Active clinical trials for "Cataract"

Ocular surface disease (OSD), particularly dry eye, is one of the most common conditions seen by ophthalmologists. Dry eye (DE) is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance, and tear instability. DE significantly reduces quality of life and affects 5-30% of the population. As the proportion of individuals over age 60 increases because of greater life expectancies, we can anticipate the number of people with dry eye will also increase, which represents a major challenging for aging societies, like the Chilean one. In the last few years clinical research on OSD is being intensely focused on diagnostic criteria, treatment strategies, methods used in diagnosis and better correlations between symptoms and clinical test results. All these lines of interest aim to improve the understanding of alterations and consequences occurring in the ocular surface disorders. Diagnostic testing is greatly valuable both for the detection of early changes due to DE and also to grade the severity of surface disease. The most commonly performed tests include the Schirmer test, tear break up time (TBUT), and ocular surface staining. However, newer point-of-care diagnostics tests such as tear osmolarity and matrix metalloprotease-9 (MMP-9) have been shown to have a high sensitivity and specificity in diagnosing ocular surface dysfunction. Given that ocular surface dysfunction has been shown to have an adverse impact on visual function and can worsen after surgery, it is critical to identify and address any tear film and ocular surface abnormalities before cataract surgery. In the setting of preoperative cataract surgery planning, DE disease and meibomian gland dysfunction can impair critical refractive measures such as keratometry values worsening surgical outcomes. To the best of our knowledge there are no ongoing or published studies that have evaluated DE and OSD as evidenced by either an abnormal tear-film parameter (elevated MMP-9 or abnormal osmolarity), or corneal surface and meibography evaluation findings (using novel non-invasive technology) in patients previous and after cataract surgery.

To perform a retrospective investigation of the CT Lucia 601 IOL implantation in the sulcus

The study designed to compare the effects and the safety of adding dexmedetomidine to local anesthetics and its intravenous administration in subtenon block in patients undergoing cataract surgery.

With the advancement of cataract eye surgery and wavefront sensors, the previously unquantifiable refractive measurements have been identified and the high order aberrations have shown their effect on high resolution imaging. In the human phakic eye, the shape of the normal cornea induces average positive spherical aberration and remains unchanged over time, whereas the crystalline lens has a negative spherical aberration. As a result, overall spherical aberration in the young eye is low. However, the compensation slowly decreases with the aging lens and is fully lost after cataract extraction and implantation of a standard intraocular lens. Optical studies showed that conventional biconvex spherical intraocular lenses add their intrinsic positive spherical aberration to the positive spherical aberration of the cornea resulting in image imperfection and blur. As a useful side effect, this also increases the depth of focus -often referred to as pseudo-accommodation. New Aspheric intraocular lenses designs currently in use impart negative spherical aberration, about 0.17 to 0.20 microns of negative spherical aberration. This added negative spherical aberration partially corrects the average amount of corneal positive spherical aberration & compensate for its effect. Our study will include (FocusForce foldable aspheric intraocular lens, Bausch & Lomb, New Jersey, USA) as an example of this type of negative spherical aberration intraocular lenses. In order to improve retinal image quality without compromising depth of field, or introducing other aberrations, aberration-free aspheric intraocular lenses were developed with no inherent spherical aberration. The other intraocular lens targeted in our study (Akreos AO Microincision lens, Bausch & Lomb, New Jersey, USA) is an example of this type of IOLs.

Gabapentin pretreatment may reduce hyperalgesia occurring at the second surgery in serial, bilateral cataract surgery.

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.

It is a comparative study of Safety and Efficacy of Canaloplasty and Non-penetrating Deep Sclerectomy Combined With Phacoemulsification to Treat Glaucoma and Cataract. It is a Randomised, Prospective Study.

The purpose of this study is to assess the long-term safety of the Glaukos® iStent® Trabecular Micro-Bypass Stent Model GTS100 in conjunction with cataract surgery vs. cataract surgery only, in subjects with mild to moderate open-angle glaucoma.

This study will evaluate the safety and efficacy of three doses of C-KAD Ophthalmic Solution in patients with loss of visual function due to age-related nuclear cataract

To assess the risks of intra- and postoperative bleeding tendency associated with cataract surgery by phacoemulsification in patients on coumadin and antiaggregant treatments. Design: Consecutive prospective study.