Clinical Research Directory

Treatment of Residual Hypermetropic Refraction on Young Patients After LASIK Using Human Fresh Corneal Lenticule Implantation With ReLEX Smile Surgery

LASIK (laser-assisted in situ keratomileusis) is a type of refractive surgery for correction of myopia, hyperopia and astigmatism. Yet approximately 30% of operated patients have symptoms like glare, halos, dry eyes and especially residual hypermetrop refractive errors. Residual hypermetrop refractive errors are difficult to treat surgically, the current treatment is Refractive Lens Implantation - risks are similar to those of cataract surgery (endophthalmitis, loss of accommodation, etc.)

ML Models Predicting Cycloplegic Refractive Error Based on Non-Cycloplegic Parameters in Myopic Adults

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.

Correcting Myopia Among Secondary School Children to Increase Academic High School Attendance Rates in Rural Communities

Chinese children are some of the most short-sighted in the world, but only one in five children in poor areas who needs glasses has them. Our team has already shown in other trials that giving children free glasses leads to better grades and that free glasses have a bigger impact on grades than factors like parents' education level and the amount of money a family has. The effect on grades from glasses is greater than from other health services in school, like giving vitamins. Only about one in three children in rural China goes on to a regular, non-vocational high school. The investigators would like to show the Chinese government strong evidence of what glasses can do to help children continue their education, in order to help convince the government to carry out national programs to provide free glasses for children who need them. Study Plan: The investigators will choose 111 middle schools at random in Liaoning, northern China, and all children in Year 1 at each school will go at random into one of two groups: either a group getting free glasses, with support from teachers to push them to wear the glasses ("Intervention") or a group getting just glasses prescriptions ("Control.") The main study outcome will be the proportion of children going on to academic (as opposed to vocational) high school, and the study is powered to detect a 10% difference in this figure between groups.The study will also assess whether children wear their glasses at school and how often they use blackboards (which disadvantage short-sighted children) vs textbooks to learn from. These other outcomes will help us to better understand the causal pathway between vision and high school attendance. We will also study the total cost of providing glasses and the teacher support to wear them per additional student attending academic high school, as well as student mental health outcomes. We will also collect data on the progression of nearsightedness. The hypothesis of this study is that providing glasses will increase academic high school attendance.

Clinical Validation Study Protocol for SmartEyes Smart Optometry Measurement Device (Medical Device Clinical Validation Study)

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.

IOL Position and Refractive Change After Nd:YAG Laser Posterior Capsulotomy

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.

To Study the Effects of Refractive Surgery on OCT Measurements in the Eye

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.

Clinical Investigation of a Femtosecond Laser for Corneal Flap Creation

The purpose of this study is to see how safe the WaveLight Ultraviolet Femtosecond Laser, Model 1026 (UV fs-Laser), is for creating corneal flaps during laser-assisted in situ keratomileusis (LASIK) surgery. This study will be conducted in Australia.

Evaluation of Progression of Myopia in Children Treated With Vitamin B2 and Outdoor Sunlight Exposure

The investigators plan on using riboflavin (a Vitamin that can easily be taken orally each day) and having the children involved in the study play outside (where there is UV light created by the sun) in order to prevent the eye from becoming progressively more near-sighted.

School-based Myopia Prevention Trial for Children With Adequate Hyperopic Reserve

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.

School-based Myopia Prevention Trial for Children With Insufficient Hyperopic Reserve

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.

School-based Myopia Control Trial for Children With Premyopia or Myopia

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.

Cohort Study on Refractive Errors in Preschool Children

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.

VisionApp - Refraction and Presbyopia

Recent Android mobile device technology is available which allows user-measured refractive error and reading add power. This technology could be quite useful to the clinical and research community. The current study aims to evaluate the accuracy, repeatability, and reproducibility of one such technology by VisionApp, specifically with regard to refraction and presbyopia. VisionApp is an app which runs on a smartphone or other device which uses the distance between the user's face and the phone to determine refractive error, while the user looks at different targets (lines, letters, words, etc).

Corneal Elastography and Patient Specific Modeling

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.

Eye Health Intervention Study in Upper Manhattan

Individuals living in Upper Manhattan have limited access to eye care, high vision impairment rates, and poor ocular health outcomes. To improve eye care and vision health outcomes, the Eye Health Intervention Study in Upper Manhattan (EYES-UM) will conduct eye health screenings in accessible primary care health centers and senior centers and implement a behavioral intervention to improve adherence for those referred for in-office eye care. The proposed innovative, 2:1 cluster-randomized clinical trial, will recruit adults age 40 and older in Upper Manhattan with known rates of inadequate eye care. A total of 10 settings in Upper Manhattan, comprised of primary care offices, senior centers, and organizations, confirms access to 17,000 individuals living at or below the NYC.gov poverty measure. This study will conduct ocular tests (visual acuity, intraocular pressure, fundus images) during screenings. To ensure that all participants receive the basic level of service, all participants who fail the eye health screening will be seen the same day by a study optometrist and eyeglasses will be provided at no charge. Educational workshops and an Advisory Board will support recruitment. Intervention Arm participants will receive ongoing support with scheduling eye exams and transportation by trained Study Coordinators. All participants will be followed prospectively for 2 years. The study is guided by the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) Framework. Conducting Focus Groups with health policy stakeholders ensures iterative input during the study to bridge and translate EYES-UM findings into a Vision Health Policy Roadmap for scalable implementation of vision care delivery models, focusing on adherence.

Performance of Refractometers With Self-adjusting Lenses Compared to Cycloplegia in Children (REFRALENS)

This study aimed to compare refractive measurements using Vision-S™ 700, an immersive and compact phoropter with a tunable-focus lens, and Vision-R™ 800, a phoropter with a tunable-focus lens without immersion, with cycloplegic refraction serving as the gold-standard. This a retrospective study aimed to enroll 41 children, aged 6 to 16 years, who underwent refractive assessments with Vision-S™ 700, Vision-R™ 800, and cycloplegic refraction. The primary objective involves a comparison of the spherical equivalent between both devices and compared to cycloplegic refraction. Secondary outcomes include the analysis of astigmatism components (J0° and J45°) and subgroup analyses in myopic and hyperopic children.

Strengthening Community- to- Hospital Eye Care Pathways From Boko Eye Care Center in Rural Assam

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.

Dilated Versus Non-Dilated Wavefront Corrections for Patients With Down Syndrome

Individuals with Down syndrome (DS) live with visual deficits due, in part, to elevated levels of higher-order optical aberrations (HOA). HOAs are distortions/abnormalities in the structure of the refractive components of the eye (i.e. the cornea and the lens) that, if present, can result in poor quality focus on the retina, thus negatively impacting vision. HOAs in the general population are overall low, and thus not ordinarily considered during the eye examination and determination of refractive correction. However, for some populations, such as individuals with DS, HOAs are elevated, and thus the commonly used clinical techniques to determine refractive corrections may fall short. The most common clinical technique for refractive correction determination is subjective refraction whereby a clinician asks the patient to compare different lens options and select the lens that provides the best visual outcome. Given the cognitive demands of the standard subjective refraction technique, clinicians rely on objective clinical techniques to prescribe optical corrections for individuals with DS. This is problematic, because it may result in errors for eyes with elevated HOA given that these techniques do not include measurement of the HOAs. The proposed research evaluates the use of objective wavefront measurements that quantify the HOAs of the eye as a basis for refractive correction determination for patients with DS. The specific aim is to determine whether dilation of the eyes is needed prior to objective wavefront measurements. Dilation of the eyes increases the ability to measure the optical quality of the eye and paralyzes accommodation (the natural focusing mechanism of the eye), which could be beneficial in determining refractions. However, the use of dilation lengthens the process for determining prescriptions and may be less desirable for patients.

Factors Influencing Subjective Visual Quality in Human Eyes

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.

Morphological Characteristics of the Maxillomandibular Region in a 3D Representation and the Refractive Status of the Eye

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.

Cognitive Level Enhancement Through Vision Exams and Refraction

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.

Clinical Data Collection of Myopic Patients After PTK-PRK With CZM MEL 90 Excimer Laser

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.

Assessing the Turkish DDIVAT for Visual Acuity Measurement

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.

Xinxing Eye Cohort Study

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.