Eye Surgery: THE Presbia Flexivue Microlens™ Procedure
The procedure and equipment needed for the insertion of the Presbia Flexivue Microlens™ are similar to those currently utilized in LASIK. Integrating the same technologies in equipment and processes to modern LASIK practices, the Presbia Flexivue Microlens™ system provides treatment options for presbyopic patients beyond the common use of reading glasses or monovision contact lenses.
Undergoing any surgical procedure requires serious consideration. Ideal candidates for the Presbia Flexivue Microlens™ procedure are identified through a thorough prerequisite qualification process that examines the current health and condition of the eye.
Presbia has developed a specialized training program including patient identification as well as procedural operations using the proprietary Presbia Flexivue Microlens™. Presbia’s top-tier Medical Advisory Board supervises the corporate clinical policies for patient selection as well as pre- and post-operative reporting, which includes patient lifestyles.
Presbia, the clear leader in near vision restoration, enables presbyopic patients to free themselves from dependence on reading glasses and contact lenses.
Presbia has extensive clinical and safety data from both clinical studies and commercial sales.
In preliminary of study of 40 emmetropic patients between the ages of 45 and 60 were implanted with the Presbia Flexivue Microlens™ using a femtosecond laser pocket.
Patients achieved dramatic improvements in their near vision after just one week, from pre-operative vision of 20/100 to 20/25-1. The 12-month results show that the Presbia Flexivue Microlens™ continues to improve near vision over time and produces stable near vision after a full year of implantation without any medical complications.
Over a period of 12 months, the average uncorrected near visual acuity of the patients' operated eye improved from 20/100 pre-operatively to 20/25 after surgery. In addition, the study also showed that patients experienced no change in their distance visual acuity using both eyes, although the distance vision in only the operated eye did show declines of about two lines on the Snellen chart. All patients recorded a binocular distance vision of 20/25 or better within one-month of the surgery, with continued improvement over time.
Drs. Pallikaris and Fantozzi reported that during the 12-month time period after implantation, none of their patients experienced any degradation to the optical system and no major adverse events were reported with the Presbia Flexivue Microlens™.
In addition, patients in this study reported very high satisfaction rates one year after implantation with 98 percent of patients reporting that uncorrected near vision in the implanted eye was either good or excellent, and 100 percent of patients reporting that their uncorrected binocular distance visual acuity was either good or excellent.
Knowledge About Your Eyes
The eye functions like a camera. Light rays enter the eye through the cornea, which provides most of the focusing power. Light then travels through the lens where it is fine-tuned to focus properly on the retina. The retina, at the back of the eye, acts like the film in a camera. Light is changed by the retina into electric impulses that are carried by the optic nerve to the brain. For a person to see clearly, light must be focused precisely on the retina.
The first surface encountered by a ray of light is the tear film. The eye's surface must be kept moist at all times. To achieve this, glands in and near the eyelids produce both tears and special oil which mix together and coat the eye. This tear film coats the cornea, which normally is the crystal-clear window to the eye. Deficiencies in tear production (dry eye) can impair vision and cause redness or discomfort. Behind the cornea, we enter an area called the anterior chamber, which is filled with a fluid called the aqueous. The aqueous is normally clear like water and is responsible for maintaining the pressure of the eye. Disturbances in the production or drainage of the aqueous can result in high pressure in the eye and glaucoma.
The next structure encountered is the crystalline lens. The lens is responsible for focusing light onto the retina. It changes shape slightly to allow us to change focus between objects that are near and those that are far. As a person ages, the lens becomes less flexible and less able to "accommodate" or change focus. This is called presbyopia. When a patient becomes presbyopic, he or she often needs to wear reading glasses or switch to bifocals. Eventually, the lens loses its original clarity and can become yellowish or cloudy. This condition, called cataract, degrades the quality of the image focused on the retina. When the cataract becomes dense enough to interfere with vision, the lens can be replaced with a clear artificial lens implant during cataract surgery.
Inside the anterior chamber is the iris. This is the part of the eye responsible for a person's eye color. The iris acts like the diaphragm of a camera, dilating and constricting the pupil to allow more or less light into the eye.
The vitreous is a jelly-like substance that fills the body of the eye. It is normally clear. In early life, it is firmly attached to the retina behind it. With age, the vitreous becomes more water-like and may detach from the retina. Often, little clumps or strands of the jelly form and cast shadows that are perceived as "floaters." While frequently benign, sometimes floaters can be a sign of a more serious condition such as a retinal tear or detachment, and should be investigated with a thorough ophthalmologic examination.
Finally, light reaches the retina, a thin tissue lining the innermost wall of the eye. The retina acts much like the film in a camera. The retina responds to light rays hitting it and converts them to electrical signals that are carried by the optic nerve to the brain. The outlying parts of the retina are responsible for peripheral vision while the center area, called the macula, is used for fine central vision and color vision. The very center of the macula is called the fovea. It has a very high concentration of special cells called cones, which make it the only part of the retina capable of 20/20 vision.
The Optic Nerve
The optic nerve is the structure that takes the information from the retina as electrical signals, and delivers it to the brain, where this information is interpreted as a visual image. The optic nerve consists of about one million nerve fibers. The position in the back of the eye where the nerve enters the globe corresponds to the "blind spot" since there are no rods or cones in this location. Normally, a person does not notice this blind spot, since rapid movements of the eye and processing in the brain compensate for the absence of information.