View clinical trials related to Astigmatism.
Filter by:This non-dispensing study is to evaluate the clinical performance of a test multifocal toric silicone hydrogel contact lens compared to a marketed multifocal toric contact lens (control).
Prospective, comparative, randomized, non-masked clinical study to compare the a digital refraction with LogMAR VA testing utilizing trial lenses, to standard manual refraction using a Phoropter, and LogMAR VA testing, in accuracy of visual acuity measurement.
Keratoconus is a bilateral (but usually asymmetrical) non-inflammatory progressive thinning process of the cornea. It manifests as characteristic cone-like ectasia of the cornea associated with irregular stromal thinning, resulting in a cone-like bulge , which causing irregular astigmatism and vision impairment.
The aim of this prospective study is to evaluate the clinical performance of fanfilcon A toric and lotrafilcon B toric contact lenses after 1 month of wear in each pair.
the purpose of this study was to assess the efficacy of custom made toric intraocular lens implantation in patients with simultaneous post-DALK high corneal astigmatism and cataract.
The purpose of this research study is to compare the performance of two different types of Alcon soft toric study contact lenses to obtain information on study lens orientation.
The recently introduced toric V4c toric ICL (STAAR Surgical Company, Monrovia, CA, USA) has been designed with a 360-µm central hole to allow aqueous humor to flow without the need for an iridotomy. As far as the investigators certain, there have been not well-established prospective studies on the role of the V4c toric ICL for myopic astigmatism correction. Therefore, the present study aimed to investigate the clinical outcomes and rotational stability and to analyze factors that influence the rotational stability in V4c toric ICL implanted eyes prospectively.
The purpose of this study is to clinically confirm the rotational stability of a modified AcrySof IQ toric intraocular lens (IOL) in a Japanese population.
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.
To analyze the difference between measured total corneal astigmatism and actual corneal astigmatism under different region modes and optimize the region setting.