View clinical trials related to Refractive Errors.
Filter by:Anxiety is common among patients undergoing eye surgery, which is typically performed under topical anesthesia while the patient is awake. This can be an unsettling experience for patients, who may worry about being able to keep their eyes still during surgery, cooperate with the surgical team, and remain immobile in an unfamiliar environment. Patients may also experience anxiety due to concerns about surgical pain, possible complications, and the uncertainty of the outcome of the surgery. In this study, the investigators aimed to investigate the correlation between the severity of anxiety symptoms during LASIK, and fixation instability during photo-ablation as plotted by the eye tracker.
Approximately 30 soft toric contact lens adapted subjects will be enrolled in this feasibility, bilateral, randomized, double masked (subject and investigator masked), repeated measures insertion study. All subjects will be seen for a Screening/Dispensing Visit at which informed consent will be obtained and eligibility will be assessed. If subjects satisfy all eligibility criteria and none of the exclusion criteria, subjects will have study lenses inserted in random, successive order according to unique randomization schedules that will be provided to each Investigator.
The primary outcome of this study is to compare cyclopentolate 1% and tropicamide 1% for cycloplegic refractions in pediatric populations with esotropia. This will be a prospective double-blinded randomized clinical trial (RCT), multi-center, with randomized sequencing of cycloplegic agent; each patient received one agent at one visit, and the other agent in the next visit (2 different visits ≥ 1 week apart) within 3 months.
The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 12-15 years with uncorrected refractive error in Sierra Leone. The procedures include baseline questionnaires and educational assessments to collect data on students and schools, and then the provision of free eyeglasses to students who have uncorrected (or undercorrected) refractive error (URE). The questionnaires and student assessments will take 1-2 hours. The duration of the study timeframe is one school year. The end-line questionnaires and student assessments will be administered at the end of the school year.
Small incision lenticule extraction (SMILE) is a refractive intrastromal procedure for myopia and myopic astigmatism correction. Most of the studies evaluating astigmatic correction by SMILE reported astigmatic under-correction, especially in high degrees of astigmatism. This under-correction could be due to: first, the active eye tracker or the iris registration is not yet available to overcome the cyclotorsion that occurred during the treatment with the VisuMax femtosecond laser system (Carl Zeiss Meditec, Jena, Germany) which could be overcome by manual compensation technique, especially in higher degrees of cylinders (> 1.5 diopters (D)). Second, in patients with small lenticule diameters, the more abrupt change in thickness at the edge of the treated area could induce more stromal and epithelial healing in this area. Thus, the astigmatic correction would be less effective with small than large lenticule diameters for similar high preoperative astigmatism. This study assessed the outcome of using a 0.5 millimeter (mm) larger lenticule diameter in the fellow eyes of myopic astigmatic correction SMILE participants. This assessment included the safety and effectiveness indices, the refractive and visual outcomes, the contrast sensitivity, and some morphological outcomes such as corneal curvature and epithelial and corneal thickness.
Experienced soft contact lens wearing subjects will be enrolled in this 1-week, post-market, bilateral, repeated measures, dispensing study. All subjects will be seen for a Screening/Dispensing Visit at which informed consent will be obtained and eligibility will be assessed. If subjects satisfy all eligibility criteria and none of the exclusion criteria, subjects will be fit and dispensed study lenses. If unsuccessful in the dispensed lenses, additional lenses may be trialed. Once vision and lens fit are determined to be acceptable, eligible subjects will wear study lenses in both eyes for at least 8 hours per day (with the exception of the follow-up visits where the lenses should be worn for a minimum of 2 hours), for approximately 1 week (7 days +/-3 days). Measurements will be taken at the insertion visit and at the 7-day follow-up visit.
Determine if Total30 for Astigmatism contact lenses (CLs) provide a comfortable wearing experience all day. CL discomfort affects most CL wearers with discomfort consistently topping the reasons why established CL wearers drop out of CLs. In fact, studies have consistently found that the frequency of CL dropout is around 20% with this dropout frequency staying relatively stable over the past 20 plus years. This static frequency of CL dropout is surprising since there have been a number of dramatic soft CL innovations during this time frame (e.g., widely available daily disposable CLs, silicone hydrogel CL materials with high oxygen transmissibility, new CL surface coatings).
The purpose of this study is to assess the clinical performance of DAILIES TOTAL1® spherical soft contact lenses over approximately 1 week of daily wear.
Demonstrate that refraction measurements from the device agree with refraction measurements from a phoropter within clinically meaningful limits.
The purpose of this study is to assess the WaveLight Ultraviolet Femtosecond Laser System, Model 1026 (UV fs-Laser) corneal flap creation accuracy as compared to the already marketed WaveLight FS200 Infrared Femtosecond Laser, Model 1025 (IR fs-Laser).