What is EVO?
EVO is a refractive lens also known as a phakic IOL. “Phakic” meaning that the natural lens of the eye is in place, and “IOL” meaning intraocular lens, or a lens inside the eye. The EVO is a posterior chamber implant that is situated through a small incision in the eye behind the iris (the coloured part of the eye), and in front of the natural crystalline lens in order to improve your near-sightedness, farsightedness or astigmatism.
What and Who is EVO intended for?
EVO surgery is intended to safely and effectively correct near-sightedness (-0.5 to -18.0 dioptres (D)), the reduction of near-sightedness in patients with up to -20 dioptres (D) of near-sightedness, treatment of astigmatism from +0.5D to +6D and and correction of farsightedness from 0.5 to 10.0D. It is indicated for patients who are at least 21 years of age.
In order to be sure that your surgeon will use an EVO lens with the most adequate power for your eye, your near-sightedness should be stable for at least a year before undergoing eye surgery.
The EVO represents an alternative to other refractive surgeries including laser assisted in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), other laser vision correction procedures, incisional surgeries or other means to correct myopia such as contact lenses and eye glasses.
Who should not have the EVO procedure?
Patients who are pregnant and nursing and patients with a narrow angle in the front chamber of their eye, because in this case the space for the EVO lens would be too small. The patient education booklet provides an additional list of conditions that should be taken into consideration when making a decision about the EVO procedure.
What is the key potential benefit of EVO?
The key benefit of EVO surgery is the permanent correction or reduction of your near-sightedness, farsightedness or astigmatism allowing you to see clearly without eyeglasses or contact lenses or reduce your dependence upon them. In addition to the improvement of your uncorrected vision (vision without eyeglasses or contact lenses), your best corrected vision (best vision with contact lenses/eye glasses) may be improved.
What is EVO made of?
The material is called Collamer® , a collagen co-polymer that contains a small amount of purified collagen which is proprietary to STAAR Surgical; the remainder is made of a similar material to that found in soft contact lenses. It is very biocompatible (does not cause a reaction inside the eye) and stable. It also contains an ultraviolet light filter.
Can EVO be removed from my eye?
EVO is intended to remain in place without maintenance. The lens can be removed by your eye care professional if needed in the future. If your physician removes the lens, you will lose the benefit of your vision correction.
Is the EVO lens visible to others?
No. EVO is positioned behind the iris (the coloured part of the eye), where it is invisible to both you and others. Only your eye care practitioner will be able to tell that vision correction has taken place.
Will I be able to feel the EVO lens once it’s in place?
EVO is not typically noticeable after it is implanted. It does not attach to any structures within the eye and does not move around once in place.
What is involved in the EVO procedure?
The EVO surgery is performed on an outpatient basis which means that the patient has surgery and leaves the same day. The procedure itself usually takes 20-30 minutes or less. The patient will need someone to drive them home on surgery day. A light, topical or local anaesthetic is administered. There is very little discomfort during or after surgery. Some eye drops or medication may be prescribed and a visit with your eye care professional is usually scheduled the day after surgery.
What are the key points to remember?
Follow all of your eye care professional’s instructions before and after implantation of the EVO lens. Take any prescribed medication and schedule all recommended follow-up visits with your eye care professional, usually on an annual basis after the healing of the surgery. Contact your eye care professional immediately if you should experience a problem.