moderate NPDR, severe NPDR, and proliferative diabetic retinopathy (PDR) stages. The study notes that the variations in CCT across these groups were not statistically significant (p-value of 0.29). The study also found that changes in corneal curvature, as indicated by keratometry values, were more pronounced in the proliferative stage of DR, with a statistically significant increase in k2 values of the left eye (p-value = 0.025). The study concluded that there was no statistically significant relationship between CCT and keratometry values of both eyes with HbA1c levels. While there were some clear patterns, especially concerning age, most variations in ocular parameters were not statistically significant, suggesting that other factors might need an in-depth study in the development of DR and its correlation with ocular parameters. Similarly, while HbA1c has often been stated to be a prognostic factor in diabetes mellitus, significant correlations were neither noted with ocular parameters like CCT and keratometry, nor the stage of retinopathy.

Association between myopia and sleep duration among primary school students in minority regions of Southwest China: a school-based cross-sectional research.

To investigate the relationship between sleep duration and myopia among primary school students in minority regions of Southwest China. The school-based, cross-sectional study was conducted from October 2020 to January 2021. All participants underwent a comprehensive ocular examination and completed a questionnaire on demographic characteristics, ophthalmological history and major environmental factors for myopia. Spherical equivalent (SE) and ocular biometric parameters were measured after cycloplegia, with myopia being defined as SE ≤-0.5 D (Diopter). Multivariate regression models were used to examine the association of sleep duration with myopia, SE and axial length (AL). A total of 857 students from grades 2 to 4 were included in the analysis, of which 63.6% were myopic and 62.0% belonged to ethnic minorities. Boys had a slightly higher prevalence of myopia compared with girls (66.7% vs 60.6%, p=0.06). Myopic students had longer AL, deeper anterior chamber depth and thinner central corneal thickness compared with non-myopic students (all p<0.05). There was no significant association between sleep duration and myopia in both boys and girls (p=0.319 and 0.186, respectively). Moreover, girls with a sleep duration of 8-9 hour/day had higher SE and shorter AL compared with those with less than 8 hour/day of sleep (β=0.41 and -0.32, respectively, all p<0.05). This cross-sectional study did not find a significant association between sleep duration and myopia. However, it suggests that 8-9 hours of sleep per day may have a protective effect on SE progression and AL elongation in girls. Future studies with objectively measured sleep duration are needed to validate the findings.