Clinical Research Directory

Presbyopic Wear Experience With Multifocal Lenses Compared to Single Vision Lenses and Reading Glasses

The purpose of the study is to assess participant experience when wearing multifocal contact lenses compared to spherical contact lenses with reading glasses.

A Planned Study at Multiple Sites is Being Done to Compare the Results of Two Types of Trifocal Toric Intraocular Lenses Used in Cataract Surgery

To evaluate the clinical outcomes and patient satisfaction of two commercially available trifocal toric intraocular lenses Primary Objective: To compare the distance-corrected intermediate visual acuity between the two trifocal toric intraocular lenses. Secondary Objectives: To assess and compare the safety of two trifocal toric intraocular lenses.

Head-to-Head Comparison of Five Enhanced Depth of Focus IOLs and One Monofocal IOL

Study Goal The goal of this clinical trial is to compare how well four different types of artificial lenses (called intraocular lenses or IOLs) help people see after cataract surgery. The main questions it aims to answer are: Which lens gives the best vision at different distances (far, middle, and close)? How satisfied are patients with their vision after surgery? How often do patients still need glasses after surgery? Who Can Participate Adults aged 22 to 85 years who need cataract surgery in both eyes and meet specific health requirements. Study Design Researchers compared six different lens types: TECNIS Eyhance - designed to improve middle-distance vision AcrySof IQ Vivity - extends the range of clear vision LuxSmart - uses special optics for better depth of focus Rayner EMV - uses gradual light-bending technology for smooth vision transition Eycryl SERT - modifies light focus to extend clear vision range CT ASPHINA 409M - standard single-focus lens (comparison group) Participants chose their preferred lens type after learning about each option's benefits and limitations. What Participants Do? Participants will: Have cataract surgery on both eyes (1-2 weeks apart) Complete vision tests at multiple distances Take contrast sensitivity tests under different lighting conditions Fill out questionnaires about vision quality and daily activities Attend follow-up visits at 1 day, 1 week, 1 month, and 3 months This study helps patients and doctors make informed decisions about which type of artificial lens might work best for individual needs and lifestyle.

Photopic and Mesopic Multifocal IOL Performance

Modern cataract surgery has become a refractive procedure. Both, multifocal lens implantation and pseudophakic monovision with monofocal IOLs are effective means to address presbyopia correction after cataract surgery. Historically, diffractive multifocal IOLs have provided improved visual acuity at near and intermediate distances and a greater likelihood of spectacle independence than monofocal IOLs. The light transmittance ratio of the crystalline lens is high and as a monofocal ocular medium that has the ability to modify its shape and geometric properties according to the focal point. Therefore, it is capable of delivering the exact same light energy to the retina, regardless of the distance of the object. Trifocal IOL designs split the light in three focal points. By varying the height of the diffractive step, the amount of light distributed to near, intermediate and distant foci is adjusted according to pupil aperture. The distribution of light to three different foci includes several potential disadvantages, such as loss of visual acuity in mesopic conditions and a loss of contrast sensitivity. Thus, the visual performance of multifocal IOLs depends on several factors, the addition (add) power is a major determinant of the actual range of clear vision, another factor is the light transmittance characteristics of the lens (e.g., the incorporation of a blue light filter). As different trifocal IOLs become available, it is important to have information on their characteristics regarding visual acuity in order to be able to recommend an IOL that meets the individualized needs of each patient. In order to provide the patient with a high visual acuity in all promised distances, these IOLs need to be aimed at and achieve emmetropia. Furthermore, multifocal IOLs need good capsular bag centration, they need to remain as unaffected as possible by capsular bag constriction and remain stable in their axial lens position in order to provide a stable refraction after surgery. The investigators compare the anterior chamber depth stability as marker for positional stability and haptic buckling between two different diffractive IOL designs, one with C-loop haptics and one with plate haptics. Furthermore, the refractive outcome of these IOLs with different designs is examined in photopic and mesopic conditions, as well as visual acuity results for both IOLs.

Effect of Presbyopia Correction on Livelihood and Repayment Among Solar Customers in Western Region, Kenya

With age, people lose the ability to see things that are near them clearly. This is known as presbyopia. Although this is a normal ageing process, it can be corrected with near vision eyeglasses - colloquially known as reading glasses - and people should not have to "put up with" poor near vision. By improving the ability to see things that are up-close, near vision eyeglasses allow people to perform tasks with greater ease. This improves their quality of life, and increases their productivity and income. DOT Glasses provides people in East Africa with a range of eyeglasses, including those to improve near vision. In addition, products sold to communities through loans repaid at regular intervals (known as asset financing), allow people in underserved communities to harness electricity through solar products and to own electronic devices, such as mobile phones. This also improves their quality of life, and increases their productivity and income. Sun King is one of the leading providers of solar products through loans in Kenya. This study will gather evidence and insights from existing Sun King customers with poor near vision in Busia, Siaya, Vihiga and Kakamega. The investigators will explore how much giving people glasses to improve their near vision impacts their ability to make repayments, their incomes and livelihoods, and their overall quality of life. It will also be studied how the glasses affect participants usage of the solar device or mobile phone.

VIS Opti-K Vision Improvement for Presbyopes

The VIS Opti-K device and procedure were used to provide vision improvement to patients with presbyopia.

Quality of Life in Presbyopes Using Single-vision Lens and Progressive Lens Correction

The goal of this clinical trial is to compare the quality of life (QOL) of presbyopes wearing progressive addition lenses (PALs) with that of those wearing single-vision spectacles (SVSs) for near correction. The main questions it aims to answer is: What is the difference in QOL between presbyopes who use SVSs and those who use PALs ? Eligible participants will be randomly assigned in a 1:1 ratio to either the PALs group or the SVSs group.Participants in the progressive lenses intervention group will receive 1-month progressive lens correction in daily life. And participants in single-vision lenses intervention group will use near-vision spectacles during near work and use their original habitual distant glasses for distance tasks for 1 month. The study will compare the QOL scores measured by a 12-item Near Vision-Related Quality of Life questionnaire between the two groups. Additionally, the study will compare the scores measured by the Refractive Status and Vision Profile questionnaire and Visual Analogue Scale questionnaire between the two groups as well as assess the change in the above three questionnaires scores at 1 month following enrollment. And visual acuity of subjects will also be assessed at baseline and at the 1-month follow-up.