View clinical trials related to Astigmatism.
Filter by: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.
The refractive combination of high hyperopia with high astigmatism is difficult to treat surgically. In addition, there are not many suitable options to offer such patients presenting with this condition. The method used at the EYE Hospital Pristina using fresh lenticule implantation by ReLex-SMILE is safe and effective method. Fresh Corneal Implantation is a safe treatment for hyperopia with high astigmatism comparing with refractive IOL implantation (loss of accommodation, endophthalmitis). Its primary objective is to increase visual acuity, accommodation process, patient satisfaction which makes patient to enjoy a happier life. We believe this study will be the future of refractive surgery for treating high hyperopia.
The objective of this study is to evaluate the long term (i.e. 24 months) clinical performance of the Visian® Toric Implantable Collamer® Lens (ICL).
Photorefractive keratectomy (PRK) with excimer laser has been used successfully to treat myopia, hyperopia, and astigmatism in adults for over 35 years. Children with high refractive errors that go untreated will develop severe amblyopia. PRK can normalize high refractive errors and potentially improve the visual acuity in affected children. The purpose of this study is to investigate whether children with high anisometropia or isoametropia with amblyopia that are nonresponsive to standard therapy and receive PRK develop better longterm visual acuity.
The assessment of the refractive state of the eye is a fundamental and important part of ophthalmic and optometric clinical practice. The development of an unsupervised online subjective refraction method makes a refraction more accessible and can be quite cost-saving. In this study, the investigators want to validate an online refraction method which was recently created in the Netherlands. The study comprises two different set of participants: Part one contains fifty healthy volunteers, 18-40 years of age, with a refractive error and no other ophthalmic pathology. Part two contains fifty patients with an ophthalmic pathology. The online refraction outcomes will be compared to a manifest refraction and automated refraction in a cross-sectional study design.
The investigators are comparing outcomes of LASIK surgery using a high definition wavefront-guided laser to a wavefront-optimized laser in patients with nearsightedness with and without astigmatism.
Toric intraocular lens (IOL) is now widely used for the cataract surgery with preoperative corneal astigmatism. Symptomatic epiretinal membrane (ERM) is often treated with 25-gauge transconjunctival sutureless vitrectomy, resulting in good visual recovery. So far, however, limited information is available on the the stability of axis rotation, astigmatism correction, and improvement in uncorrected distance visual acuity, using astigmatism-correcting IOL in a 25-gauge transconjunctival sutureless vitrectomy combined with cataract surgery. In the current study, eyes with a preoperative corneal cylinder of more than 0.75 diopter had a triple procedure for idiopathic ERM using a toric IOL. Outcome measures will be the amount of IOL axis rotation, uncorrected visual acuity, corrected distance visual acuity, and corneal and refractive astigmatism up to 6 months postoperatively. We are expecting to show that postoperative IOL axis stability is similar to that reported for cataract surgery alone in vitrectomy (triple procedure) for idiopathic ERM with a toric IOL.
This phase IV study is an open, prospective, single-center, single-surgeon bilateral eye study to investigate the bilateral uncorrected intermediate visual acuity of presbyopic hyperopic patients, who have been treated with Presbyopia Algorithm SUPRACOR.
This clinical study has been planned to evaluate the safety and effectiveness of the SUPRACR presbyopic excimer laser treatment algorithm for myopic eyes developed for applying to the cornea of the human eye in a single center. The developed software algorithm uses the subjective refraction of the eye to create a treatment for the distance vision correction. This part of the treatment does not show any difference to a regular aspheric LASIK treatment for myopic cases. In addition to the treatment for the distance vision an additional central ablation component will be added to address the near vision. The study design is applied as a single center unilateral eye safety and effectiveness study of the SUPRACOR presbyopic algorithm for myopia with a 3 months postoperative follow up.
This is a multicenter study to evaluate the clinical performance of the SynergEyes A2 lens in patients with refractive errors with or without astigmatism.