In most European countries, refractive cataract surgery / lens exchange is attracting more and more patients, despite the fact that it is not covered by state insurances and therefore comes at a cost for the patient or for private insurance companies. It frequently involves the implantation of multifocal IOLs, namely trifocal, after the success of this lens design. With refractive cataract surgery / lens exchange we can virtually obtain spectacle independency for our patients, sometimes at the cost of pseudophakic Lasik to correct for residual refractive errors. In my practice, this is the case in 2-3% of the operated patients.
Spectacle independency is of value in contemporary society. Spectacles reduce the potential activity in many working conditions—for example in my patients who use two computers with different sizes, distances, and visual angles. In other conditions, spectacles may impede the workers activity or may reduce safety, as many warning signals are written in small print that can be difficult to read with spectacles. Sometimes a warning message is sent by phone, and we are supposed to read it and to act accordingly without delay. Spectacle independency improves our role in modern society, and especially in high myopia or in low to medium hyperopia, the conditions that benefit more from refractive lens exchange.
For these reasons, the age of the patients who ask for surgery is decreasing. From a medium age of 70 y for cataract surgery, I recorded a medium age of 62 y for refractive cataract surgery / lens exchange. These patients are still active at work, and in many instances ask for spectacle independency to improve their working ability and not for cosmetic reasons.
Refractive cataract surgery / lens exchange is now my preferred method to help those patients. There are a number of reasons that make this approach so attractive.
1. The availability of diffractive trifocal IOLs offers a substantial improvement over the bifocals. They refract the incoming light better and reduce the
“lost” light to less than 15% in the
first models, and to less than 10% in the latest models. This improves the intermediate vision and reduces the confounding halo, thus increasing contrast sensitivity in the implanted patients.
2. The evolution of the diffractive design comes from improvements
in engineering, with the consequent reduction of the starburst phenomena frequently mentioned by patients during the first months of use.
3. The availability of Toric Trifocal IOLs, considering both the pre-implant technology that is available and the postoperative possible rotation of the IOL to improve the results.
4. The release of advanced IOL power calculation formulas. Current formulas are by far more precise than those of 15-20 years ago and reduce residual refractive errors to a minimum. However, I always talk about postoperative refractive error and the possibility of a laser treatment for the best results.
5. The improved safety of lens surgery, mainly deriving from the ESCRS – Peter Barry’s endophthalmitis study that taught us how to reduce infection to about 1 out of 12,000 cases. In another study, the ESCRS group led by our current President Rudy Nujits demonstrated the virtual defeat of a known complication of the surgery – cystoid macular edema.
6. The long-lasting results of the surgery. The refractive result obtained through IOL implantation will last for a long time, virtually for the remaining life of the subject. Against-the-rule astigmatism may interfere with the achieved emmetropia later on, but with many years of delay. And we already have piggyback toric IOLs to correct for it.
7. The still inconsistent results of presbylasik. Presbylasik is especially effective in low hyperopia with little astigmatism in patients in their late forties, but the result still depends
on a personal factor, the residual accommodation. In addition, presbylasik changes the central part of the cornea and it may jeopardize the subsequent implantation of a multifocal IOL.
8. The general knowledge and acceptance of lens surgery mean it is more familiar to the patients than other forms of ocular surgery. A procedure so frequently performed looks safer and easier to them, despite this not being the case.
9. The quick recovery time. Lens surgery usually requires only 2-3 days of rest before the patient goes back to his normal activities, and only one week of postoperative therapy.
10. The availability of simultaneous bilateral surgery, which is now normally accepted even in public hospitals in Italy. This requires a specific informed consent and protocol.
11. The potential to operate post- lasik patients. Lasik patients are accustomed to unaided vision, and they want to continue with their spectacle independency as they come of age. The current power calculation formulas work well; however, I always make sure to have enough corneal thickness for a touch-up procedure.
12. The availability of Lasik to correct for residual refractive errors. My percentage of pseudophakic Lasik is below 3%, and including previously operated corneas.
All these advantages favour refractive cataract surgery / Lens exchange as my preferred refractive surgery in patients over 50, but we should not forget this is a surgical procedure with potential complications that must always be told to any patient.
a. Risk for retinal detachment.
Although no report of increased risk has been published in emmetropic or hyperopic patients, the risk is real for high myopic patients. We can anticipate an incidence of 1% per year, and myopic patients should know this.
b. Increased dry eye symptoms are a common finding in the pseudophakia. There is suspicion this comes from the use of povidone iodine to disinfect the conjunctiva, or from the use of antibiotics after surgery.
c. Posterior capsular opacification. This will be solved by Nd:YAG lase application, but patients may think this is a failure of surgery. It is better to discuss PCO with them and proceed to early YAG laser capsulotomy.
d. Inability to read small print. This is for stock exchange quotations. We should instruct the patient to correct for near focus of the IOL. Plus 1 D add is not enough, we must employ plus 3 D add.
e. Night halo and starburst will be perceived with any diffractive IOL and might not be accepted by some patient. We should tell opticians, engineers, photographers, and heavy night drivers about this.
f. Change in colour vision. This will depend on the refractive index of the IOL material, which determines the Abbe number.
g. Macular degeneration. Only hard drusen are allowed. However, the negative impact of the diffractive optics on vision in an eye with macular degeneration will always be minimal.
Balancing all the factors of refractive cataract surgery / lens exchange will produce a suggestion for each specific patient. My experience is very positive: after six years and more than 500 patients, I explanted only one because of night glare, and my success includes one engineer with -3.0 D of myopia, one patient after presbylasik, and several monocular patients. After more than 30 years of multifocal IOL implantation, and after 6 years of trifocal IOL implantation, I implant trifocal IOL as routine. Patient selection is reverted, selecting patients for monofocal IOLs when multifocals are contra- or less indicated like in severe macular degeneration, in extreme myopia, in advanced glaucoma. Refractive cataract surgery / Lens exchange is getting a social value in developed countries: it keeps vision in shape, and helps patients in keeping an active role in the society. We, as ophthalmic surgeons, can be proud of this vision improvement.