Active clinical trials for "Astigmatism"

The main goal of this study is to compare traditional cataract surgery with two new technologies: the femtosecond laser and the new Active Sentry handpiece. The femtosecond laser is used in several fields of ophthalmology and allows to automate multiple key steps of cataract surgery. The new generation of handpiece called Active Sentry has the particularity to detect the pressure inside the eye in real time and to adjust it to avoid large variations. Theses technologies would potentially increase the efficacy and safety of standard cataract surgery. This study therefore aims at evaluating the differences in cumulative dissipated energy and endothelial cell loss between femtosecond laser assisted cataract surgery with the new Active Sentry handpiece compared to standard phaco with new (Active Sentry) or older handpieces (OZil).

Aberrations are the spreading of light from a point focus. Aberrations of the eyes can be objectively evaluated with a wavefront aberrometer. Lower order aberrations such as defocus and astigmatism can be corrected with glasses and traditional/disposable soft contact lenses. Patients with ectatic corneal disease, such as keratoconus, or irregular astigmatism cause by surgery, trauma or disease, experience vision that is unlikely to be adequately corrected with glasses or disposable soft contact lenses due to higher order aberrations (HOA). HOA's cause halos, flare, glare, starbursts, doubling, smearing or ghosting of vision. Specialty contact lenses, such as scleral lenses, can be used to mask the irregularity of the cornea, reducing HOA's and improving vision. In many patients the resultant vision, though improved, still has some level of residual HOA's affecting the quality of vision. Custom scleral lenses with customized wavefront guided optics can be used to reduce residual HOA's and improve vision further. These lenses have been referred to as higher order aberration correcting scleral lenses or HOA correcting sclerals and wavefront guided scleral lenses or WFG sclerals.

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.

This study evaluates differences in postoperative visual outcomes between patients receiving Topography-Guided LASIK in one eye and Small Incision Lenticule Extraction in the other eye.

The purpose of this study is to compare developmental outcome for young children (12 to 35 months of age) with astigmatism meeting American Academy of Ophthalmology spectacle prescribing guidelines and who are prescribed and provided spectacles for either Full-Time wear (encouraged and reinforced) or Ad Lib wear (wear dependent on child acceptance).

To evaluate patient reported outcomes associated with quality of vision before and after treatment with Contoura Vision Topography-Guided LASIK.

To assess the rotation stability of toric intraocular lenses between sitting or routine settings (sitting, going around) after cataract operation.

Comparing post-operative visual acuity and patient reported satisfaction between Contoura with Phorcides and WaveLight Wavefront Optimized.

The investigational devices are approved intraocular lenses (IOL) intended to be implanted after phacoemulsification in individuals suffering from age-related cataract with the need of cataract surgery. Within the study, three different IOLs will be investigated and separately evaluated. Cataract surgery with IOL implantation will be performed in subjects who have signed an informed consent form. Postoperative examinations will be postoperative refraction, visual acuity, slitlamp examination, and rotation of the IOL within 1 hour, 1 week, 1 month and 4-7 months. In the Alcon Clareon toric and RayOne EMV toric groups, patients receive a toric IOL according to their preoperative astigmatism

In cataract surgery, the opaque lens is replaced by an artificial intraocular lens. The procedure also allows for correction of an refractive error such as myopia, hyperopia or astigmatism. In case of correction of an astigmatism, the axis intraocular lens has to be alligned to the axis of the corneal astigmatism. There are serveral options, the intendet position of the axis can be marked on the cornea, either manually using ink and a special caliper or with an automatic laser device. The aim of this study is to assess the accuracy of topography guided automatic marking of the intended IOL-axis in toric IOL-implantation in femtosecond laser assisted cataract surgery (FLACS)