For patients entering the age of presbyopia onset, the effect of loss of accommodation on their ability to function will eventually be insurmountable. Some are content wearing glasses or contact lenses; others turn to us for surgical intervention. Most patients who seek treatment at the Carones Ophthalmology Center in Milan, Italy, will walk out with a prebyopia-correcting IOL—approximately 90%, to be more exact.
SELECTING THE IOL
I perform intraocular presbyopia correction because the postoperative outcomes in the majority of patients are better than those with corneal refractive procedures targeted to correct presbyopia. The secret to achieving these superior outcomes is choosing the right lens for the right patient. This may be done based on the patient's characteristics, including expectations, visual preferences, and lifestyle. The individual needs of our patients are too diverse to use one lens across all cases.
After dialogue with the patient, I end up selecting a multifocal IOL in 90% of intraocular presbyopic cases that I treat. My first and foremost target is patient satisfaction, and I believe that the multifocal IOL achieves this target in patients who do not have unnecessarily high demands and who are willing to use spectacles in certain circumstances, such as night driving and reading in dim light. I always tell any candidate for multifocal IOLs that this lens is a wonderful device for providing some spectacle freedom, and I emphasize that 100% spectacle independence should not be expected.
If the patient agrees to these parameters, it is safe for me to select a multifocal IOL for presbyopia correction. Using the newest generation of multifocal IOLs, there is a lower incidence of night vision symptoms than with previous generations. These improvements help surgeons to promote the use of the latest multifocal IOL models.
It is perhaps easier to describe the worst candidates for multifocal implants than it is to describe the best candidates. Patients who are myopic before cataract or refractive surgery are very demanding with regard to quality of near vision. The worst case that I treated was a patient who was -4.00 D and able to read in poor lighting conditions preoperatively. I implanted a multifocal IOL and the outcome was disastrous; he was not happy because even though he was independent of spectacles, the quality of near vision with the multifocal IOL was not (and never will be) comparable with the quality of vision that the patient had as a myope preoperatively.
I also feel strongly about avoiding the use of multifocal IOLs in patients whom I deem complex cases, such as those with significant astigmatism, dry eye, or inadequate tear film production. I have found that these patients often complain of poor quality of vision postoperatively.
REFRACTIVE LENS EXCHANGE
Refractive lens exchange (RLE) is a possible solution for presbyopia if it is accompanied by other refractive errors, but I will not perform it in plano patients. The best candidates in these cases are approximately 40 or 42 years of age, with significant hyperopia (approximately 4.00 D). Their accommodation has deteriorated, and they will usually do anything to gain spectacle independence. I also perform RLE in patients with significant myopia; however, I am more timid with patient selection and prefer to treat patients over age 50 years.
Outcomes of RLE and cataract surgery are similarly positive. The difference in patient satisfaction lies in these patients' reasons for undergoing surgery. The patient with significant cataract that reduces quality of vision or BCVA is easier to manage because he is less demanding. The RLE patient is difficult to manage with regard to multifocal vision. This patient requires more chair time, more descriptive explanations, and more time invested postoperatively.
There is always the potential need for retreatment, and so I make it a rule to discuss enhancements with the patient preoperatively. I tell the patient that, even if he is a perfect candidate for surgery, there is still the possibility of need for enhancement. We know that approximately 10% of patients will need an enhancement. During the preoperative consultation, I offer the patient a refractive package in which the price of the touch-up is already included. I do not promote it, but I do disclose it before the implantation.
I no longer use limbal relaxing incisions because, at least in my hands, the procedure is more unpredictable than astigmatism correction with the laser. I like to steer the final astigmatic outcome with laser surgery.
I think that multifocal IOLs are the best solution available today for presbyopia correction. However, 5 years from now I hope to see truly accommodating IOLs—perhaps using a gel technology to fill the capsular bag. I also hope to see an increase in the use of piggybacking multifocal IOLs to fix presbyopia in patients who already have a multifocal implant. Until then, surgeons can continue—or begin—using the latest generation of multifocal IOLs.
For those surgeons willing to transition from purely monofocal cataract or refractive procedures to presbyopiacorrecting IOLs, the best advice I can give you is: Practice conservative patient selection. Develop your technique on the best candidates and garner the experience you need to extend indications to harder cases. The most important consideration is providing each patient with the technology that is right for him.
Francesco Carones, MD, is the Cofounder and Medical Director of the Carones Ophthalmology Center, Milan, Italy. Dr. Carones states that he is a paid consultant to Alcon Laboratories, Inc. He is a member of the CRST Europe Editorial Board. Dr. Carones may be reached at tel: +39 02 76318174; e-mail: email@example.com.