Headache disorders and untreated vision problems are both common among adolescents. This study aimed to examine headache characteristics in adolescents and potential associations with untreated vision problems. As part of a school vision testing programme, 230 Norwegian adolescents aged 15.5 ± 0.5 years (mean ± SD) completed a structured questionnaire including questions that allowed for classification according to The International Classification of Headache Disorders, 3rd edition. The Wong-Baker FACES Pain Rating Scale was used for registration of pain intensity. The questionnaire also registered general health, pain/discomfort in the upper body, screen time and physical activity. A total of 190 (83
To compare an objective assessment of intermittent exotropia (IXT) control and deviation size using the binocular eye alignment monitor (BEAM) to standard clinical assessments. IXT control and deviation size were evaluated in 15 participants aged 8–35 years. Participants completed two visits that included a 90-min BEAM eye movement recording at a distance (6 m) to evaluate distance IXT size and control of the deviation objectively. IXT control was assessed using the mean of three measurements of the IXT Office Control Scale, and the deviation size was measured with the prism alternate cover test (PACT). The mean IXT control score in the IXT participants was 2.2 ± 1 points, which was weakly correlated with the percentage of time strabismic as measured by the BEAM (Spearman’s correlation coefficient = 0.29; p = 0.30). Distance PACT and mean BEAM deviation size demonstrated a moderate, non-significant association (ρ = 0.47, p = 0.08). BEAM measurements were consistently smaller than PACT measurements. IXT distance control (0.44; 95
To evaluate 2 year fundus progression and associated factors in adults in the Aier-SERI High Myopia cohort in Changsha, China. A total of 367 adult high myopes (spherical equivalent [SE] ≤ –5.0D) underwent baseline and 2 year assessments, including colour fundus photography graded by the Meta-analysis for Pathologic Myopia (META-PM) classification. Progression was defined as advancement to a higher category, enlargement of atrophy or development/worsening of plus lesions. Associations were analysed using multivariable generalised estimating equation (GEE) logistic regression adjusting for age, sex, SE or axial length (AL) and baseline META-PM category. In this cohort (mean age: 45.2 ± 7.3 years), fundus progression occurred in 31/734 eyes (4.2
To evaluate short-term effects of violet, red and combined violet and red light exposure on axial length, choroidal thickness and vascular perfusion in adults as a step toward understanding acute ocular responses to spectral illumination. Twenty participants (ages 28.2 ± 3.5 years) completed four sessions on separate days of 60 min exposure to either (1) broadband, (2) violet (peak 400 nm), (3) red (peak 628 nm) or (4) combined violet + red light. Biometry (LenStar) and optical coherence tomography and angiography (Spectralis) were performed at baseline, after exposure and after 30 min of recovery. Axial length, choroidal thickness, perfusion density of the superficial and deep vascular complex and choriocapillaris and foveal vascular zone were analysed across time and light conditions. Choroidal thickness decreased significantly over time across lighting conditions (p < 0.001) while no significant main effect of condition (p = 0.27) or condition-by-time interaction (p = 0.44) was observed. Bonferroni-adjusted within-condition comparisons showed significant reductions in choroidal thickness following 60 min of violet (−4 ± 1 µm) and red light exposure (−8 ± 2 µm) relative to baseline (all p ≤ 0.02). No significant changes were observed under broadband or combined violet + red light. Axial length and vascular metrics did not change significantly with time or lighting condition (all p > 0.21). Short-term exposure to narrowband red and violet light was associated with modest reductions in choroidal thickness in young adults; however, changes did not differ significantly across lighting conditions. Combined red and violet light exposure produced no measurable effect. Together, these findings suggest that acute ocular responses to spectral illumination are limited under the conditions tested and do not support distinct wavelength-specific effects in young adults.
To evaluate the precision of pachymetry determined using the MS-39 device across different levels of keratoconus (KC) and to establish thresholds for detecting disease progression. This study examined 27, 29, 34 and 41 eyes with forme fruste keratoconus (FFKC), mild KC, moderate KC and severe KC, respectively. To assess repeatability, single-measurement and three-measurement reproducibility, three consecutive measurements were obtained with the MS-39 by two well-trained operators. The within-subject standard deviation (Sw), test–retest variability (TRT), coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were employed for statistical analysis. The MS-39 demonstrated high repeatability and reproducibility in measuring corneal thickness in KC patients, with all ICC values exceeding 0.90. Based on precision analyses, the following critical values for the thinnest corneal thickness are recommended: for FFKC, mild, moderate and severe KC stages, thresholds should be set at 4.43, 6.58, 8.34 and 16.71 µm, respectively, when using triple-averaged measurements. Conversely, for single measurements, the corresponding thresholds are 6.68, 10.89, 10.20 and 23.31 µm. Exceeding these values should prompt careful re-evaluation of measurement error or progression of the disease. The MS-39 had high repeatability and reproducibility across different levels of KC severity. Given the corneal irregularity in KC, averaging three measurements may improve reliability and reduce errors in clinical decision-making. Moreover, grading KC patients accurately and applying different thresholds is an effective approach.
To characterise comprehensively refractive status, ocular biometry, retinal and choroidal thickness and microvasculature, optical quality and visual activity in young adult students in the United States. First year optometry students (N = 121, age 23.12 ± 1.64 years) underwent cycloplegic autorefraction (Grand Seiko), biometry (LenStar), optical coherence tomography and angiography (Spectralis) and ocular aberrometry (COAS HD). A visual activity questionnaire was administered. Retinal and choroidal thickness and vascular perfusion density were quantified. Ocular data and visual activity were analysed by age and race and compared across refractive error groups. Mean spherical equivalent refraction (SER) was −2.67 ± 3.00 D, with 12
To identify when postoperative cylinder adjustment with a light-adjustable lens (LAL) is expected to reduce residual astigmatism more than a toric intraocular lens (IOL), whose effect depends on axis placement and rotational stability. Power-vector analysis was used to derive a closed-form expected squared residual cylinder for a non-toric IOL, toric IOL and LAL. The toric model included a cylinder-dependent axis-error term and a cylinder-independent RMS floor; the LAL model included a cylinder-independent floor up to a platform-specific deliverable ceiling. Parameters were informed by published biometric, toric-alignment and LAL data. Closed forms were checked by Monte Carlo simulation, with sensitivity analyses across residual floors and axis-error distributions. The toric RMS residual comprised a floor plus a misalignment term that increased with corneal cylinder and combined axis-error variance. The LAL residual remained near its floor within its deliverable range. With floors of 0.30 and 0.29 D for toric and LAL, respectively, the LAL advantage was essentially the toric misalignment penalty. At 2.00 D of cylinder, RMS reduction was 0.17, 0.77 and 1.06 D at alignment standard deviations of 5°, 15° and 20°, respectively. Below about 2 D on a stable platform, the gain was generally smaller than 0.50 D; with high cylinder and high combined alignment uncertainty, it could exceed a 0.50-D cylinder step. The comparison was robust across plausible floors and the non-Gaussian error distributions tested. Above the LAL ceiling, LAL monotherapy leaves residual astigmatism from a cylinder beyond the deliverable range. Postoperative adjustability has the most astigmatic value when cylinder and alignment uncertainty are both high. For routine eyes, lens choice is more likely to be governed by cost, treatment burden and target refraction than by residual cylinder accuracy alone.
This observational follow-up evaluated the long-term efficacy of Defocus Incorporated Multiple Segments (DIMS) spectacle lenses in children over 8 years and identified factors that influence the treatment response, particularly baseline relative peripheral refraction (RPR). Data from an 8-year study of DIMS lens myopia control effectiveness was reviewed retrospectively. Participants were analysed by types of lens wear (DIMS vs. single vision (SV)) and categorised by baseline RPR. Effectiveness was calculated by comparing the 8-year DIMS subgroup against historical controls, with analyses including and excluding participants with myopic RPR. Sixty participants who completed the previous 6-year follow up, attended the 8+ year investigation: 38 and 22 exhibited hyperopic and myopic RPR at baseline, respectively. Among continuous DIMS lens wear (n = 14) for the whole period, the myopic RPR subgroup (n = 4) showed statistically significantly greater axial elongation than the hyperopic RPR subgroup (n = 10) between 6 to 8+ years (mean difference: 0.17 ± 0.06 mm, p = 0.009). Excluding myopic RPR participants, DIMS wearers exhibited a statistically significant reduction in axial elongation compared with SV wearers (mean difference: 0.13 ± 0.05 mm, p = 0.009), though myopia progression did not differ significantly (p = 0.12). Over the full 8+ year period, DIMS wearers with hyperopic RPR (n = 10) achieved a 56
To compare radial and horizontal raster acquisition patterns using spectral-domain optical coherence tomography (OCT) for assessing choroidal vascularity index (CVI) in healthy eyes and to evaluate how variability in chorio-scleral interface (CSI) delineation influences CVI measurements. OCT images of 25 eyes from 25 healthy adults were acquired using 12-line radial and 31-line horizontal raster scans with enhanced depth imaging. CVI was measured manually using three different posterior boundaries—defined as the upper (vascular), middle (vascular–stromal) and lower (stromal) CSI boundaries. Agreement between CSI boundaries and scan patterns was assessed using Bland-Altman analysis. Topographical CVI variations across 6-mm Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields, quadrants and rings were evaluated using two-way repeated-measures ANOVA. Participants were aged 21–31 years (72
The origin of myopia is multifactorial, with nearwork as one possible risk factor. Spectacles with peripheral positive defocus aim to inhibit further ocular elongation. However, myopic eyes of young adults were found to become longer with positive defocus. Additionally, they showed reduced ability to use chromatic cues for detecting the retinal defocus sign. Possible underlying retinal differences to non-myopes are yet to be determined. The ciliary muscle (CM) was imaged in near-emmetropes and myopes (18–30 years of age) using optical coherence tomography after consecutively watching a movie for 30 min (i) in focus and (ii) with +3.00 D lenses, to assess possible interactions of defocus with accommodation. After a 2-h break, long flash electroretinograms (ERG) were measured after clear and defocused viewing. ERG b- and d-waves served as proxies to evaluate retinal ON- and OFF-responses. At a separate visit for a subgroup, the ERG experiment was exploratively repeated under red-light restriction. B-wave amplitudes were reduced (−4.74 µV) and delayed (+0.30 ms, both p < 0.001) in both groups after experiencing defocus. The CM became significantly thinner in myopes only (−19.43 µm, p = 0.007). Exploratory outcomes with red filters revealed smaller b-wave amplitudes with defocus (Δ = −6.44 µV, p = 0.003), as well as delayed b-waves without (Δ = 1.03 ms) and with defocus (Δ = 0.67 ms, both p < 0.001) in both groups. OFF-response proxies of the myopic sub-group showed reduced i-waves after defocus, independent of light conditions. Sustained positive defocus reduced physiological proxies for retinal ON activity irrespective of the refractive error. After defocus exposure, the CM of myopes reacted similarly to after sustained nearwork, as found previously. Altered OFF-response proxies in myopes after blur could point to modified retinal processing. Paediatric trials are required to assess whether these acute physiological responses following fixed-sequence defocus exposure relate to ocular growth signals, myopia progression or optical treatment response.
This study aims to forecast future trends and quantify the contributions of key determinants, extending current evidence for tailored interventions The study used data from the Global Burden of Disease Study 2021 for children, adolescents and young adults aged 0–24 years. Temporal trends were analysed with joinpoint regression, while health inequalities were assessed using the slope index of inequality (SII) and concentration index (CIx). Bayesian age-period-cohort (BAPC) modelling and XGBoost were employed to project prevalence and years lived with disability (YLDs) and SHAP values were used to quantify the contributions of key predictors. A slight but significant global decrease was observed in both prevalence (average annual percent change, AAPC: –0.05
This study aimed to investigate near viewing modifications during smartphone usage between presbyopes and non-presbyopes. A cross-sectional study design was employed, involving corrected presbyopes and non-presbyopes who completed a series of standardised reading tasks on a smartphone under habitual viewing conditions. The time taken to complete each reading task was recorded. Viewing distance and craniovertebral angle were measured from images captured at a distance of 2 metres while participants performed the tasks, allowing for objective assessment of posture and working distance. Corrected presbyopes used significantly larger font sizes to complete the reading tasks compared with non-presbyopes (p < 0.01). They also completed the reading tasks at significantly greater viewing distances (p < 0.001) and required significantly longer completion times (p < 0.001). However, craniovertebral angles did not differ significantly between the two groups during task performance (p > 0.05), suggesting similar neck posture despite differences in visual demand. Despite reading with a significantly larger font size, presbyopes required a longer viewing distance and more time to complete all reading tasks, indicating increased visual effort and adaptation during smartphone use. These findings highlight the additional visual demands experienced by corrected presbyopes during near digital tasks. Therefore, prescribers should consider the specific visual tasks an individual engages in when prescribing presbyopic correction rather than relying solely on the conventional 40 cm near working distance, as real-world smartphone usage may require different accommodative and ergonomic considerations.
To design an extended depth-of-focus (EDoF) intraocular lens (IOL) with a full-aperture aberration-neutral profile and to evaluate its optical stability under decentration and tilt using an anatomically accurate schematic eye model. In this study, ‘additional vision’ refers to the functional intermediate/near vision range provided by the EDoF IOL beyond the distance focus. A new EDoF IOL based on the aberration-neutral technique was designed and optimised within the Navarro–Escudero model eye. Optical performance, including modulation transfer function through-object (MTF-TO), spot diagrams and ray tracing, was simulated under alignment, 0.5 mm decentration and 5° tilt using a numerical simulation method. Results were compared with a commercial monofocal IOL (IOL A) and two commercial EDoF IOLs (IOL B and IOL C) using the Liou–Brennan model eye. Under perfect alignment, the new IOL achieved an MTF of 0.36 at 50 cycles/mm for distance and a continuous MTF-TO response from distance to near, confirming its EDoF functionality. Compared with IOL B and IOL C, the new design provided a wider depth of focus (1.2 D versus 1.1 D and 0.5 D) and a higher additional vision MTF (0.30 versus 0.19 and 0.27) under aligned conditions. Under 0.5 mm decentration, the distance MTF of the new IOL decreased by less than 3
To validate a wrist-worn multimodal wearable system for synchronised monitoring of multispectral light exposure, activity phenotypes and five-stage sleep architecture in children and adolescents in a structured 24-h pilot validation protocol. A wrist-mounted multimodal wearable system was developed, integrating a 9-channel multispectral light sensor (350–1000 nm), a 9-axis inertial measurement unit (IMU) and a photoplethysmography (PPG) sensor for synchronised acquisition of environmental light, body movement and cardiovascular signals. Twelve healthy children and adolescents (mean age: 10.04 ± 3.26 years; range: 6–15 years) underwent a 24-h pilot validation protocol. Long short-term memory (LSTM) networks were developed for activity recognition and a Stacking ensemble framework combined with cost-sensitive learning was implemented for five-stage sleep classification, i.e., wake (W), non-rapid eye movement stage 1 (N1), non-rapid eye movement stage 2 (N2), non-rapid eye movement stage 3 (N3) and rapid eye movement (REM). Under the three lighting conditions tested, the device captured distinct spectral irradiance profiles: outdoor natural light (1.8 W m−2 nm−1; broad-spectrum 350–1000 nm), indoor natural light (0.30 W m−2 nm−1) and artificial illumination (0.07 W m−2 nm−1; peak at 545–600 nm). The LSTM-based model achieved 86.33
While defocus incorporated multiple segments (DIMS) spectacle lenses are clinically proven effective in slowing myopia progression, the long-term, real-world patient experience is poorly understood. This study aimed to provide both quantitative and qualitative analyses of the wearer experience in a long-term cohort of DIMS wearers. This retrospective, convergent parallel mixed-methods study included 63 former child participants (now aged 17–23 years) who participated in the previous DIMS spectacle lenses clinical trial 8–10 years earlier. Data were collected 2 years after the final clinical trial concluded. A quantitative online questionnaire assessed wearer experience, while in-depth, semi-structured phone interviews explored the lived wearer journey. Predictors of satisfaction were identified using multiple linear regression and qualitative transcripts were analysed using a systematic thematic approach. Quantitative analysis revealed high satisfaction, with 88.9
To investigate the effectiveness of spectacle lenses with highly aspherical lenslets (HAL) and orthokeratology (ortho-k) for myopia control and the change in the interocular axial length (AL) difference in binocular anisomyopic children over 1-year in a real-world setting. Retrospective analysis of 74 bilateral anisomyopes (8–14 years; 39 HAL, 35 ortho-k). Axial elongation (AE) and interocular AL difference were compared in both groups; spherical equivalent refraction (SER), spherical refraction (SR), refractive astigmatism (RA) and corneal astigmatism (CA) were evaluated for the HAL group. AE in the more myopic eye (MME) of the HAL group was significantly greater than the ortho-k group (0.24 ± 0.17 vs. 0.15 ± 0.15 mm, p = 0.007). However, the opposite finding was observed in the less myopic eye (LME) (0.20 ± 0.14 vs. 0.29 ± 0.23 mm, p = 0.01). The interocular AL difference was reduced in the ortho-k group (0.69 ± 0.41 vs. 0.54 ± 0.32 mm, p = 0.007), whereas no significant change was found in the HAL group (p = 0.09). AE was associated with baseline SER (β = 0.08, p = 0.008) in the ortho-k group and age (β = −0.04, p = 0.001) in the HAL group. The MME in the HAL group showed larger changes in SER (−0.39 ± 0.31 vs. −0.27 ± 0.30 D) and CA (−0.21 ± 0.29 vs. −0.11 ± 0.25 D) than the LME (both p ≤ 0.03). The change in SER was positively associated with age and baseline SER (β = 0.08; β = 0.07, both p ≤ 0.02) in the HAL group. Ortho-k reduced AE, more so in the MME and reduced the interocular AL asymmetry. HAL slowed AE symmetrically, with greater control in older and less-myopic children.
