View clinical trials related to Intraocular Lens.
Filter by:During cataract surgery an artificial intraocular lens (IOL) is implanted in the eye to replace the lens and to correct the refraction for distance vision. Misalignment of IOLs can cause severe loss of visual quality. Different types of misalignment are known. Tilt, one type of IOL misalignment is thought to play a negative role for the optical performance in eyes with IOL designs, especially, if they have aspheric, toric, or multifocal optics. Various methods to measure IOL misalignments have been described. Studies assessing the IOL position have used subjective grading methods at the slit lamp examination or a Scheimpflug camera to assess IOL decentration and tilt. The subjective grading at the slitlamp may display considerable variability between examiners. This method is more qualitative than quantitative and does not allow fine resolution when reporting IOL tilt. The fact that the patient has no standardized target to focus on makes the method even less reliable. Scanning methods such as Scheimpflug photos require a very well dilated pupil exceeding 6mm to assess the IOL position. Additionally, it can be difficult to identify the anatomical structures of the eye that need to be used as points of reference. Scheimpflug camera images have been used for assessing IOL tilt previously, but erroneous results, often due to corneal magnification, have diminished their widespread use. Another possibility to assess tilt is the use of Purkinje reflexes. The light reflections of Purkinje images at ocular surfaces to evaluate ocular alignment have recently been utilized. Since light is reflected at all interfaces of media with a difference in refractive index, these reflections, called Purkinje images, can be used to assess tilt and decentration of IOLs. Two different clinically applicable Purkinjemeter system provide the measurement of IOL decentration and tilt. The main problem with Purkinje meters is accessibility, as there are only a few prototypes available worldwide. The most recently developed method for tilt quantification is the use of optical coherence tomography. This method has several advantages compared to the previous methods: OCT based devices are available in most clinics, the resolution of modern OCT devices is high, and the measurements are reproducible. Aim of this study is to measure tilt with two modern OCT based devices and one Scheimpflug camera and to predict the post-operative tilt using partial least squares regression. This method was developed by Wold and introduced to ophthalmology previously.
The purpose of this study is to compare visual performance and quality of life (QOL) following bilateral implantation of a novel non-diffractive extended depth-of-focus (EDOF) intraocular lens (IOL) (AcrySof® IQ Vivity, Alcon, TX, USA) and a trifocal IOL (Acrysof® IQ PanOptix, Alcon, Fort Worth, TX) in a prospective comparative interventional case series.
To compare visual outcomes for various distances, reading speed, contrast sensitivity, glare occurence, defocus curve and subjective satisfaction in patients implanted with the extended depth of focus lens (Tecnis Eyhance) in one eye and monocal aspheric lens (Tecnis ZCB00) in second eye. Patients undergo visit in 3,6 and 12 months after the surgery.
To compare the visual performance of the extended depth of focus (EDOF) intraocular lens (IOL) to bifocal and spherical monofocal IOL
Age-related cataract is the main cause of impaired vision in the elderly population worldwide. In the UK, more than half of people who are over 65 years old have some cataract development in one or both eyes. The only treatment that can restore functional visual ability is cataract surgery where the opacified crystalline lens is removed by phacoemulsification and an artificial intraocular lens is implanted. It is estimated that around 10 million cataract operations are performed around the world each year. Cataract operations are generally very successful, with a low risk of serious complications. During the past two decades, cataract surgery underwent tremendous change and modernisation resulting in today's small incision phacoemulsification surgery and a safe technique with a short rehabilitation time for the patient. Traditional spherical monofocal intraocular lenses (IOLs) restore best-corrected vision and may lessen the need for spectacles. These IOLs correct only the spherical portion of the total refractive error and do not correct corneal astigmatism. Astigmatism is a visually disabling refractive error affecting the general population, especially those with cataract. At least 15% to 20% of cataract patients have 1.5 diopters (D) or more of corneal or refractive astigmatism. With increased patient expectations, the trend is not only to remove the cataract but also to address the problem of pre-existing astigmatism at the time of surgery. Surgical-induced astigmatism can be reduced by smaller incisions, i.e. microincision cataract surgery (MICS), which by definition is surgery performed through incisions smaller than 2.0 mm, reducing the need for suturing. This results in better corneal optical quality, thus improving visual outcomes. There are also other surgical options to correct preexisting astigmatism during cataract surgery like: selectively positioning of the phacoemulsification incision; astigmatic keratotomy with corneal or limbal relaxing incisions; excimer laser refractive procedures such as photorefractive keratectomy, laser in situ keratomileusis, and laser-assisted subepithelial keratectomy; or implanting pseudophakic toric posterior chamber intraocular lenses (IOLs). Toric IOLs have been shown to result in good visual and refractive outcomes. Combined with MICS, these IOLs can allow effective correction of cylindrical errors intraoperatively, improving visual quality and thus leading to spectacle independence. Plate haptic and loop haptic toric IOLs have been considered for about a decade but have been associated with postoperative rotational instability. Rotation of a toric lens from its intended orientation degrades its corrective power, with approximately 3.3% loss of cylindrical power for every degree off axis. A misorientation of approximately 30° negates the effectiveness of astigmatic correction, and a misorientation of more than 30° may induce additional astigmatism. Although some patients are asymptomatic despite induced astigmatism, others experience symptoms such as blurred or distorted vision, headache, fatigue, eyestrain, squinting, or eye discomfort. Thus, IOL orientation stability is an essential goal in toric IOL design. RATIONALE The purpose of this study is to assess the axial IOL rotation and optical quality (refraction, visual acuity, contrast sensitivity, decentration and tilt) and capsular bag reaction after micro-incision surgery with an IOL implantation in cataract patients - HOYA Vivinex iSert® model P261.