View clinical trials related to Astigmatism.
Filter by:The purpose of this study is to evaluate functional vision associated with rotational stability at blink of DAILIES® AquaComfort Plus® Toric (DACP T) compared to 1-DAY ACUVUE® MOIST® for Astigmatism (1DAM A).
This study will compare toric intra-ocular lens (IOL) with limbal relaxing incisions (LRI) in correcting astigmatism in patient undergoing standard cataract surgery. Astigmatism is unequal curvature of the eye; the eye is oval rather than spherical. Uncorrected astigmatism of greater than approximately 0.75 diopters (D) can cause visual blurring, ghosting of images or halos. Over 20% of patients undergoing cataract surgery have astigmatism which is likely to have been corrected by spectacles. Cataract surgery involves the replacement of the natural opacifying crystalline lens with a clear artificial plastic intra-ocular lens (IOL). The lens power can be selected to correct the patient's glasses prescription. The most widely used IOLs only correct glasses at one distance i.e. either near or distance. Residual astigmatism after cataract surgery will need glasses for correction which is undesirable for many patients. Limbal relaxing incisions (LRI) are circumferential partial thickness cuts to the clear window of the eye (cornea) during surgery. These LRIs can correct corneal astigmatism and have no additional risk of complications. Alternatively, toric IOLs are available which correct astigmatism inside the eye. They have been available for routine use in the last few years; technology has markedly improved and the lenses have become cheaper. Studies have suggested toric IOLs provide better vision after cataract surgery than the regular IOLs. Toric IOL are widely used in the private practice and increasingly in the National Health Service (NHS). LRIs are cost effective for treating astigmatism however their predictability is believed to be lower than toric IOLs. As there are no randomised controlled trials comparing the outcomes between LRIs and toric IOLs. This research will address this gap in knowledge and accordingly from this research future practice will be able to provide treatment to patients with information about the best outcomes.
The objective of this study is to evaluate the fitting and visual outcomes of Nexis Lens, made of silicone commonly used in the contact lens industry, on healthy eye with or without astigmatism.
This study was conducted to evaluate changes of reduction of corneal astigmatism with toric intraocular lens(IOL) in congenital cataract.
The purpose of the study was to identify corneal epithelial- and stromal-thickness distribution patterns in keratoconic eyes using spectral-domain-optical coherence tomography (SD-OCT). Study Hypothesis: SD-OCT provides necessary details about the distribution of corneal epithelial and stromal thicknesses for identification of a pattern characteristic for early keratoconus.
Correlating the accuracy of a refraction done over telemedicine to that of a standard refraction, with a study hypothesis that the results will be equivalent.
The purpose of this clinical trial is to demonstrate that treatments generated by an investigational algorithm reduces spherical aberration compared to currently available iDesign treatments.
Purpose of this study is to compare the astigmatic power of the toric IOL obtained from the AcrySof toric calculator, TECNIS toric calculator, and iTrace toric calculator in a group of patients with preoperative with-the-rule (WTR) and against-the-rule (ATR) corneal astigmatism. The study included 100 eyes with cataract and greater than 0.75 diopter of corneal astigmatism, and the subjects were divided into WTR and ATR group. Keratometric value was measured using autokeratometry, IOLMaster partial coherence interferometry (PCI), iTrace incorporating corneal topography and ray-tracing aberrometry. Based on measured values, toric IOL power calculations were performed using AcrySof, TECNIS and iTrace toric calculators.
The aim of this study is to compare the clinical performance of the Biofinity Toric (comfilcon A) contact lens, versus Air Optix for Astigmatism (lotrafilcon B) over 1 month of daily wear.
The purpose of this study is demonstrate substantial equivalence of an investigational contact lens disinfecting solution to a commercially available contact lens solution in gas permeable lens wearers.