Refractive Errors

This is a single-center, randomized, double-blind, controlled study to test whether a new type of eyeglass lens - a "dual-action" lens that combines two technologies (multiple defocus zones and dot diffusion) - can slow the progression of nearsightedness (myopia) in children and teenagers. About the participants: Children and adolescents with myopia who meet the study requirements will be randomly assigned (like flipping a coin) to one of two groups. One group will wear the new dual-action lenses, and the other group will wear Stellest lenses, an established myopia-control lens. Neither the participants, their families, nor the eye doctors doing the follow-up exams will know which lens each child is wearing. About the study: Participants wear their assigned glasses at least 12 hours every day for 12 months and visit the clinic about every 3 months (5 visits in total). At each visit, doctors check eyesight, measure the length of the eyeball, and perform other eye exams. The main goal is to compare how much myopia progresses in the two groups after 12 months, measured by a painless dilated-eye (cycloplegic) refraction test. The study also tracks how comfortable and acceptable the lenses are, and how long children actually wear them each day. Why this research matters: Myopia in children is increasing worldwide, and effective ways to slow it down are still limited. This study will show whether combining two proven optical technologies in one lens works as well as existing options and is safe and comfortable for daily wear.

This study presents a machine learning model that predicts cycloplegic refraction in adults with myopia using standard non-cycloplegic eye measurements, aiming to reduce the need for cycloplegic drops while still identifying patients who require them.

This study aims to evaluate the SmartEyes smart refraction measurement device in two phases under real outpatient optometry room visits at Wuhan Children's Hospital. The first phase used a prospective, single-center, stratified paired cross-sectional clinical validation design, evaluating the consistency between SmartEyes, Topcon KR-800, and subjective refraction/post-dilation refraction results among outpatient children and adolescents without and those requiring dilation, and evaluating the repeatability of the three devices under corresponding conditions. The second phase added prospective cohort follow-up to explore the relationship between SmartEyes fine scale refractive data and axial length growth, evaluating whether these results better match or predict short-term axial growth trends than traditional 0.25D stepped objective refraction results.

After cataract surgery, the thin natural membrane that holds the artificial lens in place can slowly turn cloudy. This is called posterior capsule opacification. It makes vision blurry and can cause glare. The standard treatment is a short, painless laser procedure called Nd:YAG capsulotomy, which opens a small clear window in the cloudy membrane. Opening this membrane changes the support structure around the artificial lens. Eye doctors do not agree on what happens next. Some studies found that the lens shifts slightly backward in the eye after the laser treatment, some found that it shifts forward, and some found no movement at all. It is also unclear whether such a small shift changes how well a person sees or the strength of their glasses. One reason for these mixed results may be that each study used a different imaging device, and these devices measure the depth of the front chamber of the eye in different ways. This study measures the position of the artificial lens in the same eye with three different imaging devices, before and after the laser treatment. The devices are called IOLMaster 700, CASIA2, and Pentacam AXL. All three take detailed pictures of the front of the eye without touching it. The study team wants to find out whether the artificial lens moves after the laser treatment, how much it moves, whether any movement changes vision or the glasses prescription, and whether the three devices give matching results. Who can take part People who had cataract surgery at least three months ago, who now have a cloudy membrane behind the artificial lens, and whose eye doctor has already decided that the laser treatment is needed. What taking part involves Taking part does not change the laser treatment in any way. The decision to perform the treatment, the technique, and the laser settings are made by the treating doctor for medical reasons and are not influenced by the study. The study only adds extra measurements before and after the treatment. There are three study visits: * Visit 1, on the day of the laser treatment and before the laser is used. The extra measurements take about 30 to 45 minutes. * Visit 2, about one week after the treatment. The extra measurements take about 15 to 20 minutes. * Visit 3, about one month after the treatment. The extra measurements take about 30 to 45 minutes. At each visit the study team checks how well you can see, measures the strength of glasses that gives you the sharpest vision, examines your eye with a slit lamp, measures the pressure inside your eye, and takes images with the imaging devices. All of these are standard eye examinations used in everyday clinical practice. Nothing is inserted into the eye, and there are no injections, no medicines, and no radiation. Drops to widen the pupil are not needed for the study. Taking part is voluntary. You can stop at any time, without giving a reason and without any disadvantage for your medical care. Your laser treatment and all routine follow-up visits go ahead either way. There is no payment for taking part, and taking part brings no direct medical benefit. However, the detailed examination may reveal something that would not be noticed during routine follow-up, such as raised eye pressure. If this happens, you will be told and any necessary care will be arranged as part of your normal treatment at no extra cost. Study data are stored under a study code instead of your name.

Corrective eye surgeries, such as Lasik, are widely used to correct focusing problems such as myopia, or nearsightedness. Often these patients develop other conditions like myopic maculopathy or glaucoma which require monitoring with optical coherence tomography (OCT). Since OCT is a light-based test and changes the refractive status of the eye (in the cornea or the lens), it can potentially affect the results of the OCT measurements but has not been sufficiently studied. This pilot study aims at studying the potential change in OCT parameters in the eye after undergoing such surgery.

This is a prospective, school-based randomized controlled trial designed to evaluate auricular acupressure combined with defocus spectacle lenses for myopia control in primary school students with premyopia or myopia. Enrolled students in grades 1 to 4 will be randomly assigned to either defocus spectacle lenses combined with auricular acupressure or defocus spectacle lenses alone. Outcomes will include changes in axial length and cycloplegic spherical equivalent refraction, adherence to the assigned intervention, and safety outcomes over 12 months.

This is a prospective, school-based randomized controlled trial designed to evaluate a wearable device-supported outdoor activity program for myopia prevention in primary school students with adequate hyperopic reserve. Enrolled students in grades 1 to 4 will be randomly assigned to either a wearable device-supported outdoor activity program plus routine school-based eye health education or routine school-based eye health education alone. Outcomes will include changes in axial length and cycloplegic spherical equivalent refraction, incident myopia, intervention adherence, and safety outcomes over 12 months.

This is a prospective, school-based randomized controlled trial designed to evaluate auricular acupressure for myopia prevention in non-myopic primary school students with insufficient hyperopic reserve. Enrolled students in grades 1 to 4 will be randomly assigned to either an auricular acupressure intervention or usual daily activities without additional study-related myopia prevention intervention. Outcomes will include changes in axial length and cycloplegic spherical equivalent refraction, incident myopia, intervention adherence, and safety outcomes over 12 months.

Refractive error is a common visual disorder encompassing myopia, hyperopia, astigmatism and other subtypes. Refractive error in preschool children refers to refractive abnormalities occurring during the preschool period (0-6 years old). Studies conducted across diverse regions and populations report that the prevalence of refractive error among preschool children ranges approximately from 10% to 30%, with this proportion showing a gradual upward trend in recent years. Existing evidence suggests that preschool refractive status is correlated with multiple ocular and systemic diseases. Furthermore, the preschool years represent a highly sensitive window for children's visual development; uncorrected refractive errors at this stage can disrupt visual maturation and induce permanent visual impairment. Accordingly, identifying the full spectrum of comorbidities associated with preschool refractive error, alongside implementing early diagnosis and intervention, is clinically critical. Nevertheless, substantial challenges persist in the clinical management of preschool refractive errors: the complete comorbidity spectrum remains undefined, its natural history has not been fully elucidated, and high-quality evidence-based guidelines for refractive correction and visual rehabilitation are lacking. Establishing a prospective cohort of preschool children with refractive errors is therefore of great significance for clarifying disease progression and risk factors, generating evidence for standardized refractive interventions and visual rehabilitation protocols, and ultimately preventing visual impairment and improving quality of life in this vulnerable pediatric population. Our research team has previously completed preliminary investigations characterizing myopia in preschoolers. Building on this foundational work, we aim to construct a dedicated cohort of preschool children with refractive errors to delineate the natural history, progression risks and comorbidity profiles of preschool refractive error, and explore effective refractive correction and visual rehabilitation approaches for affected young children.

The goal of this research is to develop measurement tools and simulation technology for characterizing and predicting individual responses to corneal treatments and for advancing understanding of corneal ectasia risk factors. Patients who either 1) have keratoconus and are being evaluated for corneal crosslinking or 2) have refractive error and are being evaluated for refractive surgery procedures such as LASIK will have their eyes imaged to assess their mechanical properties and will have computational simulations performed to predict the response to treatment. One aim of the study is to test the hypothesis that computational models can predict the cornea's shape changes within clinically acceptable limits of error.

This operational research project aims to strengthen continuity of eye care delivery between community screening and hospital-based treatment in rural Assam by redesigning referral pathways from the Boko Eye Care Center (ECC) to Sri Sankaradeva Nethralaya (SSDN) base hospital. Despite active outreach in the Boko region from the Boko ECC through conducting regular outreach screenings, less than 30 percent of patients referred to the base hospital actually arrive for evaluation and less than 25 percent of those advised for surgery proceed to treatment. The proposed study addresses these gaps by examining behavioural, structural and logistical barriers to referral completion and surgical uptake, and by implementing a coordinated patient-centered referral and engagement strategy. The proposed intervention comprises of five sequential components: (1) root cause analysis to identify bottlenecks and facilitators in the current referral pathway, (2) community engagement activities to improve awareness and proactive health-seeking behaviour, (3) implementation of an integrated referral and engagement model supported by trained community team and structured referral tracking, (4) strengthening referral completion through patient navigation, scheduled transport and follow-up reminders, and (5) enhancement of surgical acceptance through standardized counseling, affordability support and social reinforcement. The outcomes will be measured prospectively, focusing on increase in hospital footfall from the Boko catchment area, proportion of referred patients who complete hospital visits, and proportion of patients who were advised for surgery and had undergone the procedure. The proposed project aims to achieve a minimum of 70 percent referral completion and 45 percent surgical conversion by the end of the 36-month study period.

To assess subjective visual symptoms using the QoV questionnaire, measure pupil size using the Atongmu Pupillometer, measure wavefront aberrations using the OPD-Scan III Aberrometer, and measure/calculate the effective optical zone using the Pentacam system. The relationships between pupil size, higher-order aberrations (HOAs), effective optical zone after refractive surgery, and subjective visual symptoms will be explored.

The investigators aim to conduct a mixed-method study in which a randomised controlled trial (RCT) and a descriptive qualitative study will be conducted. The RCT aims to determine whether free near and distance glasses provided to residents in Hyderabad, India, aged ≥ 60 years, with under- or un- corrected refractive error and normal baseline hearing and cognition (HMSE \> 18), can improve quality of life, reduce falls, reduce depression, improve social interaction and physical activity cost-effectively over 36 months. The primary qualitative research aim is to a) contextualize the RCT with information on the milieu and culture in which the trial will be conducted; b) provide data on the lived experiences of older adults with reduced vision in the study area, and c) conduct a process evaluation of the trial. The primary outcome measure is the three-year change in cognition measured by LASI- DAD (Longitudinal Aging Study in India(LASI)- Diagnostic Assessment of Dementia(DAD) global cognitive score. Secondary Outcome Measures: Three year change in Quality of Life score measured by WHO QOL-BREF; Visual functioning from the RASCH-scaled version of INDVFQ(Indian Visual Functioning(INDVFQ);self-reported physical activity score measured using IPAQ questionnaire; PHQ9 score; domain specific cognitive score (orientation, executive function, language/fluency, memory) measured by HMSE; Total cost of care including direct and indirect costs; Quality adjusted life years; Incremental Cost Effectiveness Ratio; Number of falls measured by Quick Screen score over the three years; Social network density at 3 years (SNI 1-3 represents a "limited" social network, 4-5 is a "medium" social network, and SNI ≥6 is a "diverse" social network) measured by the SNI score; An additional secondary outcome will be LASI-DAD global cognitive score analysed by excluding any tests determined pre-hoc to depend on visual acuity.

The goal of this observational study is to learn more about the relationship between the size and shape of the eye and the shape of the face in healthy young adults. In particular, the study focuses on whether specific eye measurements are linked to certain facial characteristics after growth and development have been completed. The main question it aims to answer is: Does the size and internal structure of the eye relate to the three-dimensional shape of the face in young adults aged 21 to 25, and are these relationships different in people who are nearsighted (myopic), farsighted (hyperopic), or have normal vision (emmetropic)? Refractive errors such as nearsightedness and farsightedness are very common and are largely influenced by the length of the eye (axial length) and other internal eye measurements. During childhood and adolescence, it develops at the same time as the eye socket (orbit) and the bones of the face. However, most previous studies have examined either the eye or the bony orbit separately. Very few have combined detailed eye measurements with modern three-dimensional (3D) facial measurements in the same individuals. This study will include 120 healthy young adults between 21 and 25 years of age, after facial growth is complete. Participants will be divided into three groups based on their refractive status: myopic (nearsighted), emmetropic (normal vision), and hyperopic (farsighted), with similar numbers of men and women in each group. All participants will undergo a standard ophthalmologic examination. This will include measurement of visual acuity, refraction (to determine glasses prescription), and detailed eye biometry using a non-contact optical device (IOLMaster 700). The measurements will include axial length (eye length), corneal curvature, anterior chamber depth, lens thickness, and corneal diameter (white-to-white). These are routine, non-invasive measurements commonly used in clinical eye care. In addition, participants will undergo non-invasive 3D facial imaging. A short video of the face will be recorded while a camera moves around the participant. Using photogrammetry software, this video will be converted into a precise 3D model of the face. From this model, specific facial landmarks will be identified, and distances and proportions of different facial regions (upper, middle, and lower thirds of the face; cheek width; jaw width; chin projection) will be measured. This method does not involve radiation and does not cause discomfort. The researchers will then analyze whether there are statistical relationships between eye measurements and facial dimensions. They will also compare the three refractive groups to determine whether certain facial patterns are more common in myopic, emmetropic, or hyperopic individuals. Participation is voluntary. All participants will sign informed consent before enrollment. The study has been approved by relevant ethics committees and will be conducted according to international ethical standards. All data will be anonymized and stored securely. No additional risks are expected beyond those associated with a routine eye examination. The results of this study may improve understanding of how eye growth and facial development are related. In the long term, this could contribute to better knowledge of the anatomical background of refractive errors and support future interdisciplinary research in ophthalmology, orthodontics, and craniofacial medicine.

The objective of the clinical investigation presented to is to verify predictions of post-operative PTK-PRK refractive outcome made by the EpiMaster application software by comparing these to post-operative clinical data after routine PTK-PRK treatments.

To establish the baseline levels and monitor the progress of two newly introduced global eye health indicators in Xinxing County, including effective refractive error coverage (eREC) and effective cataract surgery coverage (eCSC). And to assess the prevalence and treatment status of common eye disease in Xinxing County.

The goal of this observational methodological study is to validate the Turkish version of the DDIVAT visual acuity measuring device in a Turkish-speaking adult population. The main questions it aims to answer are: Does the Turkish version of the DDIVAT provide reliable and valid visual acuity measurements in Turkish speakers? Are the results of the DDIVAT comparable to those obtained with the standard Snellen chart used in clinical practice? Researchers will compare DDIVAT visual acuity test results with Snellen chart results to see if both methods produce consistent measurements. Participants will: Be adults aged 18 years or older, including both patients and healthy volunteers. Undergo visual acuity testing using the DDIVAT system displayed on a smart TV connected to the university server. Have their visual acuity re-measured using the standard Snellen optotype under the same conditions. No medication or invasive procedure will be used. The study carries no risk to participants.

To evaluate the optic disc parameters, thickness of ganglion cell complex (GCC), and thickness of peripapillary retinal nerve fiber layer (RNFL) in myopic and hyperopic and emmetrop patients using optical coherence tomography (OCT), and to correlate these changes with axial length and degree of refractive error.

This prospective, school-based cohort study aims to enroll approximately 15,000 primary school students from multiple districts in Shanghai, China and to observe the outcomes on myopia prevention and control in children with varying refractive status (including sufficient hyperopia reserve, relative insufficiency in hyperopia reserve, pre-myopia and myopia) who are exposed to a school-based categorized and integrated interventions strategy in real-world settings. The primary objective of this study is to observe the change in the incidence and prevalence of myopia as well as the the progression of myopia among primary school students population under a school-based interventions, including increasing outdoor activities and wearing special designed optical lenses. The second objective is to identify factors influencing the outcomes and assess the compliance of different intervention methods. Additionally, a cost-effectiveness analysis will be conducted to assess the implementation process, providing technical solutions and operational models for wider application.

The purpose of this clinical investigation is to evaluate the clinical utility of a multifunctional measuring device for Ophtalmology. The results of this clinical investigation will be used to refine and validate the device design. 378 participants total will be included in the trial, each having only one visit at the investigation center.

This is a 12-month longitudinal randomized controlled trial aiming to evaluate the effect of colour temperature of reading lamp on refractive error development.