18 Clinical Trials for Various Conditions
A cataract is a clouding of the lens that occurs naturally with age. Cataract surgery involves removal of the cloudy lens and replacement with an artificial one. A special laser (femtosecond laser) is now being used to help make cataract surgery safer and more accurate . The femtosecond laser can also be used to correct astigmatism, an irregular curvature of the cornea, at the time of cataract surgery through a procedure called astigmatic keratotomy (AK). This study is gathering information about the specific laser settings that are used to perform astigmatic keratotomies (AK) during cataract surgery. This information will be used to improve the outcomes of patients that receive cataract surgery with astigmatic keratotomies in the future.
The investigational enVista IOL, Model MX60Tis equipped with toric optics and axis marks on the posterior surface to minimize the possibility of surgically induced astigmatism.
The purpose is to evaluate the Calhoun Vision Light Adjustable Lens (LAL) and Light Delivery Device (LDD) for reducing astigmatism and improving uncorrected vision after implantation.
To assess which commercially available measurement device is most accurate in measuring low (\< 1.0 D) degrees of corneal astigmatism.
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.
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 is a prospective, multicenter, bilateral, non-randomized, open-label, comparative, 6-month clinical study conducted at up to 50 sites in the USA.
To assess visual performance in patients with low levels (0.5-0.75 Diopters) of corneal astigmatism.
The purpose of this study is to describe rates of spatial distortions related to intraocular lens (IOL) misalignment for ACRYSOF® Single-Piece Toric NATURAL IOL Model SN60T9 when implanted bilaterally into the capsular bag following phacoemulsification in adult patients with bilateral cataract and regular corneal astigmatism. Subjects were implanted with the Model SN60T9 in the first operative (study) eye and either Model SN60T9 or Model SN60T8 in the second operative eye.
The primary goal of the study is to determine if Optical Coherence Tomography (OCT) measurement of corneal power and astigmatism is more accurate than conventional Placido-ring corneal topography. A second goal is to evaluate OCT-based epithelial thickness mapping. The postoperative epithelial thickness variation will be used to calculate refractive effects and calibrate the smoothing parameter in the mathematical model relating corneal mean curvature and epithelial thickness. A third goal is to assess the repeatability of OCT measurements. A fourth goal is to develop a method of estimating the focusing power, astigmatism, and HOA of the crystalline lens based on measurements of the lens' anterior and posterior capsular topographies and positions with the ultrahigh-speed MIT OCT prototype.
Most of the patients presenting for cataract surgery also have pre-existing corneal astigmatism which if left uncorrected can adversely affect visual and refractive outcomes after cataract surgery. Pre-existing astigmatism at the time of cataract surgery can be corrected by either corneal relaxing incisions or implantation of toric IOLs. While the safety and efficacy of these procedures are well established, there are various challenges associated with these techniques that surgeons need to overcome to achieve good outcomes postoperatively. The use of iris registration technology that automatically compensates for cyclotorsion has the potential to improve the alignment accuracy of CRI or toric IOLs. The Cassini Ambient and Catalys Femtosecond Laser incorporate this technology to help cataract surgeons accurately align toric IOLs on the intended axis of implantation or accurately place CRI on the intended meridian. The present study is aimed at evaluating the efficacy of astigmatism correction during femtosecond laser-assisted cataract surgery with Catalys femtosecond laser. The patients will either undergo iris registration guided CRIs or iris registration guided alignment of toric IOLs.
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 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.
The objectives of this study are to evaluate the safety and efficacy, with regards to regression of refractive outcome, as measured by manifest refraction spherical equivalent (MRSE), of two treatment regimens for hyperopic and hyperopic astigmatic subjects: LASIK followed by cross-linking performed with the KXL System and Photrexa ZD™ (Riboflavin Ophthalmic Solution), as compared to LASIK alone.
The purpose of this study was to evaluate and compare postoperative corneal aberrations and visual parameters in patients contralaterally implanted with an AcrySof IQ Toric intraocular lens (IOL) and AcrySof IQ Aspheric IOL with concomitant limbal relaxing incision.
A new multi-purpose solution (MPS)was clinically evaluated against Opti-Free RepleniSH MPS at specific time points over the course of four days. The study was conducted with PureVision lenses.
The purpose of this study is to determine whether the MEL 80 Excimer Laser is effective in the treatment of mixed astigmatism up to 6.0 D, when used as part of the Laser In Situ Keratomileusis (LASIK) procedure.