Iris clip lenses, also known as iris-fixated lenses, are a type of intraocular lens (IOL) designed to be attached to the iris. They are used to correct aphakia (absence of the natural lens) or to provide refractive correction in cases of high myopia or hyperopia. These lenses can be used when a posterior chamber lens is not suitable or when additional refractive correction is needed.
Types of Iris Clip Lenses
1. Phakic Iris-Clipped Lenses:
• Implanted in front of the natural lens for refractive correction in high myopia or hyperopia.
• Example: Verisyse/Artisan lens (by Ophtec/AMO), known for its use in correcting high refractive errors.
2. Aphakic Iris-Clipped Lenses:
• Used to replace the natural lens after cataract extraction when other IOLs cannot be used.
• Example: Artisan Aphakia lens, designed for patients without a natural lens.
Key Features of Iris Clip Lenses
• Attachment to the Iris: These lenses have haptics (small arms) that clip onto the iris to hold the lens in place. This provides stability and ensures the lens remains centered.
• Material: Typically made from PMMA (polymethyl methacrylate) or other biocompatible materials to reduce the risk of inflammation or other complications.
• Reversible: These lenses can often be removed or replaced if necessary, providing flexibility in managing patients’ refractive needs.
Advantages
• Stable Fixation: The clipping mechanism provides secure fixation and reduces the risk of lens displacement.
• High Degree of Correction: Effective in correcting high levels of myopia or hyperopia.
• Versatility: Can be used in both phakic and aphakic eyes.
Disadvantages
• Surgical Complexity: The implantation procedure is technically demanding and requires a skilled surgeon.
• Potential for Complications: There can be risks such as endothelial cell loss, pigment dispersion, and potential for increased intraocular pressure.
• Pupil Size Considerations: The size of the pupil can affect the positioning and effectiveness of the lens.
Examples of Iris Clip Lenses
1. Artisan/Verisyse Phakic IOL:
• Used primarily for refractive correction in patients with high myopia or hyperopia.
• Available in versions for both myopic and hyperopic corrections.
2. Artisan Aphakia IOL:
• Designed for aphakic patients who require a secondary lens implantation.
• Provides stable fixation by clipping onto the iris.
3. Veriflex IOL:
• A foldable version of the Verisyse lens, offering the advantage of smaller incision surgery.
Consultation with an Eye Care Professional
Selecting the appropriate iris clip lens and ensuring successful implantation requires a thorough evaluation by an experienced ophthalmologist. They will consider factors such as the patient’s ocular anatomy, visual needs, and any potential risk factors.
In summary, iris clip lenses are a valuable option for certain patients with specific refractive needs or anatomical challenges, providing stable and effective correction with careful surgical planning and execution.