View clinical trials related to Astigmatism.
Filter by:The planned clinical investigation will be conducted to acquire raw data for the development of the algorithm. The data acquisition is intended to obtain first impressions of the potential performance of the changed hardware and software components and to confirm the safety profile assessed by risk analysis.
Cataract surgery by phacoemulsification is the most commonly performed procedure in Pakistan. Cataract surgery aims for visual rehabilitation and freedom from all kinds of eyewear. Pre-operative corneal astigmatism greater than 1.0 Diopter is reported in 42% preoperatively and 58%postoperatively after implanting a monofocal intraocular lens(IOL). Visual acuity tended to worsen postoperatively with increased astigmatism4. Different treatment modalities are used to reduce astigmatism, like toric IOL. Limbal relaxing incision, actuate keratotomy, intrastromal rings, Lasik and femtosecond laser. Most of these modalities are expensive, so they cannot be afforded by the patients as Pakistan is a low-income country with a per capita income of US$1,562 (160th worldwide)
Low amounts of postoperative residual astigmatism may worsen the visual performance of patients implanted with presbyopia- correcting intraocular lenses (IOLs). Although extended depth of focus (EDoF) IOLS have introduced optical improvements, it is important to determine the tolerance of these IOLs to postoperative astigmatism. This is important for an appropriate surgical planning. Therefore, the aim of this study is to simulate and assess the impact of mild amounts of residual mixed astigmatisms with the axis oriented in different positions (vertical, oblique and horizontal) in eyes implanted with the Vivity® IOL.
Experienced soft contact lens wearing subjects will be enrolled in this 1-week, confirmatory, randomized, bilateral, 2-way crossover, double masked (subject and investigator), repeated measures, dispensing study. All subjects will be seen for a Screening/Baseline Visit at which informed consent will be obtained and eligibility will be assessed.
Evaluation of the Accuracy and Safety of the LaserArcs Femtosecond Cataract Surgery Arcuate Incision Nomogram in Patients Undergoing Cataract Surgery and Astigmatism Reduction
This will be a multicenter, prospective, open label, non-randomized, single arm 12 month study, evaluating the safety and effectiveness of the TECHNOLAS TENEO 317 Model 2 (Software version "1.28 US") excimer laser when used in LASIK surgery to treat hyperopia with or without hyperopic astigmatism. Both eyes of a subject may be enrolled so long as both eyes meet all inclusion/exclusion requirements. Analysis of the primary effectiveness endpoint will be completed at refractive stability.
Corneal astigmatism is refractive error that impairs uncorrected visual acuity. When patients undergo cataract surgery, implantation of toric IOL is deemed the most effective choice for correcting corneal astigmatism and reducing postoperative spectacle dependence. The IOL-capsular complex is formed after cataract surgery and intraocular lens (IOL) implantation. Early postoperative mechanical wrapping of the anterior and posterior capsules plays a significant role in preventing IOL decentration and tilt, as well as formation of the IOL-capsular complex which reduces the incidence of posterior cataract opacity. IOL decentration ≥ 0.4 mm or/and IOL tilt ≥7degree were considered clinically significant because of poor post-surgery visual quality especially for optical sophisticated IOLs such as toric IOLs. IOL instability could decrease the curative effect of toric IOL. There are numerous types of toric IOLs; however, AcrySof IQ and TECNIS toric IOL are most frequently used in the Ophthalmology Hospital of Wenzhou Medical University. AcrySof IQ IOL has some differences compared with TECNIS toric IOL. IQ has a modified L haptic design while TECNIS® toric IOL has a modified C haptic design. AcrySof IQ IOL has a discontinuous 360˚ posterior square edge while TECNIS toric IOL has a continuous 360˚ posterior square edge. The AcrySof IQ IOL cylinder power models include 1.00, 1.50, 2.25, 3.00, 3.75, 4.50, 5.25 and 6.00 D. The Tecnis IOL cylinder power models include 1.00, 1.50, 2.25, 3.00 and 4.00 D. Previous study pointed that patients with cataracts with corneal astigmatism achieved comparable improvement in visual acuity, astigmatism correction, CS（sensitive contrast）, rotational stability and satisfaction, following AcrySof and TECNIS toric IOL implantation. However，some other studies found that the Acrysof toric IOL showed significantly greater rotational stability than the Tecnis toric IOL and the rate of surgical IOL repositioning was higher in eyes implanted with TECNIS than with AcrySof toric IOLs for astigmatic correction. Currently, there is no literature guidance to compare the results of cataract surgery combined various types of toric IOLs implantation in patients using CASIA2. The novel anterior segment optical coherence tomography (AS-OCT) device, CASIA2 can accurately evaluate the IOL capsule bending and the lens position after cataract surgery. Also, CASIA2 can be used to documented the dynamic changes of IOL-capsular complex after surgery.
The purpose of this study is to establish if LFR-260 (investigational device) is not inferior in effectiveness to a traditional phoropter (control device) when applied in visual acuity test in subjects undergoing a full routine eye examination. LFR-260 proposes to provide information of the visual capabilities of the patient. The test will be provided and supervised by a qualified eye care provider. The informed consent, screening, randomization (into the order of visual test device used), (visual) device testing (to include precision testing, remote and offsite testing) will all occur at a single visit.
This is a Multi-center, single-arm and non-masked study whereby patients undergoing routine cataract surgery be implanted with a hydrophobic acrylic monofocal toric intraocular lens PODEYE TORIC (model POD T 49P).
The purpose of this open controlled multicenter trial is to assess the impact of use of an amniotic membrane on post PKR recovery.