Refractive Error Research Articles

Causal association of obesity-related anthropometric traits with myopia and the mediating role of educational attainment: a Mendelian randomization study

AIM: To study the causal relationship between obesity-related anthropometric traits and myopia and the mediating role of educational attainment (EA). METHODS: Univariable Mendelian randomization (UVMR) was performed to evaluate the causal association between body mass index (BMI), height, waist-hip ratio (WHR, adjusted for BMI), and mean spherical equivalent (MSE). BMI was divided into fat and fat-free mass and included in multivariable Mendelian randomization (MVMR) to explore the roles of different BMI components in the causal relationship between BMI and MSE. A mediation analysis based on two-step Mendelian randomization (MR) was carried out. Specifically, UVMR was conducted to estimate the causal effect of BMI on EA. The direct effect of EA on MSE was estimated from MVMR. The mediation effect of EA in the BMI-EA-MSE model was calculated by the product of coefficients method. Expression quantitative trait loci (eQTL)-MR, reverse MR, and Linkage Disequilibrium Score Regression (LDSC) were performed to assess the robustness. RESULTS: Genetically predicted higher BMI had a positive total effect on MSE (βIVW=0.26 D, 95%CI=0.14 to 0.37 D, P<0.001), whereas there was no significant association between height, WHR, and MSE. Fat mass was found to play a significant role in the effect of body mass on MSE (βIVW=0.50 D, 95%CI=0.21 to 0.78 D, P=0.001), but there was no significant association between fat-free mass and MSE. The causal effect of BMI on EA was -0.14 (95%CI=-0.16 to -0.11, P<0.001), and the direct effect of EA on MSE was -0.63 D (95%CI=-0.81 to -0.44 D, P<0.001). The mediating effect of EA in the BMI-EA-MSE model was 0.09 D (95%CI=0.06 to 0.12 D), with a mediation proportion of 33% (95%CI=22.1% to 44.6%). No reverse causal associations were detected except for BMI on EA. The results of eQTL-MR and LDSC were consistent with each MR analysis. CONCLUSION: Genetically predicted higher BMI decreases the degree of myopia with a 33% mediation proportion by EA, and fat mass provides a dominant protective role in body mass-myopia. As a supplement to previous observational studies, it provides strong evidence for the relationship between anthropometric traits and refractive errors and offers a theoretical basis for future measures to prevent and control myopia.

Relative peripheral refractive errors in Chinese children with myopic anisometropia

AIM: 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. METHODS: 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). RESULTS: 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. CONCLUSION: 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 of the Saudi Population in Relation to Age, Gender, Refractive Errors, and Central Corneal Thickness

Slowing myopia progression with cylindrical annular refractive elements (CARE) spectacle lenses-Year 1 results from a 2-year prospective, multi-centre trial.

To evaluate the effectiveness of 12 months of spectacle lens wear incorporating cylindrical annular refractive elements (CARE) in slowing myopia progression compared to single vision (SV) spectacle wear. In an ongoing 2-year prospective, double-masked, multi-centre clinical trial, 240 Chinese children aged 6-13 years, spherical equivalent refractive error (SE) -0.75 D to -5.00 D were randomised to one of three groups of 80 participants each to wear: SV spectacle lens (N = 80), CARE spectacles (7 mm central clear zone surrounded by treatment zone incorporating CARE with mean surface power of +4.6 D) and CARE S (9 mm central clear zone surrounded by treatment zone comprising CARE with mean surface power of +3.8 D). Cycloplegic SE and axial length (AL) were measured at 6-month intervals. Compared to baseline, changes in SE and AL were significantly different between the groups at both 6 and 12 months (p < 0.001, linear mixed model). Adjusting for site, group, parental myopia and age, at 12 months, the estimated change in SE and AL with 95% CI with SV was -0.65 D (CI: -0.56 to -0.74 D)/0.32 mm (CI: 0.29-0.36 mm). In comparison, the estimated change in SE/AL at 12 months with CARE was -0.35 D (-0.26 to -0.44 D)/0.19 mm (0.15-0.22 mm) and with CARE S was -0.36 D (-0.27 to -0.46 D)/0.21 mm (0.18-0.25 mm) at 12 months. Progression was slower with CARE and CARE S compared to SV (p < 0.05) but did not differ from each other (p = 0.793 and 0.336 for SE and AL, respectively). In children with myopia, after 12 months of lens wear, both CARE and CARE S spectacle lenses significantly slowed myopia progression compared to SV lenses.

Comparison of clinical outcomes, complications and patient satisfaction following deep anterior lamellar keratoplasty and penetrating keratoplasty.

Keratoplasty is a surgical procedure in which a damaged or diseased cornea is replaced with healthy donor tissue, thereby restoring vision. Recent advancements have led to the replacement of penetrating keratoplasty (PKP) with the more selective deep anterior lamellar keratoplasty (DALK) procedure, especially for treating keratoconus. Although DALK typically has a shorter recovery time, less pain and a lower risk of rejection, PKP is still being performed for more severe corneal diseases. A comparative study of clinical profiles, treatment outcomes and patient-reported satisfaction will provide valuable insights into the cost-effectiveness, impact on quality of life and ability of each procedure to treat different pathologies of the cornea. Here, we aimed to compare the clinical and subjective outcomes of DALK with those of the PKP at a single center in the Kingdom of Saudi Arabia. This retrospective cohort study included eyes that underwent either PKP or DALK from January 2017 to January 2021. The demographic features, indications, best corrected visual acuity (BCVA) and complications of the patients were recorded for both groups, analyzed and compared. A subgroup of eyes with keratoconus was analyzed separately and compared to the larger group. A 6-item survey was conducted via telephone to assess patient satisfaction and expectation, and the results were compared between the two procedures. The chi-square test or Fisher's exact test for categorical variables or the t test or Kruskal‒Wallis test for continuous variables were used as appropriate for all comparisons, and the level of significance was set at α = 0.05. A total of 97 patients were included. PKP and DALK were performed on 63 and 39 eyes, respectively. Patients who underwent DALK were younger (mean ± standard deviation 31 ± 10.82 years versus 43 ± 26.89 years for patients who underwent PKP). The most frequent indication for PKP was keratoconus (35.5%); however, in 97.4% of the eyes undergoing DALK, the indication was keratoconus. In both groups, visual acuity and refractive error improved, but the postoperative corrected distance visual acuity in the DALK group (0.3 log MAR) was noticeably greater than that in the PKP group (0.6 log MAR). Compared with PKP, DALK may carry a lower risk of early graft edema and rejection. Overall, the reported postoperative patient satisfaction was similar for both procedures. The findings highlight the effectiveness of PKP and DALK in improving visual acuity and emphasize the importance of considering patient-reported outcomes in evaluating success. DALK has been demonstrated to be beneficial for protecting the corneal endothelium and lowering the risk of complications and graft rejection.

Exploring the Relationship Between Refractive Errors and Common Chronic Diseases Via Blood Biochemistry Tests: A Large Prospective Cohort Study.

The purpose of this study was to examine the association between refractive errors and common chronic diseases using blood biochemistry tests, and to investigate the associated modifiable risk factors, with the goal of informing and developing effective preventive strategies. A total of 116,245 participants with refractometry at baseline enrolled in the UK Biobank were included in this prospective cohort study. Restricted cubic spline and Cox proportional hazards models were used to detect associations between refractive error, blood biochemistry tests, and common chronic diseases. Interaction effects on the additive scale and effect modification analysis were used to explore excess modifiable risk factors for disease prevention. Spherical equivalent significantly associated with vitamin D, sex hormone binding globulin, apolipoprotein A, blood glucose, and aspartate aminotransferase levels. Subjects with myopia demonstrated a 13% higher risk of type 2 diabetes mellitus (T2DM) incidence compared to those without myopia (hazard ratio [HR] = 1.13, 95% confidence interval [CI] = 1.08-1.19) throughout a median follow-up of 9.12years. Interaction analysis revealed 15% (95% CI = 9%-21%) of this risk was due to myopia-obesity interaction. However, active engagement in physical activity could potentially mitigate this risk (HR = 1.06, 95% CI = 0.93-1.20). Refractive errors were associated with specific blood indicators, particularly noting the association between myopia and higher T2DM incidence in middle-aged and elderly populations. This effect interacts with obesity, and promoting physical activity among myopia individuals provides greater benefits in the prevention of T2DM compared to non-myopic individuals.

Earliest location of glaucomatous retinal nerve fibre layer damage is determined by intact baseline RNFL thickness profile

Background/aimsTo identify whether an intact retinal nerve fibre layer (RNFL) thickness profile could determine the location of the earliest RNFL defect in glaucoma.MethodsRetrospective longitudinal cohort study of patients with initial...

Monochromatic light effects on refractive error, cone cell density and retinoic acid signaling in dorsal and ventral retina in guinea pigs.

Cone cells have been found to influence refractive states. This study investigated whether cone cells and retinal acid (RA) plays a role in refractive states under monochromatic lights. Guinea pigs were exposed to blue (BL), green (GL), or white light (WL), respectively, for 8 weeks. Refractive error (RE), cone cell density, RA, retinoic acid receptor-β (RAR-β), collagen-I expression, and scleral thickness in dorsal and ventral eyes were assessed. Eyes exposed to BL showed a slower shift from hyperopia to emmetropia, particularly in the ventral retina, where higher S-cone density was linked to greater remaining hyperopia. In contrast, GL exposure led to myopic shifts, notably in the dorsal retina, where increased M-cone density was associated with greater reductions in refractive error. BL exposure resulted in similar decreases in RA and retinoic acid receptor-β (RAR-β) expression in both dorsal and ventral regions, along with elevated scleral collagen-I and thicker sclera. In contrast, GL exposure increased RA and RAR-β levels, while reducing scleral collagen-I and thickness. GL-associated changes in RAR-β expression and scleral thinning were more pronounced in the dorsal retina compared to the ventral retina, despite similar RA levels in both regions. These findings suggested that RA may not contribute to the hyperopic shifts with increased S-cone cell density in BL. However, increased RA and RAR-β may be correlated with ocular growth in guinea pigs exposed to GL, it may underlie myopic shifts with increased M-cone cell density.

Estimating the True Effect of Lifestyle Risk Factors for Myopia: A Longitudinal Study of UK Children.

Lifestyle risk factors are implicated in driving the current surge in myopia prevalence yet, paradoxically, known risk factors explain little of the variation in refractive error in the population. Here, we applied "instrumental variable" (IV) methods designed to avoid reverse causation and decrease confounding bias, to gauge lifestyle risk factor effect sizes. Three myopia risk factors (time outdoors, time reading, and sleep duration) were assessed in participants of the Avon Longitudinal Study of Parents and Children: a cross-sectional sample of 2302 children aged 15years old and a longitudinal sample of 3086 children followed from age 7 to 15years. Seven IVs were considered jointly: dog ownership, cat ownership, bedtime variability, birth order, and polygenic scores quantifying genetic predisposition to spend additional time outdoors, years in fulltime education, and time asleep overnight. Risk factor effect sizes were 4-fold to 9-fold higher in the IV analyses compared with conventional regression analyses. In IV analyses, one extra hour spent outdoors every day during childhood was associated with a shift toward hyperopia of +0.53 to +0.94 diopters (D), whereas 1 extra hour spent reading every day was associated with a shift toward myopia of -0.44 to -0.88 D. There was inconsistent evidence that sleep duration influenced refractive error. Myopia risk factor effects were underestimated up to 9-fold in conventional analyses in this sample, compared with IV analyses. We speculate that the effects of lifestyle risk factors for myopia have been underestimated in past studies.

POSSIBILITIES OF AUTOREFKERATOMETRY

In modern ophthalmology, autorefkeratometry has long become a routine diagnostic study, without which it is impossible to imagine any examination. Computerized autorefkeratometers allow you to obtain a huge amount of information about the condition of the patient’s eye in a short time. At the same time, the information obtained is not always subjected to in-depth analysis.Refractometry data should be compared with keratometry data, compared with the indicators of the paired eye, and evaluate, if possible, the dynamics of changes and their tendency. Comparison of the obtained parameters with the average statistical indicators and the age norm make it possible to establish the presence of pathology that does not belong to the field of refractive errors. Thus, the occurrence of anisometropia with similar keratometry parameters suggests opacity of the lens or vitreous pathology. Direct astigmatism is typical for young people, and oblique or reverse astigmatism is typical for patients 65+. A shift in the irido-lens diaphragm is always accompanied by a change in refraction and its instability. Keratectasias are characterized by high variability in refraction and keratometry data, while sometimes maintaining high visual acuity that does not correspond to changes in optical power. Diopter syndrome is manifested by refractive transformations in accordance with changes in the anterior-posterior axis of the eye due to retinal edema. Dry eye syndrome can be manifested by noticeable refractive instability and errors in determining keratometric parameters.High-quality performance of autorefkeratometry, taking into account the nuances, and an in-depth analysis of the data obtained are necessary for making a diagnosis and assessing the dynamics of treatment of ocular pathology.

Impact of proxymetacaine on the dynamics of cyclopentolate in White 6- to 7-year-olds.

This study compared the efficacy of cyclopentolate hydrochloride at 10-, 20- and 30-min post-instillation in White 6- to 7-year-olds, with and without prior instillation of proxymetacaine hydrochloride. The primary aim was to determine if accurate autorefraction values can be obtained sooner than the current standard of 30-min post-cycloplegia. The secondary aim was to investigate whether proxymetacaine hydrochloride enhances the efficiency of cyclopentolate. Participants were 112 White 6- to 7-year-olds from the Child Eye Health Study. The right eye received 0.5% proxymetacaine hydrochloride and 1.0% cyclopentolate hydrochloride, and the left eye received only 1.0% cyclopentolate hydrochloride. Non-cycloplegic and cycloplegic refractive error (at 0, 10, 20 and 30 min) was measured using a binocular, open-field autorefractometer. Data were analysed through paired t-tests, concordance analysis, linear regression, equivalence testing and Bland-Altman analysis, using the 95% limits of agreement. Mean spherical equivalent refraction (SER) (SD) in the right eye at 0-, 10-, 20- and 30-min post-instillation was 0.62 (1.45) D, 1.52 (1.80) D, 1.64 (1.81) D and 1.72 (1.80) D, respectively. Mean left eye SER (SD) were 0.68 (1.24) D, 1.42 (1.66) D, 1.56 (1.66) D and 1.68 (1.72) D, respectively. Bland-Altman analysis showed a high level of agreement, and equivalence testing confirmed that there was no clinically significant difference in SER at 20 and 30 min in both eyes (within ±0.50 D), with mean differences of 0.08 (0.23) D in the right eye and 0.13 (0.30) D in the left eye (p = 0.21). However, SER at 10 and 30 min were equivalent in the right eye only. Accurate autorefraction values can be obtained 20-min post-instillation of 1.0% cyclopentolate in white children aged 6-7 years, potentially reducing clinical testing times. Proxymetacaine pre-instillation allows for reliable measurements as early as 10-min post-instillation of cyclopentolate. Further research is needed to validate these findings in non-White populations and to determine the safe discharge time post-proxymetacaine instillation.

Associations of prenatal arsenic exposure with myopia in primary school children: modifying effects of vitamin D levels.

The increasing role of environmental pollutants and nutrients in the development of myopia. Further longitudinal evidence is needed to elucidate the effects of early-life environmental pollutants on myopia and nutrients to protect against pollutant-induced myopia. We used mother-child dyads from the Ma'anshan Birth Cohort (n = 2028) to explore the modifying effects of maternal vitamin D status of prenatal and childhood arsenic exposure with refractive parameters and myopia. We measured serum or plasma arsenic concentrations during three trimesters, in cord blood, in childhood (5-year-old), and performed cycloplegic refraction in children aged 7 to 9 years (n = 1616). Primary outcomes were myopia and refractive parameters including axial length (AL), corneal radius of curvature, and spherical equivalent refraction error. Linear regression, logistic regression, and multiple informant models were performed for the association of prenatal and childhood arsenic exposure with vision health. Sex- and vitamin D status stratification analyses were also conducted. Cord serum arsenic was positively associated with AL (β = 0.15, 95%CI: 0.01, 0.29) and the risk of developing myopia (OR = 1.72, 95%CI: 1.07, 2.75). Among boys, a 1 ng/L increase in cord serum log10-transformed arsenic resulted in larger AL and a higher risk of myopia. In the vitamin D deficient group (<20 ng/mL), cord serum arsenic showed positive associations with AL (0.26 [0.06, 0.46]) and the risk of myopia (1.99 [1.01, 3.90]). Late pregnancy arsenic exposure likely affects offspring development of myopia, especially in boys. Maternal sufficient vitamin D may confer protective effects against the development of myopia.

Curvature of Posterior Pole in Eyes with Retinitis Pigmentosa

Background/Objectives: This study aimed to determine whether there is a significant change in eyeball curvature in eyes with retinitis pigmentosa (RP). Methods: The medical records of 35 eyes of 18 patients with RP and age- and axial-length-matched controls were reviewed. The curvature of the posterior pole was determined by approximating a second-order polynomial equation based on the optical coherence tomography (OCT) images. Associations among eyeball curvature, refractive error, and axial length were investigated. Results: The average age of patients with RP was 65.1 ± 13.8 years, and the average axial length of the eye was 23.90 mm. The curvature of the posterior eyeball was steeper in eyes with RP (p = 0.020), and the choroid was thinner in eyes with RP (p &lt; 0.01). The curvature of eyes with RP significantly correlated with refractive error (p = 0.006, r = −0.46) and axial length (p = 0.004, r = −0.48). Conclusions: The significant correlation between eyeball curvature and axial length suggests that myopia affects eyeball shape even in eyes with RP. However, the curvature remained steep in the eyes with RP after matching for age and axial length. A thinner choroid was observed in eyes with RP and may play a role in the steeper posterior eyeball.

Refractive outcomes for secondary sutureless posterior chamber lens implantation: sutureless scleral fixating lens Carlevale® versus retropupillary iris-claw lens Artisan®.

To compare refractive outcomes of the foldable intraocular lens sutureless scleral fixated sutureless (Carlevale® FIL-SSF) with the iris-claw lens (Artisan®). This retrospective study included consecutive patients who underwent a FIL-SSF implantation or an iris-claw implantation between January 2020 and November 2022 in the ophthalmology departments of Hospices Civils de Lyon (France). A total of 271 eyes from 265 patients were included: 96 eyes in the FIL-SSF group and 175 eyes in the iris-claw group. At 6months, the mean (SD) surgically induced astigmatism (SIA) was significantly lower in the FIL-SSF group with 0.3 (1.8) diopters against 0.8 (2.1) diopters in the iris-claw group (p = 0.01). The mean (SD) refractive error was also lower for the FIL-SSF group with 0.1 (1.2) diopters versus 0.5 (1.6) diopters in the iris-claw group (p < 0.001). The mean best corrected visual acuity at 6months was not significantly different between FIL-SSF and iris-claw lens with 0.47 (0.58) logMAR and 0.39 (0.55) logMAR, respectively (p = 0.12). However, the mean (SD) operative time was longer for FIL-SSF implantation in comparison to iris-claw implantation (59.8 (21.1) minutes versus 41.9 (24.4) minutes, respectively (p < 0.001)). The rate of postoperative complications was similar between the two techniques. This study shows that FIL-SSF achieves better refractive results than iris-claw lens, with a similar rate of postoperative complications. As a relatively new implantation technique, there is a learning curve required to reduce operating time. What is known? Multiple surgical options for correcting aphakia in the absence of capsular support can be used. Currently, foldable intraocular lens sutureless scleral fixated sutureless (FIL-SSF, Carlevale®) and iris-claw (Artisan®) implants are the two preferred options, but there is no consensus on the best technique to adopt. What is new? We showed that FIL-SSF has a significantly lower surgically induced astigmatism compared to the iris-claw implant. Similar rate of postoperative complications was found between these two techniques. Future studies with a longer follow-up period are needed to ascertain its tolerance.

Comparison of refractive outcomes in patients following scleral fixated intraocular lens implantation with Yamane and Z-suture techniques.

To compare visual and refractive outcomes in aphakic patients who underwent scleral fixated intraocular lens (SF-IOL) implantation with Yamane and Z-suture techniques. Retrospective study. Patients who underwent SF-IOL implantation with Yamane and Z-suture techniques due to aphakia between 2021 and 2023 were analyzed. Preoperative and postoperative 6. month best corrected visual acuity (BCVA-LogMAR), preoperative and postoperative spherical error, cylindrical error and postoperative mean absolute error (MAE), corneal endothelial and topographic parameters, 3 mm-6 mm pupil diameter corneal higher-order aberrations (HOAs) were evaluated. Seventy-seven eyes of 77 patients who underwent SF-IOL implantation with Yamane and Z-suture techniques were included in the study. Yamane technique was performed in 38 (49.4%) and Z-suture technique in 39 (50.6%) patients. Postoperative BCVA was 0.44 ± 0.40 in Yamane technique and 0.47 ± 0.44 in Z-suture technique (p = 0.73). Postoperative MAE was 0.84 ± 0.70 D in Yamane technique, 1.02 ± 0.88D in Z-suture technique (p = 0.33). Postoperative CCT-preoperative CCT (ΔCCT) was 3.76 ± 27.62 µm in Yamane technique and 3.02 ± 15.58 µm in Z-suture technique (p = 0.88). A significant difference was found between Yamane and Z-suture techniques only in the ΔTrefoil value at 6-mm pupil diameter in corneal HOAs. ΔTrefoil was significantly lower in Yamane technique (p = 0.04). Except ΔTrefoil value at 6-mm pupil diameter, although no significant difference was found, corneal endothelial and topographic parameters were less affected in Yamane technique compared to Z-suture technique.

Comparison of two formulas for calculating intraocular lens in patients with angle-closure glaucoma.

This study compares the accuracy of SRK/T and Barrett Universal II intraocular lens (IOL) measurement formulas for cataract phacoemulsification combined with intraocular lens implantation in angle-closure glaucoma (ACG) patients. Prospective serial case studies were conducted. A total of 146 patients (146 eyes) with ACG complicated with cataract who underwent cataract surgery with atrial angle closure ≤180° were observed. All the patients were divided into 2 groups according to different intraocular lens calculation formula, with 73 cases in each group (73 eyes). SRK/T intraocular lens calculation formula was used in group A, and Barrett intraocular lens calculation formula was used in group B. The visual acuity, the best corrected visual acuity, intraocular pressure and central anterior chamber depth were significantly improved in 146 eyes 3 months after operation, and the differences were statistically significant. There was statistically significant difference in postoperative spherical equivalent (SE) between the 2 groups (t = 2.147, P = .033), and there was statistically significant difference in preoperative expected refraction between group A and postoperative SE (t = 4.221, P < .001). There was no significant difference between preoperative expected diopter and postoperative SE in group B (t = 1.857, P = .065). The difference in absolute predicted error between the 2 groups was statistically significant (t = 4.929, P < .001). Axis length was negatively correlated with SRK/T formula and Barrett Universal II formula absolute refractive error value (ME) (group A: r = -0.740, P < .001; group B: r = -0.532, P < .001), there was A significant negative correlation between absolute refractive error value and anterior chamber depth in both groups (group A: r = -0.382, P = .001; group B: r = -0.358, P = .002). The cataract phacoemulsification combined with intraocular lens implantation is safe and effective for ACG patients with cataract. For such patients, the Barrett Universal II intraocular lens measurement formula may be more accurate after surgery.

Recurrence of Retinopathy of Prematurity Following Anti-vascular Endothelial Growth Factor (Anti-VEGF) Therapy: A Systematic Review and Meta-Analysis.

Retinopathy of prematurity (ROP) is a neovascular disorder which affects premature infantsand can lead to childhood blindness. Treatment includes laser photocoagulation and intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections, both effective options. However, laser photocoagulation can lead to refractive errors, while anti-VEGF therapy can result in disease recurrence. Our systematic review aimed to evaluate the recurrence rates of ROP following treatment with anti-VEGF agents compared to other anti-VEGF agents and laser photocoagulation. We also aimed to measure the retreatment intervals and assess successful retreatment rates to identify the most effectivetreatment modality. Our review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and included both randomized controlled trials (RCTs) and non-randomized comparative studies (NCS). A thorough search of MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases was performed. Studies were assessed using the Cochrane Risk of Bias (RoB2) tool and the Newcastle-Ottawa Scale (NOS). Random-effects and fixed-effects models were used to measure pooled estimates. The outcomes were reported as risk ratios (RR) and standardized mean differences (SMD). A total of 21 studies (six RCTs and 15NCS) with 6,152 eyes were included. Overall, anti-VEGF agents showed a higher risk of recurrence compared to laser photocoagulation (RR=2.14, 95% CI: 1.06-4.33, p=0.03). Conbercept demonstrated a significantly lower risk of recurrence than laser photocoagulation and ranibizumab (RR=0.47, 95% CI: 0.39-0.58, p<0.00001), while aflibercept showed a higher recurrence risk compared to bevacizumab (RR=12.61, 95% CI: 6.43-24.73, p<0.00001). Bevacizumab was associated with a longer retreatment interval than laser photocoagulation (SMD=0.89, 95% CI: 0.61-1.17, p<0.00001). No significant differences in retreatment success rates between bevacizumab and laser photocoagulation were observed. Anti-VEGF therapy is effective in the treatment of ROP; however, it is associated with a higher risk of recurrence compared to laser photocoagulation. Conbercept shows greater efficacy in reducing recurrence risk and prolonging the retreatment interval compared to ranibizumab. Aflibercept demonstrated inconsistent outcomes. No significant difference in recurrence rates was observed between bevacizumab and ranibizumab. Recurrences occurred significantly later when anti-VEGF therapy was used compared to laser photocoagulation. Successful retreatment rates between bevacizumab and laser photocoagulation were similar.

Interventions to prevent visual fatigue during robotic surgery.

The robotic surgeon is at risk of visual fatigue from prolonged viewing of the video display resulting in digital eye strain and use of the three-dimensional binoculars resulting in accommodative stress. Symptoms of digital eye strain include blurred vision, dry eyes, eyestrain, neck and back ache, diplopia, light sensitivity, and headaches. Vergence or accommodation-related symptoms include blurred near or distance vision, difficulty refocusing, and diplopia. Beneficial ergonomic interventions to manage digital eye strain during robotic surgery include appropriate lighting, improved neck positioning, optimal screen positioning, improved image parameters, screen breaks, optimising environmental factors, and eye exercises. Correction of refractive error, use of lubricating eye drops, and blink efficiency training to induce motor memory have been shown to be effective in reducing visual fatigue. Vergence-accommodation mismatch can be reduced with slower movement of the camera, screen breaks, and correction of refractive error. Robotic surgeons should adopt these simple and non-invasive interventions to minimise visual fatigue.

Refractive Profiles in Children Receiving School-Based Eye Exams Following Vision Screening from a Large School-Based Vision Program in 2016 to 2022

ABSTRACT Purpose To describe refractive error findings and associated factors in students who received school-based eye exams following vision screenings. Methods Cross-sectional study of pre-kindergarten through 12th grade students who failed vision screening and underwent a school-based eye exam in the Northeast region of the United States during 2016–2022. Non-cycloplegic autorefraction and visual acuity measurements were used to categorize refractive error by type and severity. Main outcomes included any refractive error (at least −0.50D myopia, +0.50 hyperopia, 1.00D astigmatism, or 1.00D anisometropia), clinically significant refractive error (CSRE; more severe refractive error with decreased vision), and refractive amblyopia risk (RAR). Multivariable mixed-effects logistic regression was used to determine student- and school-level characteristics associated with refractive error outcomes. Results Of 103,159 included students who failed screening, 95,875 (92.9%) were analyzed. Overall prevalence of any refractive error was 94.2%, with 81.7% having CSRE. Pre-kindergarten & kindergarten students had the highest prevalence of CSRE (85.7%), which dropped to 77.0% by 3rd and 4th grade before rising with each higher grade level thereafter. Prevalence of RAR was 60.9% overall and highest in pre-kindergarten and kindergarten students (73.8%). Myopia was the most prevalent refractive error, followed by astigmatism, anisometropia, then hyperopia. The odds of hyperopia, astigmatism, and anisometropia decreased with higher grade level. Conclusion Over 80% of students who failed vision screening at a large school-based vision program had CSRE, and over 60% had RAR. Pre-kindergarten and kindergarten students had an especially high prevalence of RAR. Refractive error remained common in every grade level.

Refractive development II: Modelling normal and myopic eye growth.

During refractive development, eye growth is controlled by a combination of genetically pre-programmed processes and retinal feedback to minimise the refractive error. This work presents a basic differential model of how this process may take place. The description starts from two bi-exponential descriptions of the axial power Pax (or dioptric distance) and total refractive power Peye, the difference between which corresponds with the spherical refractive error S. This description is rewritten as an ordinary differential equation and supplemented by a retinal feedback function that combines retinal blur (closed loop) with a term describing excessive axial growth (open loop). This model is controlled by a total of 18 parameters that allow for a wide variety of developmental behaviours. The proposed model reproduces refractive development growth curves found in the literature for both healthy and myopic eyes. An early onset of myopisation, a large growth term and a high minimum for the crystalline lens power all lead to higher degrees of myopia. Assigning more importance to the feedback than to the pre-programmed growth makes the model more sensitive to myopogenic influences. Applying refractive corrections to the model, undercorrection is found to produce more myopia. The model compensates for a low-powered imposed lens and can return to (near) emmetropia if that imposed lens is removed quickly thereafter. Finally, simulating the effect of a diffuser leads to high myopia. Using a series of basic assumptions, the proposed model recreates many well-known experimental and clinical results about refractive development from the literature while placing them in a standardised context. This contributes to a broader understanding of the origins of refractive errors, and future versions may help in the development of solutions for myopia control.