Astigmatism

Researchers are evaluating two commercially available trifocal toric intraocular lenses to compare their clinical outcomes and patient satisfaction in people undergoing cataract surgery. The main goal is to compare the distance-corrected intermediate visual acuity provided by these lenses. Additionally, the study aims to assess and compare the safety of the two trifocal toric intraocular lenses designed to correct astigmatism and improve vision at near, intermediate, and distance ranges. Participants will be randomly assigned to receive one of two types of trifocal toric intraocular lenses: Optiflex TRIO or AcrySof IQ PanOptix. Both lenses are single-piece, posterior chamber foldable intraocular lenses with advanced aspheric optics and a trifocal design intended to reduce dependence on glasses. The Optiflex TRIO features a refractive-diffractive trifocal toric optic with a square edge design, while the AcrySof IQ PanOptix has a diffractive trifocal optic with a toric component. Each participant will receive one of these lenses based on randomization during cataract surgery. During the study, participants will be monitored for visual acuity outcomes, focusing on binocular distance-corrected intermediate vision at six months after lens implantation. Researchers will also track patient satisfaction and safety throughout the study period. The study includes preoperative assessments such as corneal topography or keratometry to measure astigmatism and will involve follow-ups to evaluate visual performance and any adverse effects. The total duration of participation varies but includes at least a six-month follow-up for outcome measurement.

This research aims to compare the effectiveness and remaining refractive error of two types of phakic toric intraocular lenses in patients with moderate to high myopia and astigmatism. The study also evaluates and compares the safety of the EYECRYLTM Phakic Toric lens versus the Visian4 Toric Implantable Contact Lens in this patient group. Phakic intraocular lenses are clear lenses surgically placed in the eye without removing the natural lens, helping to improve uncorrected vision by focusing light correctly on the retina. Participants will be randomly assigned to receive one of two treatments: the Eyecryl Phakic Toric intraocular lens or the Visian4 Toric Implantable Contact Lens. Both lenses are designed to correct myopia and astigmatism and are implanted either in the anterior or posterior chamber of the eye. The study involves surgical placement of these lenses to assess their performance and safety over time. During the study, participants will attend all scheduled follow-up visits to monitor visual outcomes and safety. Researchers will measure the mean residual refractive error six months after lens implantation as the primary outcome. Safety assessments and other evaluations will also be conducted to track the lenses' effects. The study started in October 2021 and is expected to continue until February 2027, with ongoing monitoring of participants' vision and eye health.

Researchers are evaluating a new form of LASIK called Ray Tracing Guided LASIK by comparing it to three other types of corneal refractive surgery: KeratoLenticule Extraction (KLEx) using the Zeiss Visumax 800 Laser, Wavefront Optimized LASIK (WFO LASIK) using the Alcon EX500 Laser, and Topography Guided LASIK (Contoura LASIK) also using the Alcon EX500 Laser. The study focuses on patients with myopia or myopia with astigmatism and aims to compare visual outcomes across these different technologies in a prospective, randomized design. This study is conducted in three phases, each including at least 44 participants who undergo surgery for refractive correction. In each phase, patients will have one eye treated with Ray Tracing Guided LASIK and the other eye treated with one of the three comparator procedures. The surgeries use specific laser devices and technologies tailored to each method. Participants will receive routine postoperative care and medications as per standard practices. Participants will attend follow-up visits at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months after surgery. At several visits, including screening and postoperative timepoints, patients will complete questionnaires about their experience. Researchers will measure uncorrected visual acuity at 3, 6, and 12 months as the main outcome. Additional assessments include predictability of vision correction. Retreatments are allowed only after all study visits are completed or the subject has left the study.

Researchers are studying the accuracy of measuring total corneal astigmatism compared to the actual corneal astigmatism under different regional measurement settings. This observational study focuses on patients who have undergone phacoemulsification surgery, with or without the implantation of toric intraocular lenses (IOLs), and have a certain degree of corneal astigmatism. The goal is to find the best region setting for measuring corneal astigmatism accurately. Participants with corneal astigmatism will have various eye measurements taken using specialized devices. These include total corneal astigmatism and anterior chamber depth measured by a Scheimpflug tomographer, pupil size assessed by the itrace and MONCV3 devices, and residual astigmatism evaluated through subjective refraction. The study observes these measurements at least one month after their cataract surgery. During the study, participants will undergo eye exams and tests to collect the necessary data. Researchers will analyze differences in vectorial measurements, pupil sizes, residual astigmatism, and anterior chamber depth to determine measurement accuracy. The study monitors these outcomes to optimize corneal astigmatism measurement methods. Participation duration varies depending on individual schedules and follow-up visits.

Researchers are evaluating a new algorithm-assisted subjective refraction software designed specifically for children aged 6 to 12 years. This study aims to compare the accuracy of two versions of this software, each used with Vision-S™ and Vision-R™ phoropters, against the conventional subjective refraction method performed manually with the Vision-R™ phoropter. The research focuses on improving the standardization and accuracy of refraction assessments in children. The study has two phases: Phase A will validate the first version of the Kids refraction software (vA) and Phase B will evaluate the second version (vB), which includes additional steps to help manage the child's attention and cooperation. Participants will undergo subjective refraction tests using both software versions with Vision-R™ or Vision-S™ devices, as well as conventional subjective refraction with Vision-R™. Measurements will be taken under non-cycloplegic conditions, with some assessments also performed under cycloplegic conditions. Participants will have their visual acuity and refraction results assessed multiple times, including Sphere, Cylinder, and Axis measurements, starting from Day 1 and continuing up to 7.5 months. The study includes comparisons between non-cycloplegic and cycloplegic refraction results using various devices. Researchers will monitor visual acuity throughout the study to evaluate the software's performance. The total duration of participation for each child will be approximately 7.5 months.

Researchers are evaluating self-reported quality of vision and quality of life in physicians and medical students undergoing LASIK, SMILE, and PRK eye surgeries. The study focuses on understanding how these procedures affect vision and daily life over a 12-month period. Participants must meet specific medical and ophthalmic criteria to be considered suitable candidates for these refractive surgeries. Participants will have a thorough eye exam including slit lamp and dilated fundoscopic examinations, as well as computerized videokeratography before enrollment. Those eligible will undergo bilateral simultaneous LASIK, SMILE, or PRK surgery. The Quality of Vision Questionnaire is used to assess outcomes before surgery and at 3 and 12 months post-operation. Standard post-operative care includes topical antibiotics and anti-inflammatory eye drops as appropriate. Participants will attend visits before surgery, on the day of surgery, and at 1 day, 1 month, 3 months, and 12 months afterward, with additional visits as needed. The study measures include self-reported vision quality and quality of life, predictability of vision correction, changes in visual acuity, and contrast sensitivity. Follow-up is conducted under the care of the treating physician to monitor safety and progress for up to one year.

Researchers are evaluating the wearing experience of the A.M.L. series of lenses in children with myopia aged 6 to 12 years. The study aims to find out how quickly and effectively children adapt to these lenses and the proportion who adapt within 4 to 6 days. This research responds to the rising prevalence of myopia in children and focuses on comfort, adaptation, and user satisfaction beyond just vision correction. In this one-arm, interventional study, 40 myopic children will wear the A.M.L. series of lenses continuously for two weeks. Participants will have scheduled visits to assess their adaptation and comfort at day 4 to 6, at one week, and at two weeks. The study focuses solely on this device without a comparison group. During the study, participants will be monitored for adaptation by checking if they experience any symptoms while wearing the lenses. Visual comfort, wearing time, and overall satisfaction will be evaluated using questionnaires at multiple time points. The main outcome is the proportion of children who adapt within 4 to 6 days without symptoms. The total participation lasts two weeks with follow-up visits to track progress and user experience.

This research aims to analyze the factors influencing high-order aberrations following Small Incision Lenticule Extraction (SMILE) surgery, focusing on patients with lenticule retained. High-order aberrations are key indicators used to assess visual quality after refractive surgery. While previous studies have explored complications related to these aberrations, there is limited high-quality research on patients with covert residual lenticule, which complicates clinical decisions about additional surgery. The study compares high-order aberrations between patients with and without peripheral residual lenticule to provide a detailed evaluation of postoperative visual quality. It involves two groups: the lenticule retained group and the non-lenticule retained group. This observational study does not involve treatment interventions but collects data to understand the relationship between residual lenticule and visual outcomes. Participants will be followed up with assessments of higher-order aberrations at 90 days post-surgery. The study includes clinical evaluations and wavefront analysis to measure visual quality objectively. The findings aim to guide improvements in SMILE surgical techniques and postoperative care. The total participation involves initial assessment and follow-up visits as per the study plan.

Researchers are studying the changes in the ocular surface microbiota in patients who have undergone femtosecond laser-assisted in-situ keratomileusis (FS-LASIK) surgery. The study focuses on understanding how these microbiota changes relate to dry eye syndrome (DES) caused by FS-LASIK. By analyzing these changes, new treatment ideas for patients with FS-LASIK induced DES may be developed, and the incidence of this condition might be reduced. The study will include 160 postoperative patients divided into two groups: those with dry eye and those without. Microbial samples from the conjunctival sac will be collected before and after surgery. The ocular surface microbiota changes will be analyzed using 16S rRNA sequencing technology to evaluate their impact on FS-LASIK induced DES. Participants will undergo dry eye examinations, conjunctival sac microbiota sampling, and corneal nerve condition assessments before the surgery and on postoperative day 90. Researchers will track these measurements to understand the relationship between microbiota changes and dry eye development after FS-LASIK. The total participation duration includes preoperative and 90 days postoperative evaluations to monitor outcomes and collect relevant data.

This research aims to improve correction of astigmatism during corneal refractive surgery by using phototherapeutic keratectomy (PTK) mode to precisely mark the axis of astigmatism. Astigmatism correction is challenging because it involves both magnitude and direction, and errors can occur due to head or eye rotation. The study explores using excimer laser therapeutic keratectomy to set laser parameters for accurate axis marking, aided by static cyclotorsion of the eye. Participants will be divided into two groups: one receiving the PTK mode marking procedure (experimental group) and one with no intervention (limbus group). The PTK mode aims to precisely mark the astigmatism axis using laser treatment. The study is non-randomized and open-label, with no masking. No additional treatments or procedures beyond the marking are described. During the study, researchers will measure participants' eye refraction three months after the procedure to assess the accuracy of astigmatism correction. Participants must be at least 18 years old and free of ocular diseases. The trial also allows healthy volunteers. The total duration and follow-up details focus mainly on the primary outcome at three months post-treatment.