View clinical trials related to Cataract.
Filter by: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.
Pterygium is known to induce with-the-rule astigmatism. Excision of pterygium will steepen the cornea and reduce corneal astigmatism. We postulate that the alteration of keratometry reading will indirectly affect the IOL power calculation in cases with concurrent pterygium and cataract. Concurrent pterygium and cataract is common in Hong Kong and other tropical regions. The effect of pterygium excision on intraocular lens power calculation is investigated.
Pterygium is known to induce with-the-rule astigmatism. The corneal curvature along the long axis of the pterygium body is flattened. The excision of pterygium will result in steepening of the cornea and reduction of astigmatism. Therefore, the effect of pterygium excision on intraocular lens (IOL) power calculation has been examined in our previous study. The study confirmed that pterygium can cause alteration of IOL power. The determination of IOL power for cataract surgery is usually calculated from IOL formula called SRK II formula. IOL power = A - (2.5 x AL)-(0.9 x K). Variable A denotes the A-constant of the intraocular lens which is dependent on the IOL material and refractive index. Other variables for input include axial length (AL) and keratometry (K). A larger K reading will result in a lower estimated IOL power and vice versa. Previous studies have documented simultaneous cataract and pterygium operation resulted in reasonable visual outcome without adjustment of IOL power. With the presence of a pterygium, the cornea is flattened and lead to a reduction of K value and over-estimation of calculated IOL power. This randomized controlled trial is designed to compare the refractive outcomes of sequential and simultaneous pterygium and cataract operation. Pterygium excision should be done with various adjuvant therapies to minimize recurrence. Our previous studies reliably demonstrated limbal conjunctival graft and mitomycin C were effective methods to achieve low pterygium recurrence. We use limbal conjunctival autograft as the adjuvant therapy in the current study because this method is safer to be performed either alone or in combination with phacoemulsification. We avoid using mitomycin C as the adjuvant therapy in order to minimize the possibility of intraocular toxicity due to seepage.
This study will evaluate potential candidates for future clinical research studies related to diagnosed or undiagnosed genetic eye disorders or diseases. It will not test any new treatments, but it may arrange for standard treatments for existing eye disorders. The purpose of the study is to train eye doctors and medical researchers at the National Institutes of Health in appropriate methods and procedures for treating patients with genetic eye diseases, and to expand the pool of possible participants for future research studies and trials on eye health. Volunteers for this study may be adults and minor children who have been diagnosed with or are at risk for having a genetic eye disease. Candidates may not have any other medical conditions that would interfere with the researchers' ability to perform the examinations and procedures required for this study. Participants will give a complete medical and family history and undergo a series of tests and procedures as part of this research study. The procedures include a full eye examination and vision testing, electrooculography and an electroretinogram to examine the function of the retina, and flourescein angiography to provide information on the flow of blood in the participant's eyes. Participants will provide research material for further studies by giving a blood sample to be held for genetic testing and analysis, and adult participants will also undergo a skin biopsy to provide cell tissue for additional research material. At each clinic visit, participants will receive treatment for their genetic eye disease as needed, including medications or surgical procedures. Participants may remain a part of this study for up to three years.
The purpose of this study is to evaluate the visual outcomes and patient satisfaction after implantation of a toric IOL in patients with predicted residual corneal astigmatism between 0.75 and 1.00 D. Cataract is prevalent throughout the world and IOLs are routinely implanted after the extraction of the cataractous lens. It is the most frequently performed surgery in the United States with an estimated 2-3 million procedures performed annually. With the aging population on the rise, as well as the increasing popularity of refractive intraocular lenses, the number of intraocular surgeries continues to rise. Over the years, the surgical technique has evolved from intracapsular extraction to modern phacoemulsification. This development has helped with the evolution of IOLs as well. The IOLs have advanced extensively: different materials and designs are available, permitting implantation through smaller, sutureless incisions. Traditional IOLs are of monofocal design providing vision at one distance, typically far; and correct mainly the spherical component of the refractive error. However, there are patients with corneal astigmatism that require additional surgical treatment such as laser correction (laser in situ leratomileusis, LASIK; photorefractive keratectomy, PRK) or limbal relaxing incisions, RLI). Another alternative is the use of a toric IOL, which has been especially designed to correct both the sphere and the astigmatism. The ACRYSOF Toric IOL is intended for primary implantation in the capsular bag of the eye for visual correction of aphakia and preexisting comeal astigmatism in adult patients with or without presbyopia, who desire improved uncorrected distance vision, reduction of residual refractive cylinder and increased spectacle independence for distance vision. The treatment selection of the corneal astigmatism depends on the amount of cylinder as follows, between 0.25 and 0.75 D creating the surgical incision on the steep axis; between 0.75 and 1.75 D, RLI; between 1 and 2.25 D, toric IOLs; and between 1 and 3.00 D, LASIK/PRK.
Although commonly used in cataract surgery, the use of the blue light-filter IOLs in vitrectomy combined with cataract surgery has not been reported yet. A prospective controlled clinical trial was designed to evaluate the effect of the blue light-filter IOL on the surgeon's ability to perform specific vitreoretinal procedures and on the patients' outcome.
The long-term goal of this project is to utilize very high-speed optical coherence tomography (OCT) technology to guide surgical treatments of corneal diseases. OCT is well known for its exquisite resolution, but until recently it has not had sufficient speed to capture the shape of the cornea because of eye motion during OCT scanning. The development of Fourier-domain (FD) OCT technology has made the requisite speed possible. The objective of this project is to develop methods for imaging the cornea with an FD-OCT system that will precisely measure corneal shape and use this information to guide surgery. Cataract surgery in patients with previous laser vision correction often leads to significant near- or far-sightedness, a problem that could be resolved by using a more accurate intraocular lens power selection formula based on the measurement of corneal refractive power with OCT.
This is a 16-day study to evaluate the safety and efficacy of ketorolac eye drops for the treatment of inflammation and pain associated with cataract surgery.
This is a 16 day study to evaluate the safety and efficacy of ketorolac eye drops for the treatment of inflammation and pain associated with cataract surgery
Purpose: Study the effect of nepafenac ophthalmic suspension 0.1% to prevent post-operative cystoid macular edema following uncomplicated cataract surgery Participants: Patients having cataract surgery at UNC who meet eligibility criteria Procedures (methods): Patients will have pre and post-operative vision measured and optical coherence tomography (OCT) testing, also cataract density and intraoperative phacoemulsification parameters including ultrasound power and ultrasound time will be measured. Patients will be randomized into two groups. Group 1 will be treated with standard post-operative cataract management. Group 2 will be treated with standard post-operative cataract management plus topical nepafenac for one month. Post-operative macular thickness will be studied by analyzing the visual acuity and OCT measurements at two months post surgery.