After you enable Flash, refresh this webpage and the presentation should play. Get the plugin now. Help Preferences Sign up Log in. To view this presentation, you'll need to enable Flash. Show me how After you enable Flash, refresh this webpage and the presentation should play. View by Category Toggle navigation. Products Sold on our sister site CrystalGraphics. Accommodative and Multifocal IOLs.
Used to treat nearsightedness myopiafarsightedness hyperopia and the These light rays are focused directly onto the retina, the light-sensitive tissue lining the back of eye.
The retina converts light rays into impulses, sent through the optic nerve to your brain, where they are recognized as images. Four types of Accommodating iol ppt background error Myopia nearsightedness Hyperopia farsightedness Astigmatism Presbyopia 4 Refractive errors myopia In myopia nearsightednessthere is too much optical power in the eye The distance between the cornea and the retina may be too long or the power of the cornea and the lens may be too strong.
Light rays focus in front of the retina instead of on it. Close objects will look clear, but distant objects will appear blurred. Myopia, or nearsightedness 5 Refractive errors hyperopia In hyperopia farsightednessthere is too little optical power. The distance between the cornea and the retina may be too short. Light rays are focused behind the retina instead of on it. In adults but not childrendistant objects will look clear, but close objects will appear blurred.
Hyperopia, or farsightedness 6 Refractive errors astigmatism In astigmatism, the cornea is curved unevenlyshaped more like a football than a basketball. Light passing through the uneven cornea is focused in two or more locations.
Distant and close objects may appear blurry. When we are young, the lens in our eyes is flexible and is to change focus easily between near and far objects, like an autofocus on a camera. At around age 40, this flexibility begins to gradually decrease, making it more difficult to see objects up close, unless the eye has nearsightedness. The eyes lens, provides your focusing power, has four primary functions Transparency To provide a clear medium through which light rays from an object can reach your retina.
Optical To focus a sharp image of an object on the retina. Anatomic To create a functional barrier between the anterior and posterior segments of the eye.
Accommodation To the eyes refractive power, thus providing clear images of objects over a wide range of distances. A group of outpatient surgical procedures used to alter how your eye focuses light rays on the retina, thereby improving vision and reducing dependence on glasses and contact lenses. In most cases, refractive surgery affects the shape of your cornea to redirect how light is focused onto the retina.
Refractive surgery procedure on the cornea 10 What is refractive surgery? Most refractive surgery is performed on the cornea and affects only the front of your eye, while the Accommodating iol ppt background of your Accommodating iol ppt background will change naturally as you age. In some cases, refractive surgery procedures dont reshape the cornea instead, the eyes natural lens is either replaced or enhanced by an implantable lens that helps correct vision.
An artificial lens that is surgically implanted in the eye, replacing the eyes natural lens. Enables your eye to regain its focusing and refractive ability. The cornea is not reshaped. Used to treat nearsightedness myopiafarsightedness hyperopia and the inability to focus at near with age presbyopia. The accommodative IOL is hinged to work in coordination with the eye muscles. The design allows the accommodative lens to move forward as the eye focuses on near objects, and move backward as it focuses on distant objects.
A multifocal lens has several rings of different powers built into the lens. The part of the lens ring you look through will determine if you see clearly at a far, near or intermediate distance this is sometimes called pseudo-accommodation. The IOL is implanted in a surgical procedure, performed on an outpatient basis under local anesthesia and taking approximately minutes. In addition to a pre-operative eye exam, measurements of the eye are taken to give the surgeon the necessary information to perform the procedure.
These measurements include Refractive error measurement. Pupil evaluation and size measurement. Keratometry measurement of the form and curvature of the cornea. A-scan Measurement of the axial length of the eye from "Accommodating iol ppt background" cornea to the retina. Calculations to determine the correct power of lens IOL Accommodating iol ppt background use. A phoropter is used to measure refractive errors 16 How is the IOL procedure performed?
After the eye is numbed with topical or local anesthesia, one to three small incisions are made close to the edge of the cornea. After the procedure, these incisions are usually self-sealing, requiring no stitches. A tiny, high-frequency ultrasound instrument is inserted into the eye to break up the center of the eyes natural, crystalline lens.
The natural lens is then gently vacuumed out through one of the incisions. The eyes natural lens is suctioned out through an incision 18 How is the IOL procedure performed? An IOL is folded and inserted through the same incision that was used to extract the natural lens. The IOL is then unfolded and placed into the "capsular bag" that originally surrounded the natural lens. Once the accommodative or multifocal IOL is implanted, your eye can focus on near, intermediate and far distances.
Your eye must re-learn how to focus on objects at various distances in order to see clearly. Increased floaters or retinal detachment.
Advanced surgical procedures, including accommodative and Accommodating iol ppt background IOLs, are creating more opportunities for people who want to be less dependent on glasses or contacts.
Surgery may not entirely eliminate your need for corrective lenses. If an accommodating or multifocal IOL is used, then reading as well as distance vision may be improved.