Correction of presbyopia accounts for approximately 10% to 15% of procedures I perform in my practice. Over the years, I have used a number of presbyopia-correction techniques, including corneal inlays such as the Kamra (AcuFocus, Inc.) and Raindrop Near Vision Inlay (Revision Optics); multifocal IOL implantation; and monovision excimer laser surgery.
MANY OPTIONS AVAILABLE
Generally, I prefer a lens-based approach to presbyopia correction: specifically, implantation of multifocal IOLs. Multifocal IOL technologies have undergone many positive improvements in recent years, leading to minimal or reduced incidence of undesirable side effects. Furthermore, the procedure is reversible. Multifocal IOLs can be implanted after clear lens extraction or during cataract surgery. In recent years, with the introduction of femtosecond laser cataract surgery technology, more effective IOL positioning can be achieved, leading to improved refractive results.
Multifocal IOLs, with or without a toric component, provide good long-term visual outcomes. The newest version of the ReStor platform, the AcrySof IQ ReStor +2.5 D IOL (Alcon) provides better distance and intermediate vision with less halo and scattering than previous versions. Extreme near vision, by which I mean very close distances—less than 45 cm—is less than satisfactory with this version, but it provides good enough near vision to comfortably read the time on your watch, messages on your cellphone, and stories in the newspaper without any problems. As long as we inform the patient of this preoperatively, outcomes and patient satisfaction levels will be good.
In selected cases, I prefer to use a monovision approach with excimer laser surgery. Patient selection criteria and assessment are important in presbyopia correction, and one must keep in mind that patients' neural adaptation to monovision can take some time after surgery. The advantage of the monovision approach is that, if adaptation does not occur after a period of time, the near-corrected eye can be corrected for distance vision.
For corneal inlay surgeries, patient selection criteria are more important than for lenticular surgery. Adaptation to monovision may take much longer than to multifocal IOLs. Even if patients can see very well at distance and near, they may not be completely satisfied. In this regard, corneal inlays are a safer option than corneal ablation procedures because they are reversible and easy to perform.
TAKING THE BAD WITH THE GOOD
In 8 years of performing presbyopia-correction procedures, I have performed cases that have had excellent results and fortunately few that have had notso- excellent results.
Case No. 1: Corneal inlay surgery. One that falls in the latter category was with a corneal inlay, in which the treatment did not provide the desired effect of presbyopia correction. The patient had 2.50 D of hyperopia in both eyes, and she had never in her lifetime used glasses for distance or near vision. She had read positive reviews of corneal inlays on the Internet, and she thought that this approach would solve her problem without side effects. She specifically asked me to perform an inlay operation with the excimer laser.
For any presbyopia-correction procedure—as for any surgical procedure in general—it is vital to explain every detail to the patient, in order to be sure that he or she fully understands and consents to the surgical procedure. It is crucial to allocate as much time as possible to inform the patient and to clarify information he or she may have read on the Internet or similar sources. The surgeon should not be misled or rushed to an erroneous decision by the patient's will to have a particular procedure done.
I performed the corneal inlay surgery successfully in this case. I followed the patient for 3 months, and she could see J1 at near and 20/20 at distance. Everything was great, except that she was unhappy. She thought that she could not see. The inlay was placed in only one eye, but she had complaints about both eyes. During follow-up, I found out that she was taking an antidepressant.
The preoperative evaluation is important; in fact, it is a key aspect in presbyopia treatment. I had to fully understand and comprehend the patient's desires, and unfortunately I did not correctly fathom them at that time. I had to ask the patient explicitly if she was using an antidepressant, and I learned that she had kept her medication record secret, and that specific medication was not recorded in the preoperative history.
Adaptation to monovision and adaptation to a new method of focusing are efforts that presbyopia-correction patients must cope with. Highly motivated patients with a positive attitude can adapt easily within a short time. However, it is important for the surgeon not to be misled into believing that a given patient is an ideal candidate because of a perceived highly positive and motivated cognitive and behavioral status. In this case, I think the failure was not directly related to the inlay procedure; the patient would have had the same complaints whether I had performed a monovision laser or multifocal IOL treatment instead. The lesson here is that preoperative evaluation and patient selection are very important in presbyopia-correction surgery.
Case No. 2: Clear lens extraction. Fortunately, not all cases are like Case No. 1. I performed a clear lens extraction in a 46-year-old man with BCVA of 0.9 in his right eye with a refraction of +3.50 -2.00 X 180°, and BCVA of 0.3 in his left eye with a refraction of +6.00 -2.00 X 175°. His left eye was amblyopic, and therefore it was necessary for him to achieve binocular vision postoperatively. I hesitated to recommend a multifocal toric IOL because of this. The patient was unhappy at work due to his difficult visual condition. I decided to implant an AcrySof ReStor +2.5 Toric IOL, and the patient ended up with refractions of +0.50 -0.50 X 175º in the right eye and 20/20 visual acuity and +0.25 -0.75 X 170º in the left. The reduced step heights of the diffractive zones in these multifocal IOLs provide good distance vision equivalent to a monofocal IOL with fewer unwanted visual phenomena such as halo and glare. The patient was happy with the results after surgery.
When assessing patients for presbyopia correction, the surgeon must remember that a variety of approaches are available. Many patient factors, including age, refraction, employment, ocular pathologies, and social lifestyle, must be considered in the determination of the best approach to presbyopia correction for each individual. It is a matter of the utmost importance to assess the patient correctly and provide him or her with the best solution available.
I am still hesitant to use cornea-based procedures such as inlays and multifocal corneal ablation. I look forward to lenticular technologies that will presumably improve on current technologies and offer additional advantages in the near future—pun intended.
The future does look promising, but, like our newly implanted multifocal IOL patients, we need time to adapt. The patient needs to adapt to the surgical procedure and the implanted lens or inlay. So do we physicians, especially when we have so many potential presbyopic treatment alternatives at our disposal.
Aylin Kiliç, MD, practices at Dunya Eye Hospital, Istanbul, Turkey. Dr. Kiliç states that she has no financial interest in the products or companies mentioned. She may be reached at tel: +90 212 3623232; e-mail: firstname.lastname@example.org.