Utility of retinoscopy to examine peripheral refraction

Purpose: This study explored whether retinoscopy (RET) provides comparable results of relative peripheral refraction (RPR) to open–field autorefractometry (AR) in myopic subjects.Methods: Peripheral refraction was measured in 20 myopic and 20 control adult subjects. Both central and peripheral refraction (20° nasal and temporal eccentricity) were measured using RET and open-field AR. Differences in the median central spherical equivalent (SE), median RPR, and median J45/J180 power vectors between the RET and AR techniques were analyzed. Moreover, Bland – Altman plots were used to assess the agreement between RET and AR methods for RPR measurements in MG. Results: For MG, the median RPR values were positive (hyperopic shift), and no significant differences were observed between the RET and AR techniques with respect to RPR measurement. In addition, we did not observe any significant differences in the RPR values between the nasal and temporal eccentricities for either the RET or AR technique for myopic subjects. There was also a significant correlation and agreement between the RET and AR technique for RPR measurements. With respect to central refraction, the median SE was slightly more positive for the RET than for the AR technique. Inside the CG, we also found significant correlation between the RET and AR technique for RPR measurements, and we observed a myopic shift in peripheral eccentricities. Conclusion: Our results show that retinoscopy may be a useful tool for objective measurements of RPR in myopic subjects and may be used interchangeably with the open-field AR method in everyday clinical practice. (AU)

Reduced retinol (vitamin A) and α-tocopherol (vitamin E) blood levels and increased myeloperoxidase (MPO) activity in children with high myopia.

The study assessed selected parameters of redox status in the plasma of patients suffering from high myopia (HM). Thirty-five children with mean age 13.7 ± 2.7 years with HM and 40 healthy children were included. Plasma redox status parameters were determined using colorimetric kits. The levels of retinol, α-tocopherol and coenzyme Q10 were determined with a high-performance liquid chromatograph. Negative correlations were observed between the concentrations of retinol and the axial length of the eye (r = - 0.514 p < 0.001). Increased myeloperoxidase (MPO) activity (p < 0.018), and decreased concentrations of retinol (p < 0.001) and α-tocopherol (p < 0.023) in patients with HM and the axial length of the eye > 26 mm compared to controls were established. Significantly lower retinol and α-tocopherol concentrations were found in patients with the axial length of the eye > 26 mm compared to those with the axial length of the eye ≤ 26 mm (p < 0.001, p < 0.021, respectively). Increased MPO activity in advanced stages of HM may confirm an inflammatory process in HM patients. Reduced retinol and α-tocopherol concentrations and their link to disease progression indicate a need for monitoring their levels and supplementation in children with HM.

[Analysis of factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma].

Objective: To investigate the factors affecting the progression of visual field defects in patients with myopia and primary open-angle glaucoma (POAG), and to clarify whether the factors vary in patients with different degrees of myopia. Method: An ambispective cohort study was conducted among patients diagnosed with myopia and POAG from the glaucoma outpatient department at the Zhongshan Ophthalmic Center of Sun Yat-sen University between January 2006 and January 2024. Based on the criteria of functional visual field progression, patients were divided into the progression group and non-progression group, and further divided into the low to moderate myopia subgroup and high myopia subgroup according to the degree of myopia. The patient age, gender, type of glaucoma (high tension glaucoma and normal tension glaucoma), spherical equivalent refraction, best corrected visual acuity (BCVA, recorded as the logarithm of the minimum angle of resolution), intraocular pressure (IOP), central corneal thickness, baseline visual field, history of ophthalmic surgery (corneal refractive surgery and glaucoma surgery), and number of anti-glaucoma medications were summarized. The generalized estimation equation was used for comparison between groups, and the Cox proportional hazards model was used to analyze the factors affecting the progression of visual field defects. Results: A total of 182 eyes from 106 patients were included in this study. There were 57 eyes in the progression group and 125 eyes in the non-progression group. Compared with the non-progression group, the progression group had the older age [43 (29, 53) years old], worse BCVA [0.05 (0.00, 0.17)], greater IOP fluctuation [1.8 (1.3, 2.9)mmHg(1 mmHg=0.133 kPa)], more common baseline central defects [52.6%(30/57)], higher visual field pattern standard deviations [8.92 (5.32, 12.00)dB], lower visual field index [77% (67%, 88%)], and more anti-glaucoma medications [35.1% (20/57) patients used three medications] (all P<0.05). The Cox proportional hazards models showed that the baseline moderate visual field defects [hazard ratio (HR)=2.33, 95% confidence interval (CI): 1.25 to 4.36, P=0.008], baseline central defects (HR=2.09, 95%CI: 1.11 to 3.93, P=0.022), older age (Model A, HR=1.03, 95%CI: 1.00 to 1.05, P=0.017; Model B, HR=1.02, 95%CI: 1.00 to 1.05, P=0.019), and greater IOP fluctuation (Model A, HR=1.54, 95%CI: 1.32 to 1.81, P<0.001; Model B, HR=1.49, 95%CI: 1.26 to 1.75, P<0.001) were risk factors for visual field progression. In the low to moderate myopia subgroup, the increased risk of progression was associated with baseline central defects (HR=5.74, 95%CI: 1.72 to 19.20, P=0.005), worse BCVA (Model A, HR=15.80, 95%CI: 2.07 to 121.00, P=0.008; Model B, HR=12.50, 95%CI: 2.65 to 58.70, P=0.001), and older age (Model A, HR=1.05, 95%CI: 1.02 to 1.08, P=0.002; Model B, HR=1.07, 95%CI: 1.03 to 1.11, P<0.001). In the high myopia subgroup, the increased risk of progression was associated with baseline moderate visual field defects (HR=2.35, 95%CI: 1.12 to 4.92, P=0.024) and greater IOP fluctuation (Model A, HR=1.50, 95%CI: 1.24 to 1.82, P<0.001; Model B, HR=1.52, 95%CI: 1.26 to 1.83, P<0.001). Conclusions: Age, IOP fluctuation, baseline moderate visual field defects, and baseline central defects were the factors affecting the progression of visual field defects in patients with myopia and POAG. There were differences in the influencing factors of visual field progression in patients with different degrees of myopia.

Effect of defocus incorporated multiple segments (DIMS) spectacle lenses on myopia progression in children: a retrospective analysis in a German real-life clinical setting.

OBJECTIVES: This retrospective analysis evaluates the treatment success of "Defocus Incorporated Multiple Segments" (DIMS) spectacle lenses in a real-life clinical setting in Germany. MATERIALS AND METHODS: Axial length (AL) and objective refraction of 166 eyes treated with DIMS at baseline and 12-month follow-up were analyzed. Annual AL growth rate within the range of physiological growth rate was considered a successful treatment. Myopia progression of ≥ -0.5 D/yr accounted as treatment success. Differences in percentages of treatment success of subgroups depending on baseline AL and age against treatment success of the total population were investigated. RESULTS: Considering all eyes, treatment success regarding AL growth and myopia progression was achieved in 46% and 65%, respectively. Male eyes with moderate AL showed treatment success in a higher proportion (73%, p < 0.01; 89%, p < 0.01); eyes with high AL showed treatment success in a lower proportion (25%, p < 0.01; 51%, n.s.). Female eyes showed the same trend but without statistical significance (moderate AL: 49%; 68%; high AL: 40%; 62%). Younger children showed treatment success in a lower proportion (male: 11%, p < 0.01; 38%, p < 0.05; female: 25%, p < 0.01; 42%, p < 0.01). Older children showed treatment success in a higher proportion (male: 60%, p < 0.05; 78% p < 0.05; female: 53%, n.s.; 77% p < 0.05). CONCLUSIONS: Eyes with moderate baseline AL and of older children showed treatment success after 12 months of DIMS treatment. Eyes with a high baseline AL and of younger children showed treatment success in a smaller proportion, therefore combination treatment should be considered. In future studies, males and females should be assessed separately.

Prevalence, sociodemographic risk factors, and coverage of myopia correction among adolescent students in the central region of Portugal.

BACKGROUND: Knowing the prevalence of myopia at school age is essential to implement preventive measures and appropriate interventions, ensure access to vision care, promote a healthier educational environment and improve academic performance. The purpose of this study was to determine the prevalence of myopia and its associated sociodemographic risk factors, as well as to estimate the coverage of myopia correction among adolescents in center of Portugal. METHODS: This cross-sectional study evaluated 1115 adolescents from the 5th to the 9th year of school, with an average of 12.9 years (SD = 1.5) ranging from 10.0 to 18.0 years. Optometric evaluations were carried out in a school environment and consisted of the evaluation of distance visual acuity, assessed using a logarithmic visual acuity chart (ETDRS charts 1 and 2) at 4 m, and measured by refractive error with a pediatric autorefractometer (Plusoptix), by non-cycloplegic. Myopia was defined as spherical equivalent (SE ≤ -0.50 diopter (D)) and uncorrected visual acuity (UVA ≤ 95VAR). Adjusted logistic regression analysis was applied to investigate risk factors. RESULTS: We found a myopia rate of 21.5% and a high myopia rate of 1.4%. Higher school level and attendance at urban schools were associated with myopia, but no association was found with age or sex. Only 34.6% of myopic adolescents use the best optical correction and 26.4% do not use any type of optical correction. CONCLUSIONS: Data on the prevalence of refractive problems in Portugal are scarce and heterogeneous. This study, although regional, provides a valuable contribution with a clear and reproducible methodology, following international guidelines and filling gaps in the existing literature. The results show that the rate of myopia in this age group is similar to reports from other European studies. The high rate of adolescents with uncorrected or under-corrected myopia in Portugal is a problem that deserves attention.

Comprehensive assessment of corneal microstructural changes following V4c implantable collamer lens surgery using in vivo confocal microscopy.

BACKGROUND: Implantable Collamer Lense (ICL) presents a viable alternative to conventional refractive surgeries, but their impact on corneal microstructure remains unclear. By employing in vivo confocal microscopy (IVCM), we examined changes in stromal and endothelial cells following the insertion of V4c ICLs, with the goal of enhancing post-surgical care and outcomes. METHODS: In this longitudinal investigation, we conducted detailed preoperative assessments on 103 eyes from 53 participants. Follow-up evaluations were carried out after surgery at set intervals: one day, one week, one month, three months, six months, and twelve months. We used IVCM to analyze changes in stromal and endothelial cells. To assess differences between pre- and post-surgery variables and to investigate correlations with age, axial length (AL), and spherical equivalent refraction (SER), we applied a repeated measures mixed-effects model, with statistical significance set at P < 0.05. RESULTS: No vision-threatening complications were reported post-surgery. Significant reductions in stromal cell density (SCD) were observed postoperatively, with anterior and mid- SCD reaching their lowest values at 3 months and posterior SCD at 1 month, remaining below baseline at 12 months. endothelial cell density (ECD) and percentage of hexagonal cells (PHC) decreased initially, recovering by 12 months. Conversely, endothelial cellular area (ECA) and coefficient of variation of cell size (CoV) increased postoperatively, with the most significant change at 1 week. Endothelial deposits were detected in 49 of 101 eyes on postoperative day 1, half of them were absorbed within 3 months post-surgery. Changes in posterior SCD were negatively related to AL, while AL, SER, lens thickness showed associated with endothelium changes. CONCLUSION: Our findings elucidate the corneal microstructural changes following V4c ICL implantation, particularly the significant early reductions in stromal and endothelial cell densities. We recommend careful management of viscoelastics during surgery to minimize endothelial deposits that may harm the endothelium. Enhanced early postoperative monitoring and these surgical adjustments can lead to improved surgical and post-surgical care, ultimately supporting better patient recovery.

Lifetime cost-effectiveness of myopia control intervention for the children population.

Background: Myopia is a common eye condition and projected to affect half of the global population by 2050. Controlling its progression during childhood may prevent associated ocular diseases in later life. Certain interventions retard myopia progression but their long-term costs and consequences are not well understood. We evaluated the cost-effectiveness of myopia control via an optical approach using the Defocus Incorporated Multiple Segments (DIMS) lens over a lifetime. Methods: We constructed an individual-based, state-transition model to simulate 1) the development and progression of myopia in childhood with and without control and 2) the impact of myopia on the development of four sight-threatening complications in adulthood. We compared strategies of myopia control with 100% uptake vs. no myopia control from the societal perspective to determine whether myopia control is value for money. Results: With myopia control, the cumulative prevalence of high myopia was relatively reduced by 44.7% (5.9 vs. 10.7%) and severe visual impairment by 19.2% (2.2 vs. 2.7%) compared to no myopia control. The lifetime cost per quality-adjusted life year gained was 26 407 US dollars (USD) and is considered cost-effective compared to the threshold recommended by the World Health Organization (WHO) of one times annual per capita gross domestic product (48 359 USD). Probabilistic sensitivity analysis showed that myopia control had an 87% likelihood of being cost-effective at the WHO threshold. Conclusions: Myopia control is cost-effective when provided to all eligible children. Further investigation is required to determine if it is cost-effective for the government to subsidise myopia control in order to maximise access.

Administration of Nicotine Can Inhibit Myopic Growth in Animal Models.

Purpose: While previously investigating the mechanism by which atropine inhibits ocular growth, we observed that stimulation of nicotinic receptors can inhibit experimental myopia. This study expands on that preliminary finding and investigates the safety and efficacy of nicotinic stimulation in the inhibition of ocular growth. Methods: Nicotine's ability to inhibit form-deprivation myopia (FDM), following intravitreal injection (9 chicks per group) or topical application (6 chicks per group), was investigated over three doses. The ability of nicotine to inhibit lens-induced myopia (LIM) was also tested (in 12 chicks). For ocular safety, following 4 weeks of topical treatment with nicotine (n = 10), pupillary reflex, intraocular pressure, corneal curvature/thickness, lens thickness, retinal health (retinal thickness/cell apoptosis), as well as retinal function (electroretinogram recordings) were assessed. We also examined the effects of nicotine on non-ocular autonomic functions in both chicks (n = 5) and mice (n = 5). Results: Nicotine was observed to significantly inhibit the development of FDM in chicks when administered as an intravitreal injection (P < 0.05) or topical eye drops (P < 0.05), albeit not in a dose-dependent manner. Nicotine also inhibited LIM (P < 0.05) to a similar degree to that seen for FDM. Although ocular health was (for the most part) unaffected by nicotine, the highest topical dose induced a temporary reduction in cardiorespiratory output (P < 0.05). Conclusions: Nicotine, administered as an intravitreal injection or topical eye drop, significantly inhibits the development of experimental myopia. Although the anti-myopic effects observed presently are interesting, the well-reported side effects (expanded on presently) and addictive properties of nicotine would preclude its clinical use.

Peripheral Superficial Retina Vascular Density and Area of Radial Peripapillary Capillaries Changes in Myopic Individuals: A Wide-Field OCT Angiography Study.

Purpose: Using swept-source optical coherence tomography (SS-OCT) to explore the effect of high myopia on superficial retina vascular density (SVD) of the peripheral region and the area of radial peripapillary capillaries (RPCs). Methods: In this cross-sectional study, a total of 91 volunteers (34 male subjects and 57 female subjects) were recruited and 34 individuals in the high myopic group (group A) and 57 individuals in the low myopic group (group B). Using the wide-field OCT-angiography (OCTA; 24 × 20 mm, 120 degrees angular field) compared the peripheral SVD and the area of RPC between the two groups and investigated its correlation with ocular axial length and diopter. Results: Peripheral SVD of group B around the supratemporal (SVD1), supranasal (SVD2), infratemporal (SVD3), and infranasal (SVD4) directions were significantly higher than those of group A (all P < 0.05). The RPC area of group B around the supranasal (RPC2) and infranasal (RPC4) were significantly larger than that of group A (all P < 0.01). Ocular axial length and diopter were significantly correlated with SVD2 and SVD4 (all P < 0.05), and they also have a significant correlation with the supratemporal (RPC1), RPC2, and RPC4 (all P < 0.05). Conclusions: Peripheral SVD was decreased and the RPC area was mainly reduced on the nasal side in the high myopic group. Peripheral SVD and area of RPC are significantly correlated with ocular axial length and diopter. Translational Relevance: The wide-field OCTA can be used for new detection of myopia's impact on the retinal peripheral SVD and area of peripapillary RPC, offering new insights into the progression of myopia.

[Relationship between academic procrastination and depression in myopia junior middle school students in a district of Chongqing in 2022].

OBJECTIVE: To understand the relationship between academic delay and depression in myopic junior high school students. METHODS: Medical visual acuity examination(including far-vision examination and dioptometry) and questionnaire survey(including Middle School students' Academic Procrastination Questionnaire and Childhood Depression Scale) were conducted among 1752 junior middle school students in a district of Chongqing in June 2022. Difference analysis, correlation analysis and binary Logistic regression analysis were performed on the data obtained from myopic students. RESULTS: 1116(63.69%) students with myopia were detected, 405 students with academic delay and 1289 students with depression. Among them, 266(65.68%) and 835(64.78%) were nearsighted due to academic procrastination and depression. There were significant differences in academic procrastination and depression between myopic and non-myopic students(P<0.01). Moreover, myopic junior high school students have a greater risk of academic procrastination and depression(OR=4.94, 95%CI 3.04-8.01). CONCLUSION: Myopic junior high school students are more likely to have academic delay and depression.

Correlation analysis of myopia and dietary factors among primary and secondary school students in Shenyang, China.

Currently, the global prevalence of myopia is high and on the rise, seriously affecting the health of students. Studies have suggested that dietary factors may be associated with the occurrence and development of myopia, but the results are inconsistent. This survey aims to analyze the correlation between dietary factors and myopia while controlling for more confounding factors. A multi-stage stratified cluster sampling method was performed to select 10,619 primary and secondary school students in Shenyang for visual examination, and questionnaires were administered to 6974 of them. Logistic regression was performed with myopia as the dependent variable and the variables with p < 0.1 in the univariate analysis as independent variables. Sensitivity analysis was conducted using propensity score matching. The results showed that the overall prevalence of myopia among primary and secondary school students in Shenyang was 59.1%, with mild myopia predominating. Students who ate fresh fruits two or more times a day had a 0.69 times lower risk of myopia compared to those who did not eat fruits (95% CI 0.50-0.97). However, subgroup analysis demonstrated that this protective effect was only significant for male students, with an OR of 0.59 (95% CI 0.38-0.91). Moreover, female students who consumed sugary beverages once or more a day had a 1.8 times higher risk of myopia compared to those who did not consume sugary beverages (95% CI 1.03-3.15). Vegetable consumption, intake of fried foods, and breakfast habits were not significantly associated with myopia. In summary, excessive consumption of sugary beverages could increase the risk of myopia, especially in female students, whereas fruit intake contributed to reducing the risk of myopia, particularly in male students.

Corneal biomechanical properties and potential influencing factors in varying degrees of myopia.

To compare the corneal biomechanical parameters measured by Corvis ST in subjects with varying degrees of myopia. And the factors that may affect corneal biomechanical properties were also investigated. Participants in this prospective cross-sectional study were classified into three groups according to spherical equivalent (SE) and axial length (AL): Non-myopia (NM, SE > - 0.50 D and AL < 26 mm), Mild-to-moderate myopia (MM, - 6.00 D < SE ≤ - 0.50 D and AL < 26 mm), high myopia (HM, SE ≤ - 6.00 D or AL ≥ 26 mm). Ten corneal biomechanical parameters were finally included. Linear mixed-effects model accounting for using both eyes in the same participant was carried out to evaluate how the corneal biomechanical parameter was influenced by varying degrees of myopia after adjusting for biomechanically corrected intraocular pressure (bIOP) and central corneal thickness (CCT). Further, multiple linear regression was performed to explore the correlation between corneal biomechanical parameter and SE, AL, bIOP or CCT. A total of 304 eyes from 224 healthy myopic subjects were recorded. There were 95 eyes with NM, 122 eyes with MM, and 87 eyes with HM. After adjusting for bIOP and CCT, eyes with high myopia showed shorter highest concavity time (HC-time, p = 0.025), greater peak distance (PD, p = 0.001), greater deflection amplitude (DA-Max, p = 0.002), smaller whole eye movement (WEM-Max, p < 0.001) and reduced stiffness parameter (SP-A1, p < 0.001). Multiple regression analysis showed that five parameters (HC-time, p < 0.001; PD, p < 0.001; DA-Max, p = 0.001; WEM-Max, p < 0.001; and SP-A1, p < 0.001) of Corvis ST were significantly correlated with AL, and one parameter (Corvis biomechanical index, p = 0.016) has significant relationship with SE. With the increase of myopia, significant changes in several corneal biomechanical parameters indicated a progressive decrease in corneal stiffness, independent of bIOP and CCT. Corneal biomechanical parameters may be predictors of scleral mechanical strength in high myopia, which has certain application value in clinical management of myopia.

VEGFA may be a potential marker of myopic choroidal thickness and vascular density changes.

To evaluate the changes of choroidal thickness (CT) and blood flow related to myopia, and its effects of vascular endothelial growth factor (VEGFA) on choroidal vessels in myopia. Subjects were included and divided into emmetropia (EM), non-high myopia (Non-HM) and high myopia (HM) groups. we measured choroidal thickness (CT), choriocapillaris vessel density (VD), and VEGFA content in tears in humans (137 subjects for CT, VD and 84 for tear) and detected the role of VEGFA in the choroid in form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs were divided into control and FDM groups, and the expression changes of choroidal vessels and VEGFA were observed and compared using immunohistochemistry and Western blotting. Twenty-one guinea pigs were divided into control, FDM + Vehicle and FDM + Conbercept groups. The changes of diopter, axis length and choroidal vessels after intravitreal injection of Conbercept were observed. There were significant differences in CT and VD among the three groups (p < 0.05). VEGFA levels in tears were significantly lower in the myopic groups, with a decreasing trend from EM to Non-HM to HM. The choroidal vascular area fraction of FDM decreased compared to the control group. FDM guinea pigs exhibited reduced choroidal vasculature and significant downregulation of VEGFA expression. Following intravitreal injection of conbercept, the FDM + Conbercept group showed greater myopia, longer axial length, and lower choroidal vascular area fraction compared to the control group. VEGFA may participate in the regulation of choroidal blood vessels and blood flow in the progression of myopia. The reduction in VEGFA may accelerates the progression of myopia.

12-Month Visual and Refractive Outcomes of Topography-guided Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism.

PURPOSE: To report 12-month visual and refractive outcomes following topography-guided femtosecond laser-assisted laser in situ keratomileusis (LASIK) for myopia and compound myopic astigmatism correction. METHODS: This prospective, single-center observational study was conducted in an outpatient clinical practice at the Stanford University Byers Eye Institute in Palo Alto, California. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, 5% and 25% contrast sensitivity CDVA, and manifest refraction following topography-guided femtosecond laser-assisted LASIK were assessed. Refractive measurements were used to perform a vector analysis. RESULTS: Sixty eyes of 30 patients (mean age: 32.8 ± 7.0 years; range: 23 to 52 years) undergoing topography-guided LASIK for the correction of myopia and compound myopic astigmatism were analyzed. Mean postoperative UDVA was -0.09 ± 0.10 logarithm of the minimum angle of resolution (logMAR) at 12 months. Mean preoperative CDVA was -0.09 ± 0.09 and -0.13 ± 0.08 logMAR at postoperative 12 months. At 12 months, 26.9% of eyes had gained one or more lines of postoperative UDVA compared to baseline CDVA. Mean pre-operative 5% contrast sensitivity CDVA was 0.68 ± 0.07 and 0.64 ± 0.12 logMAR at 12 months (P = .014) following LASIK. CONCLUSIONS: Topography-guided LASIK for myopia and myopic astigmatism correction provided excellent visual and refractive outcomes that were predictable, precise, and stable up to 12 months postoperatively. [J Refract Surg. 2024;40(9):e595-e603.].

Effect of Posterior Keratometry and Corneal Radius Ratio on the Accuracy of Intraocular Lens Formulas After Myopic LASIK/PRK.

PURPOSE: To investigate the impact of back-to-front corneal radius ratio (B/F ratio) and posterior keratometry (PK) on the accuracy of intraocular lens power calculation formulas in eyes after myopic laser in situ keratomileusis (LASIK)/photorefractive keratectomy (PRK) surgery. METHODS: A retrospective, consecutive case series study included 101 patients (132 eyes) with cataract after myopic LASIK/PRK. Mean prediction error (PE), mean absolute PE (MAE), median absolute error (MedAE), and the percentage of eyes within ±0.25, ±0.50, and ±1.00 diopters (D) of PE were determined. RESULTS: The Barrett True K-TK formula exhibited the lowest MAE (0.59 D) and MedAE (0.48 D) and the highest percentage of eyes within ±0.50 D of PE (54.55%) in total. In eyes with a B/F ratio of 0.70 or less and PK of -5.70 D or greater, the Potvin-Hill formula displayed the lowest MAE (0.46 to 0.67 D). CONCLUSIONS: The Barrett True-TK exhibited the highest prediction accuracy in eyes after myopic LASIK/PRK overall. However, for eyes with a low B/F ratio and flat PK, the Potvin-Hill performed best. [J Refract Surg. 2024;40(9):e635-e644.].

Low Contrast Acuity Outcomes After SMILE and LASIK.

PURPOSE: To compare early visual quality of small incision lenticule extraction (SMILE) versus laser in situ keratomileusis (LASIK) in terms of low contrast acuity. METHODS: A secondary analysis was performed using a harmonized dataset derived from two completed prospective cohort studies on active-duty military service members undergoing either SMILE (n = 37), wavefront-guided (WFG) LASIK (n = 51), or wavefront-optimized (WFO) LASIK (n = 56). Night vision and photopic and mesopic low contrast visual acuity (LCVA) up to 3 months postoperatively were compared between groups. RESULTS: Compared to SMILE-treated eyes, WFG LASIK-treated eyes had significantly better night vision and photopic LCVA at 1 month postoperatively (beta = -0.039, P = .016; beta = -0.043, P = .007, respectively). WFO LASIK-treated eyes had significantly better photopic LCVA at 1 month postoperatively (beta = -0.039, P = .012) but had worse mesopic LCVA at 3 months postoperatively (beta = 0.033, P = .015) versus SMILE-treated eyes. CONCLUSIONS: SMILE and LASIK, on either a WFG or WFO laser platform, yielded excellent outcomes, but LCVA seemed to recover quicker following LASIK compared to SMILE. [J Refract Surg. 2024;40(9):e667-e671.].

Comparison of long-term changes in the effective optical zone following SMILE and FS-LASIK for moderate and high myopia.

BACKGROUND: Visual quality after corneal refractive surgery is linked to the postoperative effective optical zone (EOZ). This study aims to compare long-term changes in the EOZ following small incision lenticule extraction (SMILE) and femtosecond laser-assisted in-situ keratomileusis (FS-LASIK) for moderate and high myopia. METHODS: This study included 42 patients (72 eyes) who underwent either SMILE (36 eyes) or FS-LASIK (36 eyes). A custom software program based on the tangential curvature difference map of the Pentacam HR (Oculus Optikgeräte GmbH) was used to define the EOZ at 3 and 7 years postoperatively. The EOZ, its chronological changes compared to the programmed optical zone (POZ), and the corneal wavefront aberrations following SMILE and FS-LASIK were analyzed. Correlations between the EOZ changes and relevant parameters were evaluated. RESULTS: Three years postoperatively, EOZ following SMILE and FS-LASIK were 5.13 ± 0.27 mm and 4.70 ± 0.24 mm (P < 0.001), respectively. Seven years postoperatively, EOZ following SMILE and FS-LASIK decreased to 5.03 ± 0.28 mm and 4.63 ± 0.23 mm (P < 0.001), respectively. At postoperative 7 years, the percentages of EOZ/POZ were negatively correlated with Q-value changes (ß = -5.120, P = 0.009) following SMILE and positively correlated with the cylinder correction (ß = 1.184, P = 0.004) following FS-LASIK. The induced spherical aberrations in the SMILE group were less than those in the FS-LASIK group (P < 0.05) and were negatively correlated with the EOZ/POZ (ß = -16.653, P < 0.001). CONCLUSIONS: The EOZ following SMILE was larger than that following FS-LASIK in the long postoperative term for moderate and high myopia. Furthermore, a continual reduction in the EOZ was noted after both surgical modalities.

Loss of ON-Pathway Function in Mice Lacking Lrit3 Decreases Recovery From Lens-Induced Myopia.

Purpose: To determine whether the Lrit3-/- mouse model of complete congenital stationary night blindness with an ON-pathway defect harbors myopic features and whether the genetic defect influences the recovery from lens-induced myopia. Methods: Retinal levels of dopamine (DA) and 3,4 dihydroxyphenylacetic acid (DOPAC) from adult isolated Lrit3-/- retinas were quantified using ultra performance liquid chromatography after light adaptation. Natural refractive development of Lrit3-/- mice was measured from three weeks to nine weeks of age using an infrared photorefractometer. Susceptibility to myopia induction was assessed using a lens-induced myopia protocol with -25 D lenses placed in front of the right eye of the animals for three weeks; the mean interocular shift was measured with an infrared photorefractometer after two and three weeks of goggling and after one and two weeks after removal of goggles. Results: Compared to wild-type littermates (Lrit3+/+), both DA and DOPAC were drastically reduced in Lrit3-/- retinas. Natural refractive development was normal but Lrit3-/- mice showed a higher myopic shift and a lower ability to recover from induced myopia. Conclusions: Our data consolidate the link between ON pathway defect altered dopaminergic signaling and myopia. We document for the first time the role of ON pathway on the recovery from myopia induction.

The impact of different postures on acute intraocular pressure and accommodation responses during reading.

INTRODUCTION: To investigate the effects of different reading postures on intraocular pressure (IOP) and near-work-induced transient myopia (NITM) in children with myopia. METHODS: Sixty myopic children were instructed to read a book text placed at 33 cm for 30 min with two different reading postures: head bowed and head upright postures. The participants' IOP and NITM were assessed using a rebound tonometer and an open-field autorefractor. The measurement of IOP was conducted prior to reading, during reading sessions (at 5, 10, 20, and 30-min intervals), and after a 5-min recovery period. RESULTS: For the head bowed posture, the mean baseline IOP was 16.13 ± 2.47 mmHg. A significant rise in IOP was observed after 5 min of reading (17.17 ± 2.97 mmHg; +1.03 ± 2.29 mmHg; p = 0.014). Subsequent measurements revealed a further increase after 20 min (17.87 ± 2.90 mmHg; +1.73 ± 2.58 mmHg; p < 0.001), which continued to persist even after 30 min of reading (17.57 ± 3.46 mmHg; +1.43 ± 2.66 mmHg; p = 0.002). The IOP at different time points measured in the head upright posture did not show any significant difference in comparison to the baseline measurement (all p = 1.000). Compared to reading with the head upright, reading with the head bowed resulted in a greater increase in IOP at each time point (p < 0.05). Furthermore, the NITM was higher for reading with the head bowed than for reading with head upright at 30 min (-0.24 ± 0.53 D vs. -0.12 ± 0.47 D, p = 0.038). CONCLUSION: Reading in a head bowed position resulted in greater increases in IOP and NITM compared to reading in a head upright posture.

The effect of different potency glucocorticosteroids treatments on tear inflammatory factors and corneal optical density after femtosecond-assisted laser in situ keratomileusis.

To assess the impact of glucocorticosteroids with varying potencies on inflammatory mediators in tears and corneal optical density after femtosecond-assisted laser in situ keratomileusis (FS-LASIK). In a prospective study, 110 patients (220 eyes) who underwent FS-LASIK were divided into 2 groups: 55 patients (110 eyes) received dexamethasone, and another 55 patients (110 eyes) received fluorometholone. Visual acuity, intraocular pressure, and corneal optical density were measured before, 1 week, and 1 month after surgery. Tear fluid samples were also collected to assess expression levels of TNF-α, IL-1α, IL-6, and TGF-ß1. One week after the procedure, the dexamethasone group exhibited elevated intraocular pressure (IOP) levels (P > .05) and a decreased expression of TNF-α in tears (P < .001) compared to the fluorometholone group. Within the 0 to 2 mm range from the corneal apex, the anterior corneal layer's optical density in the fluorometholone group surpassed that of the dexamethasone group (P < .05). At 1 month post-surgery, the IOP in the fluorometholone group was higher than that in the dexamethasone group (P < .05). In both the 0 to 2 mm and 2 to 6 mm intervals from the corneal apex, the optical density of the anterior corneal layer was significantly higher in the fluorometholone group compared to the dexamethasone group (P < .05). There was no statistically significant difference in visual acuity between the 2 groups at any postoperative time point. Short-term use of potent corticosteroids after FS-LASIK can swiftly address ocular surface inflammation, enhance corneal wound healing, reduce corneal edema, and accelerate the restoration of corneal transparency, in contrast to prolonged use of milder corticosteroids post-surgery.