View clinical trials related to Corneal Astigmatism.
Filter by:The main goal of this study is to evaluate real-world visual outcomes, rotational stability, and patient reported visual disturbances with a non-diffractive extended vision presbyopia and astigmatism correcting intraocular lens in patients with significant corneal astigmatism undergoing bilateral cataract surgery. This is important to ensure optimal results for patients who wish to have intraocular lenses that correct presbyopia and astigmatism, thus giving them a greater independence from spectacles and a better quality of life.
The purpose of this study is to evaluate the effectiveness and safety of the TFNT20 low cylinder power intraocular lens when implanted in the eye to replace the natural lens following cataract removal.
The purpose of this study is to evaluate the clinical performance of the ACRYSOF® IQ PanOptix® Toric Trifocal intraocular lens (IOL) when implanted in the eye following cataract removal in an Asian population.
The purpose of this study is the investigation of biomechanical properties of the cornea using computer-aided data analysis. Currently, it is known that keratoconus and glaucoma are ocular disease that are associated with biomechanical alterations of the cornea. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. In glaucoma, the information about corneal alterations serves in two ways, first, correct measurement of intra ocular pressure (IOP); second, early diagnosis of suspects before visual field defects are detectable. Especially, the Corvis ST is an air-puff tonometer that measures intraocular pressure, corneal thickness (CCT) as well as dynamic corneal response (DCR) parameters. Most of the DCR parameters are affected by IOP and CCT: Therefore, algorithm are needed to determine parameters without impact of IOP and CCT that are describe the biomechanical properties of the cornea.
The magnitude of posterior corneal astigmatism was considered negligible due to the smaller difference in the refractive index between the cornea and the aqueous . though ,neglecting the posterior corneal astigmatism lead to errors during calculation of the toric iols (over or under estimation ) . so we aim to determine the percentage of contribution of posterior corneal astigmatism to total corneal astigmatism in a sample of Egyptian population using scheimpflug imaging (Pentacam ).
This is a prospective, multicenter, single-arm, open-label clinical study of the commercially available TECNIS Toric II IOL. The study will be conducted in up to 192 subjects needing unilateral or bilateral cataract surgery in up to 8 sites in United States (US). The subjects will be followed for up to 3-months postoperatively.
The purpose of this study is long-term follow up of patients with corneal diseases to analyze the quality of surgical interventions and diagnosis. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. Overall, a long-term follow up is needed to evaluate an early disease progression as well as corneal stability after surgical intervention.
This is a multicenter, prospective, single-arm, open-label, clinical study of the commercially available TECNIS Toric II, Model ZCU IOL. The study will be conducted in up to 1100 subjects enrolled with 1,000 subjects needing unilateral or bilateral cataract surgery across up to 50 US study sites.
This study will be a prospective, multicenter, bilateral, comparative, three-way masked (Sponsor, subject and evaluator), randomized clinical investigation conducted at up to 15 sites. Up to 300 subjects will be enrolled to achieve approximately 270 bilaterally implanted subjects, resulting in approximately 244 evaluable subjects (122 per lens group) at 6 months. After informed consent is obtained and confirmation that all eligibility criteria are met, the eye(s) may be treated according to randomization. After signing the informed consent form, subjects meeting all eligibility criteria will be randomized in a masked fashion to a treatment group: either the investigational IOL Model ZFR00V or the control IOL Model ZCB00. Prior to randomization, the investigator will choose which eye to operate on first for each subject at his/her discretion based on his/her standard clinical practice (e.g., the eye with the worse cataract, poorer best corrected distance vision and/or more severe optical/visual complaints). All subjects are intended to have bilateral cataract surgery with the second eye surgery occurring after the 1-week postoperative exam for the first eye, but no more than 30 days after the first eye surgery. All subjects will be examined through 6 months postoperatively according to the visit schedule
This study sets out to evaluate the EpiMaster application software for use in predicting the refractive change induced by a trans-epithelial phototherapeutic keratectomy (TE-PTK) procedure in eyes with irregularly irregular astigmatism. If validation criteria are met during the observational phase, the software refractive prediction will be used to plan the refractive correction in TE-PTK treatments.