Intra-ocular lens implantation has become a popular surgery for people who have vision problems. It has been in development for over 15 years in Europe and is gaining popularity in the United States. New designs, materials, and surgical techniques are being studied to improve patient outcomes and reduce complications. The dramatic increase in vision rehabilitation is accompanied by a slight increase in risks.
Intra-ocular lens implantation
Intra-ocular lens implantation is a surgical procedure that replaces the natural lens inside the eye. The procedure is a common part of cataract surgery. This type of surgery involves inserting a foldable, synthetic artificial lens into the eye. Patients who are not able to wear glasses or contact lenses after cataract surgery can use an intraocular lens implant to improve their vision.
Different types of intraocular lenses have different pros and cons. One type is a monofocal lens, which is designed to improve distance vision while another is a multifocal lens. Multifocal lenses can improve both distance and close-up vision. However, these devices are not as flexible as their monofocal counterparts and may take a few months to adapt to the new lenses. Furthermore, they may cause halos around lights.
One study of secondary IOL implantation found a statistically significant improvement in BCVA in 46 of 70 eyes. The BCVA of none of the eyes was worse than the logMAR line after secondary IOL implantation. In addition, no eye lost its line of BCVA after secondary IOL implantation.
Toric IOL implantation
The implantation of toric intraocular lenses has a number of key features that should be considered before the procedure begins. The initial surgical site must be properly prepared to ensure that the IOL is secure in the eye. The surgeon should mark the steep axis of the lens using a degree gauge. He should also review his preoperative notes to ensure that the steep axis has been appropriately marked on the toric IOL. Once the eye is properly prepared for the procedure, the surgeon will inject a viscoelastic device into the capsular bag and rotate the IOL into its final position. During this rotation, the surgeon may use a second instrument to secure the IOL in place. This allows a gentle nudge to hold the IOL in place and minimize the incidence of postoperative rotation.
Toric IOL implantation requires the careful optimization of all steps. A single measurement can result in a small percentage error. The newer technology for toric IOL implantation is expected to improve the accuracy of the procedure. The use of intraoperative aberrometry can be a major benefit in toric IOL implantation, as it provides real-time feedback and allows surgeons to optimize the axes of the toric IOL.
AddOn secondary IOL implantation
There are several factors that contribute to the safety and success of an AddOn secondary IOL implantation. These factors include the reversibility of the surgery and the depth of the anterior chamber. A post-PK patient with a shallow anterior chamber may be at increased risk of complications. However, the addition of an AddOn lens may improve visual acuity in such patients.
The AddOn Sulcus-based A4SW00 neutral power aspheric monofocal IOL manufactured by Medicalontur, Hungary, is well-suited for secondary IOL implantation. The implantable IOL is designed to reduce lens opacification and is 25% water content. It is also easily implantable. After implantation, the patient undergoes an ocular examination and a slit-lamp examination.
The AddOn(r) secondary IOL has a convex-concave optic design and is designed for implantation in the ciliary sulcus. The convex-concave shape of the implanted device helps prevent touch between the lens and the iris, reducing the risk of iris chafing. The AddOn is available in monofocal, toric, or multifocal designs.
Non-diffractive/non-multifocal IOL implantation
Non-diffractive/nonmultifocal IOL implantation is an excellent option for patients with myopia, astigmatism, or a combination of these conditions. A non-diffractive lens may correct these problems while simultaneously reducing glare and achieving spectacle independence at intermediate and far distances. However, non-diffractive lenses may have disadvantages.
A non-diffractive/non-diffractive IOL is a lens implanted in one eye for near vision and a monofocal IOL for distance vision. This type of IOL is generally not suitable for patients who already have cataracts. Patients should discuss these considerations with their eye doctors and choose the best option for them.
The first major difference between multifocal and non-diffractive IOLs is the shape of the lens. Multifocal IOLs are more advanced and feature more than one focal point. They can be further subdivided into refractive and diffractive types. A diffractive IOL, such as ReSTOR (Alcon), has steps that bend incoming light differently. These steps produce a near-focus while the remaining portion of the lens is a refractive lens.