The Parameters Governing the Anti-Myopia Efficacy of Chromatically Simulated Myopic Defocus in Tree Shrews.

Purpose: We previously showed that exposing tree shrews (Tupaia belangeri, small diurnal mammals closely related to primates) to chromatically simulated myopic defocus (CSMD) counteracted small-cage myopia and instead induced hyperopia (approximately +4 diopters [D]). Here, we explored the parameters of this effect. Methods: Tree shrews were exposed to the following interventions for 11 days: (1) rearing in closed (n = 7) or open (n = 6) small cages; (2) exposed to a video display of Maltese cross images with CSMD combined with overhead lighting (n = 4); (3) exposed to a video display of Maltese cross images with zero blue contrast ("flat blue," n = 8); and (4) exposed to a video display of black and white grayscale tree images with different spatial filtering (blue pixels lowpass <1 and <2 cycles per degree [CPD]) for the CSMD. Results: (1) Tree shrews kept in closed cages, but not open cages, developed myopia. (2) Overhead illumination reduced the hyperopia induced by CSMD. (3) Zero-blue contrast produced hyperopia but slightly less than the CSMD. (4) Both of the CSMD tree images counteracted small cage myopia, but the one low pass filtering blue <1 CPD was more effective at inducing hyperopia. Conclusions: Any pattern with reduced blue contrast at and below approximately 1 CPD counteracts myopia/promotes hyperopia, but maximal effectiveness may require that the video display be the brightest object in the environment. Translational Relevance: Chromatically simulated myopic blur might be a powerful anti-myopia therapy in children, but the parameter selection could be critical. Issues for translation to humans are discussed.

[Quantitative comparison of binocular suppression of patients with anisometropic amblyopia and ametropic amblyopia].

Objective: To explore the differences in clinical characteristics and interocular interactions between patients with anisometropic amblyopia and ametropic amblyopia. Methods: Cross-sectional study. The newly diagnosed anisometropic (the binocular difference in spherical equivalent≥1.00 D) amblyopia patients and ametropic amblyopia patients (aged 4 to 6 years) in Beijing Tongren Hospital from January 2020 to December 2022 were involved. Patients were further categorized by the refractive status after cycloplegia, including hyperopia, myopia, astigmatism, hyperopia with astigmatism, myopia with astigmatism, mild anisometropia and severe anisometropia. Quantitative measurements of best-corrected visual acuity (logMAR), stereoacuity (transformed to log units), perceptual eye position and interocular suppression were performed, and the differences between groups were analyzed. The rank sum test was used for statistical evaluation. Results: The average age of 45 ametropic amblyopia patients (21 males and 24 females) and 84 anisometropic amblyopia patients (48 males and 36 females) was 5.0 (4.0, 5.0) years and 5.0 (4.0, 6.0) years, respectively. The interocular differences in spherical equivalent [2.56 (1.50, 4.19) D vs. 0.25 (0.13, 0.56) D] and best-corrected visual acuity [0.40 (0.18, 0.70) logMAR vs. 0.07 (0.00, 0.12) logMAR] were larger in patients with anisometropic amblyopia than those with ametropic amblyopia. The anisometropic amblyopia patients had worse stereoacuity [2.60 (2.00, 2.90) log arcsec vs. 2.00 (2.00, 2.30) log arcsec] and deeper suppression [20.0% (13.3%, 40.0%) vs. 10.0% (0, 23.3%)], compared with the ametropic amblyopia patients. The differences were all statistically significant (P<0.05). The suppression and stereoacuity between patients with hyperopic anisometropic amblyopia [suppression, 30.0% (17.5%, 50.0%); stereoacuity, 2.90 (2.30, 2.90) log arcsec] and astigmatic anisometropic amblyopia [suppression, 10.0% (0, 20.0%); stereoacuity, 2.00 (2.00, 2.30) log arcsec] were significantly different (P<0.05). The differences of suppression and stereoacuity between patients with severe (binocular difference in spherical equivalent>2.50 D) [suppression, 30.0% (20.0%, 53.3%); stereoacuity, 2.90 (2.57, 2.90) log arcsec] and mild anisometropia [suppression, 20.0% (0, 30.0%); stereoacuity, 2.00 (2.00, 2.90) log arcsec] were also statistically significant (P<0.05). Conclusions: Patients with anisometropic amblyopia have deeper binocular suppression, worse stereoacuity and more severe binocular interaction abnormality than those with ametropic amblyopia. The severity of anisometropia affects the degree of the interaction abnormality.

Immediate Sequential Bilateral Implantable Collamer Lens Surgery Is Safe and Effective.

PURPOSE: To assess the clinical outcomes and safety profiles of patients who underwent immediate sequential bilateral phakic lens surgery. METHODS: This retrospective multicenter study included 254 consecutive patients (508 eyes) who underwent bilateral same-day Implantable Collamer Lens (ICL) (STAAR Surgical) surgery. The authors focused on 1-year postoperative clinical outcomes and adverse events. RESULTS: In the initial cohort, 176 patients (352 eyes) met inclusion criteria. Of these, 335 eyes underwent myopic ICL placement, and 17 eyes received a hyperopic ICL. Notably, 87% of eyes achieved ±0.50 diopters (D) and 95% achieved ±1.00 D of the intended refraction. One year postoperatively, 78% of eyes demonstrated optimal vaulting (250 to 750 µm), with a significant 19% reduction in vaulting observed over the 12 months (P < .001). Only minor adverse events, including early cataract formation (1 case), secondary toric ICL rotation (3 cases), and ICL exchange due to inappropriate vaulting (6 cases), were noted. CONCLUSIONS: The findings corroborate the safety and efficacy of immediate sequential bilateral phakic lens surgery and indicate its potential as a treatment option. The low incidence of minor adverse events further reinforces its favorable safety profile. [J Refract Surg. 2024;40(5):e313-e320.].

Uneven Corneal Epithelial Redistribution After Femtosecond Laser-Assisted Lenticule Intrastromal Keratoplasty in Correcting Moderate-to-High Hyperopia.

PURPOSE: To evaluate the characteristic of corrective epithelial thickness after femtosecond laser-assisted lenticule intrastromal keratoplasty (LIKE) to correct moderate-to-high hyperopia. METHODS: The prospective case series study of the LIKE procedure was performed to correct moderate-to-high hyperopia. The epithelial thickness map was generated by anterior segment optical coherence tomography (AS-OCT) in the corneal central 9-mm zone. Keratometry and corneal higher order aberrations were analyzed by Pentacam (Oculus Optikgeräte GmbH) preoperatively and postoperatively. RESULTS: In the 26 eyes of 13 participants who underwent the LIKE procedure for moderate-to-high hyperopia, the attempted spherical equivalence (SEQ) was +6.50 ± 1.09 diopters (D). Compared to the preoperative epithelial thickness maps, the postoperative epithelial thickness had become significantly thinner in the central 5-mm zone; the difference was 6 to 7 µm. The paracentral epithelium performed nonuniform remodeling; the thinnest epithelial thickness was located in the inferotemporal section, which has the greatest difference from the superonasal; the difference between these two was approximately 3 µm. Through correlation analysis, it was found that the sections with thinner epithelium were significantly related to corneal curvature and corneal vertical coma. CONCLUSIONS: The LIKE procedure can be used to correct moderate-to-high hyperopia. This study further indicated the epithelial remodeling characteristic after the LIKE procedure: the central and paracentral corneal epithelial thickness becomes thinner, and the epithelial thickness distributes non-uniformly, which may be the important factor of the postoperative curvature asymmetric distribution and induction of corneal vertical coma. [J Refract Surg. 2024;40(5):e321-e327.].

Peripheral Choroidal Response to Localized Defocus Blur: Influence of Native Peripheral Aberrations.

Purpose: This study aims to examine the short-term peripheral choroidal thickness (PChT) response to signed defocus blur, both with and without native peripheral aberrations. This examination will provide insights into the role of peripheral aberration in detecting signs of defocus. Methods: The peripheral retina (temporal 15°) of the right eye was exposed to a localized video stimulus in 11 young adults. An adaptive optics system induced 2D myopic or hyperopic defocus onto the stimulus, with or without correcting native peripheral ocular aberrations (adaptive optics [AO] or NoAO defocus conditions). Choroidal scans were captured using Heidelberg Spectralis OCT at baseline, exposure (10, 20, and 30 minutes), and recovery phases (4, 8, and 15 minutes). Neural network-based automated MATLAB segmentation program measured PChT changes from OCT scans, and statistical analysis evaluated the effects of different optical conditions over time. Results: During the exposure phase, NoAO myopic and hyperopic defocus conditions exhibited distinct bidirectional PChT alterations, showing average thickening (10.0 ± 5.3 µm) and thinning (-9.1 ± 5.5 µm), respectively. In contrast, induced AO defocus conditions did not demonstrate a significant change from baseline. PChT recovery to baseline occurred for all conditions. The unexposed fovea did not show any significant ChT change, indicating a localized ChT response to retinal blur. Conclusions: We discovered that the PChT response serves as a marker for detecting peripheral retinal myopic and hyperopic defocus blur, especially in the presence of peripheral aberrations. These findings highlight the significant role of peripheral oriented blur in cueing peripheral defocus sign detection.

Peripheral Refraction Using Ancillary Retinoscope Component (P-ARC).

Purpose: To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor. Methods: Fifty young adults (mean age, 24 ± 3 years) participated in this study. Two masked, experienced senior examiners carried out central refraction and peripheral refraction at the temporal 22° (T22°) and nasal 22° (N22°) eccentricities. Peripheral refraction techniques were (a) peripheral refraction using ancillary retinoscope component (P-ARC), (b) retinoscopy with eye rotation, and (c) open-field autorefractor. Peripheral refraction with retinoscopy values was compared with an open-field autorefractor (Shinn Nippon NVision-K) to assess the agreement. All measurements were taken from the right eye under noncycloplegic conditions. Results: The mean difference ±95% limits of agreement of peripheral refraction values obtained using P-ARC from T22° (+0.11 diopters [D] ± 1.20 D; P = 0.20) or N22° (+0.13 D ± 1.16 D; P = 0.13) were comparable with open-field autorefractor. The eye rotation technique compared to autorefractor showed a significant difference for T22° (+0.30 D ± 1.26 D; P = 0.002); however, there was an agreement for N22° (+0.14 D ± 1.16 D; P = 0.10). With respect to the identification of peripheral refraction patterns, examiners were able to identify relative peripheral hyperopia in most of the participants (77%). Conclusions: Peripheral refraction with P-ARC was comparable with open-field autorefractor at T22° and N22° eccentricities. Peripheral retinoscopy techniques can be another approache for estimating and identifying peripheral refraction and its patterns in a regular clinical setting. Translational Relevance: Retinoscope with P-ARC has high potential to guide and enable eye care practitioners to perform peripheral refraction and identify peripheral refraction patterns for effective myopia management.

[A study on the distribution characteristics of peripheral retinal defocus in children and adolescents].

Objective: To explore the distribution characteristics of peripheral retinal defocus in children and adolescents. Methods: This cross-sectional study included 500 individuals aged 3 to 18 years, who visited the People's Hospital of Lincang, the First Affiliated Hospital of Dali University and Dali Ophthalmology Hospital between January and December 2021. Data of the right eye of each participant was analyzed. There were 226 males (45.20%) and 274 females (54.80%), with an average age of (10.79±3.79) years. All participants underwent post-cycloplegic refraction, optical biometry, and intraocular pressure measurement to obtain spherical equivalent, average corneal curvature, axial length, and intraocular pressure. Multispectral refraction topography was performed to obtain topographic maps and values at various field angles and orientations of peripheral retinal defocus. Based on multispectral refraction topography, peripheral retinal defocus values were categorized as crater type, hemilateral upturn type, saddle type, and relatively flat type. The distribution of different refractive states was analyzed. Results: The spherical equivalent of the 500 participants was(-1.51±2.61) D, axial length was (24.10±1.28) mm, and average corneal curvature was (43.20±1.22) D. Among the 500 eyes, 382 exhibited hyperopic peripheral retinal defocus values, with 316 eyes (82.72%) being myopic. Myopic peripheral retinal defocus values were observed in 118 eyes, with 15 eyes (12.72%) being myopic. Among different types of peripheral retinal defocus values, 112 eyes (22.4%) exhibited a crater type, 153 eyes (30.6%) exhibited a hemilateral upturn type, 107 eyes (21.4%) exhibited a saddle type, and 128 eyes (25.6%) exhibited a flat type. The proportion of myopia was 82.14% (92 eyes), 69.28% (106 eyes), 60.75% (65 eyes), and 3.90% (5 eyes), respectively. The peripheral retinal defocus values at 15°, 30°, and 45° were (0.01±0.08) D, (0.06±0.21) D, and (0.20±0.37) D, respectively. The peripheral retinal defocus values at temporal, inferior, nasal, and superior locations were (0.58±0.69) D, (0.52±0.63) D, (0.21±0.64) D, and (-0.26±0.67) D, respectively. Notably, the superior primarily manifested as myopic, while the others were predominantly hyperopic. Conclusions: Approximately three-fourths of children and adolescents exhibit hyperopic peripheral retinal defocus values, with a higher prevalence of myopia in this subgroup. The hyperopia peripheral retinal defocus value increases with the distance from the retina to the macula. The peripheral retinal defocus values between superior and inferior, nasal and temporal locations are asymmetrical, with the temporal hyperopic peripheral retinal defocus value being most prominent and the superior myopic peripheral retinal defocus value being most evident.

Prevalence and risk factors for astigmatism in 7 to 19-year-old students in Xinjiang, China: a cross-sectional study.

BACKGROUND: To investigate the prevalence and risk factors for astigmatism in 7-19-year-old students in Xinjiang, China. METHODS: A school-based, cross-sectional study was conducted on students who underwent refraction examination in Xinjiang, China, between May and December 2019. The prevalence of astigmatism was determined. Astigmatism was defined as cylinder power (C) ≤-0.75 D, undefined astigmatism as ≤-1.50 D, and high astigmatism as C ≤-3.00 D. Astigmatism types were: against-the-rule astigmatism (maximum refraction of the main meridian in 180° ± 30°), with-the-rule astigmatism (maximum refraction of the main meridian at 90°±30°), and oblique astigmatism (all other cases). RESULTS: Of the 71,838 students examined (51.0% boys, 7 - 19 years old), 25,945 (36.1%, 95%CI: 35.52-36.68%) had astigmatism and 1267 (1.8%, 95%CI: 1.07-2.53%) had high astigmatism. The prevalence of astigmatism was greater in Han individuals (39.6%) compared with the Hui (34.0%), Kazakh (34.0%), Kyrgyz (32.1%), and Uyghur (26.4%) populations. Among the 25,945 students with astigmatism, 19,947 had with-the-rule astigmatism (76.9%), 3405 had against-the-rule astigmatism (13.1%), and 2593 had oblique astigmatism (10.0%). Multivariable logistic regression analysis showed that ethnicity (Han individuals more susceptible), male gender, age, and refractive errors (myopia and hyperopia) were independently associated with astigmatism, high astigmatism, and with-the-rule astigmatism (all P < 0.05). CONCLUSIONS: The prevalence of astigmatism among children and adolescents in Xinjiang was 36.1%, including 1.8% of high astigmatism. In this population, astigmatism was mainly of the with-the-rule astigmatism type (76.9%). Han ethnicity, male gender, and myopia or hyperopia were independently associated with a high risk of astigmatism.

The Relationship between Myopia and Obesity in Adults.

PURPOSE: To investigate the relationship between myopia and obesity through direct measurements of fat content. METHODS: A cross-sectional study used a stratified, multistage survey, the Korea National Health and Nutrition Examination Survey (2008-2010). Subjects 19 years or older (n = 10,305) were included. Participants were divided into three groups according to refractive status: myopia (spherical equivalent [SE] ≤ -1.0 diopter [D]), emmetropia (-1.0 D < SE ≤ 1.0 D), and hyperopia (SE > 1.0 D). Obesity was investigated with assessment of fat mass and body mass index or waist circumference. Fat mass was measured with whole-body dual energy x-ray absorptiometry. Body fat percentage was calculated as (total fat mass / body weight × 100). RESULTS: Higher obesity index was found in individuals with myopic eyes after adjustment for age, sex, education level, income status, physical activity, residence, and serum vitamin D level. The significant difference in total body fat percentages among myopia, emmetropia, and hyperopia was significant in the young age group (19-39 years, p < 0.05) but not in the middle age group (40-64 years) and the old age group (≥65 years). Individuals with a higher percentage of total body fat had greater odds ratios for myopia (fourth quartile of body fat; odds ratio, 1.352; 95% confidence interval, 1.178-1.551). CONCLUSIONS: An association was found between adiposity and myopia in relatively young adults using direct measurements of fat mass.

Detection of significant vision conditions in children using QuickSee wavefront autorefractor.

PURPOSE: This study evaluated the ability of QuickSee to detect children at risk for significant vision conditions (significant refractive error [RE], amblyopia and strabismus). METHODS: Non-cycloplegic refraction (using QuickSee without and with +2 dioptre (D) fogging lenses) and unaided binocular near visual acuity (VA) were measured in 4- to 12-year-old children. Eye examination findings (VA, cover testing and cycloplegic retinoscopy) were used to determine the presence of vision conditions. QuickSee performance was summarised by area under the receiver operating characteristic curve (AUC), sensitivity and specificity for various levels of RE. QuickSee referral criteria for each vision condition were chosen to maximise sensitivity at a specificity of approximately 85%-90%. Sensitivity and specificity to detect vision conditions were calculated using multiple criteria. Logistic regression was used to evaluate the benefit of adding near VA (6/12 or worse) for detecting hyperopia. A paired t-test compared QuickSee without and with fogging lenses. RESULTS: The mean age was 8.2 (±2.5) years (n = 174). RE ranged up to 9.25 D myopia, 8 D hyperopia, 5.25 D astigmatism and 3.5 D anisometropia. The testability of the QuickSee was 94.3%. AUC was ≥0.92 (excellent) for each level of RE. For the detection of any RE, sensitivity and specificity were 84.2% and 87.3%, respectively, using modified Orinda criteria and 94.5% and 78.2%, respectively, using the American Academy for Pediatric Ophthalmology and Strabismus (AAPOS) guidelines. For the detection of any significant vision condition, the sensitivity and specificity of QuickSee were 81.1% and 87.9%, respectively, using modified Orinda criteria and 93% and 78.6%, respectively, using AAPOS criteria. There was no significant benefit of adding near VA to QuickSee for the detection of hyperopia ≥+2.00 (p = 0.34). There was no significant difference between QuickSee measurements of hyperopic refractive error with and without fogging lenses (difference = -0.09 D; p = 0.51). CONCLUSIONS: QuickSee had high discriminatory power for detecting children with hyperopia, myopia, astigmatism, anisometropia, any significant refractive error or any significant vision condition.

Assessment of the effects of myopic and hyperopic anisometropia on choroidal vascular structure in children using SS-OCTA.

OBJECTIVE: To compare large- and medium-sized choroidal vascularity and the choriocapillaris (CC) flow area in children with different refractive errors using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: Forty-two anisometropic children were enrolled and divided into hyperopic anisometropia (HA) and myopic anisometropia (MA) groups. SS-OCTA was performed to analyse choroidal vascularity. Mean choroidal thickness (CT), choroidal vascularity volume (CVV), choroidal vascularity index (CVI) and CC flow area were compared between the two eyes. The inter-ocular differences between the two groups were also determined. RESULTS: Mean CT and CVV were highest in eyes with shorter axial lengths in both refractive groups, and the difference between the two eyes was positively correlated with the difference in axial length at the foveal region. Significant differences in the CVI in the MA group were only found in the parafoveal region. Inter-ocular differences in the CC were significantly reduced in eyes with longer axial lengths in the foveal and parafoveal regions of the HA and MA groups, respectively. Comparing inter-ocular differences, CC was significantly greater in the parafoveal region of the MA group than the HA group. CONCLUSIONS: All layers of choroidal vasculature were thinner in eyes with longer axial lengths in all groups. The inter-ocular CC difference was greater in the MA than in the HA group, with similar differences in axial length. This suggests that both medium-to-large choroidal vascular and choroidal capillaries may play a role in myopia development.

Improving the accuracy of the SRK/T formula in Chinese with implanting less than 10 D IOL calculated by the SRK/T formula: the SRK/T-Li formula.

PURPOSE: To explore the accuracy of the improved SRK/T-Li formula in eyes following implantation of intraocular lens (IOL) of less than 10 D as calculated by using the SRK/T formula in Chinese. METHODS: A total of 489 eyes from 489 patients with cataracts were included in this study. These patients were divided into a training set (271 patients) and a testing set (218 patients). The IOL power calculated by using SRK/T was less than 10 D. We evaluated the accuracy of the modified SRK/T-Li formula (P = PSRK/T × 0.8 + 2 (P = implanted IOL power; PSRK/T = IOL power calculated by SRK/T)). We evaluated the mean absolute error (MAE), percentage of prediction error (PE) within ± 0.25, ± 0.50, and ± 1.00 D, and the percentage of postoperative hyperopia. RESULTS: The MAE values in order of lowest to highest were as follows: 0.412 D (SRK/T-Li), 0.414 D (Barrett Universal II, (BUII)), 0.814 D (SRK/T), and 1.039 D (Holladay 1). The percentage of PE within ± 0.25 D, ± 0.50 D, and ± 1.00 D was 38.99%, 69.27% and 92.66% (BUII), 40.83%, 69.27% and 94.04% (SRK/T-Li), 20.64%, 41.28% and 71.56% (SRK/T), and 7.34%, 16.51% and 53.21% (Holladay 1), respectively. SRK/T-Li had the smallest postoperative hyperopic shift. CONCLUSIONS: For Chinese patients with an IOL power of less than 10 D as calculated by using the SRK/T, the SRK/T-Li has good accuracy and is the best choice to reduce postoperative hyperopic shift.

Causal associations of refractive error and early age-related macular degeneration: A Mendelian randomization study.

This study aims to determine the risk associated with early age-related macular degeneration (AMD) due to refractive errors (RE) using an analysis of genome-wide association study (GWAS) data through the two-sample Mendelian randomization approach. Single-nucleotide polymorphisms (SNPs) linked to refractive errors (RE) were obtained from numerous GWAS studies involving individuals of European descent. The data for early AMD was obtained from a diverse, multiethnic GWAS meta-analysis that included 105,248 participants (14,034 cases and 91,214 controls). The primary outcome measure focused on the rise in early AMD risk corresponding to a 1-diopter alteration in spherical power and cylindrical power. In the main Mendelian randomization analysis, inverse-variance weighting (IVW) methods were applied for the evaluation. Mendelian Randomization (MR) study revealed a substantial impact of refractive error (RE) on early AMD risk, with a 1-diopter increase in hypermetropia being related to a 1.16 odds ratio (OR) for a greater risk of early AMD (95% CI, 1.10-1.23; P < 0.01). This conclusion was further supported by four supplementary approaches, namely, Weighted mode, Weighted-median, Simple mode, and MR-Egger. The results suggest a heightened risk of early AMD correlated with hyperopia, necessitating further research to thoroughly elucidate this potential causal relationship.

Prevalence of Keratoconus Based on Scheimpflug Corneal Tomography Metrics in a Pediatric Population From a Chicago-Based School Age Vision Clinic.

PURPOSE: Determine the pediatric prevalence of keratoconus (KC) using Scheimpflug corneal tomography. METHODS: A prospective observational study was done on subjects aged 3 to 18 years at the Princeton Vision Clinic, Chicago, IL. Scheimpflug tomography (Pentacam HR, OCULUS Optikgerate GmbH) scans (Belin/Ambrósio Enhanced Ectasia BAD3) yielded BAD Final D (Final D) and Back Elevation at the Thinnest Point (BETP) measurements. Criteria differentiating non-KC from KC suspects & KC were, Non-KC -Final D <2.00 in both eyes; KC suspect -Final D ≥2.00 and <3.00 in combination with BETP ≥18 µm for myopia and ≥28 µm for hyperopia/mixed astigmatism in at least one eye; and KC -Final D of ≥3.00 with BETP ≥18 µm for myopia or ≥28 µm for hyperopia/mixed astigmatism in at least one eye. Two thousand two hundred and six subjects were recorded, removing duplicate and poor-quality scans leaving 2007 subjects. RESULTS: Of 2007 subjects, six were classified as KC -prevalence of 1:334, three subjects were KC suspects -prevalence of 1:669, and total prevalence of KC suspects and KC was 1:223. CONCLUSION: The prevalence of KC in children is higher than previously reported, emphasizing the importance of sensitive screening for KC at its earliest manifestation as standard in pediatric comprehensive eye examinations.

Subjective versus objective refraction in healthy young adults.

PURPOSE: To evaluate objective and subjective refraction differences in healthy young adults. METHODS: Data concerning candidates for the Israeli Air Force Flight Academy, as well as active air force pilots in all stages of service who underwent a routine health checkup between the years 2018 and 2019 were retrospectively analyzed. Objective refraction measured using a single autorefractometer was compared with subjective refraction measured by an experienced military optometrist during the same visit. The results were converted to power vectors (spherical equivalent [SE], J0, and J45). To interpret astigmatism using power vector values, the cylinder power (Cp) was determined. RESULTS: This study included 1,395 young adult participants. The average age was 22.17 years (range, 17-39, 84.8% males). The average SE was - 0.65 ± 1.19 diopter (D) compared with - 0.71 ± 0.91D in the auto- and subjective refraction, respectively (p = 0.001). Cp was 0.91 ± 0.52D and 0.67 ± 0.40D, respectively (p < 0.001). This difference was more common in older participants (p < 0.001). J0 and J45 value differences were not significant. The absolute SE value of subjective refraction was lower in the myopic (p < 0.001) and hyperopic (p < 0.001) patients. CONCLUSIONS: Young hyperopic participants tended to prefer "less plus" in subjective refraction compared with autorefraction. Young myopic participants tended to prefer "less minus" in subjective refraction compared with autorefraction. All participants, but mainly older participants, preferred slightly "less Cp" than that measured using autorefraction; The astigmatic axis did not differ significantly between the methods.

Using big data to understand interest in myopia.

SIGNIFICANCE: Popularity of publicly searched myopia terminologies is reported, for example, myopia control over myopia management and myopia over nearsighted or shortsighted. Insights are also provided for searches on specific myopia control interventions. The findings offer an evidence-based starting point for public messaging and communications by clinicians, policymakers, and other industry leaders. PURPOSE: Public understanding of myopia can be difficult to ascertain for clinicians. Although small-scale studies provide valuable snapshots of data, findings tend to be population-specific and thus difficult to extrapolate to global audiences. In this study, big data were used to provide a more comprehensive depiction of global market interest in myopia. METHODS: Google Trends data were used to analyze searches relating to myopia between January 2004 and August 2023. Data extracted were related to use of the terms myopia control and myopia management, with further searches executed for common myopia control interventions: orthokeratology, contact lenses, atropine, and glasses. Analysis into the search interest of other refractive error states, hyperopia and astigmatism, was also undertaken along with alternative terms that may be used to describe myopia. Where relevant, search trends were considered worldwide, by country, and over time. RESULTS: Myopia was a more popular search term than common layman alternatives such as nearsighted or shortsighted. Myopia control was found to be more popular than myopia management, and of the specific myopia interventions, atropine was most popular. Compared with astigmatism and hyperopia, relative search volumes were greatest for myopia, on average accounting for approximately 50% of the relative search volume at the country level. CONCLUSIONS: The differences identified in both popularity of myopia-related search terms and specific interventions may provide the basis for improvements in public messaging and facilitate patient-practitioner communication.

Refractive error and vision related quality of life.

BACKGROUND: To investigate and compare the vision-related quality of life (QOL) in different types of refractive error (RE). METHODS: This cross-sectional study was performed on 200 subjects, categorized into four groups of 50 each, consisting of subjects with myopia, hyperopia, astigmatism, and emmetropia, the latter being the control group. The mean age of the participants was 23.88 ± 5.87 (range, 15 to 38: 110 females and 90 males). RE was defined as myopia, spherical equivalent (SE) < -0.25 diopters (D), hyperopia, SE > + 0.25 D, astigmatism, cylinder < -0.25 D, and emmetropia (-0.25 ≤ SE(D) ≤ + 0.25, cylinder ≥ -0.25). Groups are subdivided into very low magnitudes of RE (0.50 and 0.75) and significant RE (1.00 ≤). Vision-related QOL was assessed using the Persian version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25). The NEI-VFQ was scored as visual function and socioemotional scales using Rasch analysis. RESULTS: Corrected myopia, astigmatism, uncorrected myopia, and hyperopia had a lower vision-related QOL than emmetropes. (P < 0.001). Vision-related QOL in myopic subjects was lower than that in astigmatic participants. Very low myopes, who often do not use correction, had a significantly lower QOL than other groups. CONCLUSION: Individuals with refractive errors experience a lower QOL score than those without. Notably, the adverse impact on QOL score is significantly greater in myopic cases, particularly very low myopia, compared to other refractive errors. Therefore, it is strongly recommended not to neglect managing very low myopia since it may improve participants' QOL.

The association between iris color and refractive errors in children.

This study aimed to evaluate the association between iris color and refractive errors in children aged 6-12 years. This cross-sectional study was based on data obtained from the first phase of the Shahroud Schoolchildren Eye Cohort Study. The target population was 6 to12 year-old students living in urban and rural areas. Iris colors were classified by comparing eye colors with close-up images of iris colors. Myopia was defined as a spherical equivalent (SE) ≤ - 0.5 diopter and hyperopia was defined as SE ≥ 2 diopter in cycloplegic refraction. The association of iris color with hyperopia and myopia was investigated by fitting two separate multiple logistic regression models adjusted for place of residence, age, sex, and times for outdoor activity and near work. Among the 5394 participates with the mean age of 9.7 year, the prevalence of myopia and hyperopia was 4.8% and 4.7% respectively. The number and proportion (in parentheses) of amber, light blue, light brown, dark brown, gray, green and hazel iris colors were 19(0.4%), 26(0.5%), 645(12.0%), 4517(83.7%), 4(0.1%), 59(1.1%), and 124(2.3%) respectively. Compared to dark brown, the odds ratios and 95% confidence intervals (in parentheses) of myopia were 4.8(1.2-18.7), 0.8(0.1-5.8), 1.0(0.7-1.5), 0.4(0.1-2.7) and 0.6(0.2-1.8) for amber, light blue, light brown, green and hazel iris colors in multiple logistic regression model. No significant association was observed between iris colors and hyperopia. This study shows that amber iris is significantly associated with higher odds of myopia. These children should be further monitored and examined. More studies with higher sample size in all iris colors are recommended.

Factors Predicting Slow Visual Recovery Following Hyperopic LASIK.

PURPOSE: To identify factors predicting slow visual recovery following hyperopic laser in situ keratomileusis (LASIK). METHODS: The study included consecutive patients who underwent hyperopic LASIK between January 2005 and December 2019 at a single medical center. Patients were divided into two groups according to whether they experienced normal recovery of visual acuity (1-week visit) or slow visual recovery (1-month visit). Visual recovery was defined as achieving an efficacy index of 0.9 or greater. Efficacy index was calculated as postoperative uncorrected distance visual acuity / preoperative corrected distance visual acuity. A comparison of baseline and intraoperative parameters was performed. Binary logistic regression was performed to identify potential predictors of slow visual recovery. RESULTS: Overall, 861 eyes of 861 patients were included. Mean age was 48.0 ± 9.5 years and 55.9% were women. Two hundred forty-nine patients (28.9%) experienced slow visual recovery. Younger age (P = .01), a larger preoperative spherical equivalence (P = .002), and greater maximum ablation depth (P = .002) were predictors of slow visual recovery. In binary logistic regression, female gender (P = .036) and greater spherical equivalence (P = .007) remained significant predictors of slow visual recovery. CONCLUSIONS: Female gender and greater preoperative spherical equivalence were associated with slow visual recovery. Patients may be advised accordingly. [J Refract Surg. 2024;40(1):e42-e47.].

Factors Predicting Slow Visual Recovery Following Hyperopic LASIK.

PURPOSE: To identify factors predicting slow visual recovery following hyperopic laser in situ keratomileusis (LASIK). METHODS: The study included consecutive patients who underwent hyperopic LASIK between January 2005 and December 2019 at a single medical center. Patients were divided into two groups according to whether they experienced normal recovery of visual acuity (1-week visit) or slow visual recovery (1-month visit). Visual recovery was defined as achieving an efficacy index of 0.9 or greater. Efficacy index was calculated as postoperative uncorrected distance visual acuity / preoperative corrected distance visual acuity. A comparison of baseline and intraoperative parameters was performed. Binary logistic regression was performed to identify potential predictors of slow visual recovery. RESULTS: Overall, 861 eyes of 861 patients were included. Mean age was 48.0 ± 9.5 years and 55.9% were women. Two hundred forty-nine patients (28.9%) experienced slow visual recovery. Younger age (P = .01), a larger preoperative spherical equivalence (P = .002), and greater maximum ablation depth (P = .002) were predictors of slow visual recovery. In binary logistic regression, female gender (P = .036) and greater spherical equivalence (P = .007) remained significant predictors of slow visual recovery. CONCLUSIONS: Female gender and greater preoperative spherical equivalence were associated with slow visual recovery. Patients may be advised accordingly. [J Refract Surg. 2024;40(1):e42-e47.].