The treatment of presbyopia is one of the most challenging frontiers of ophthalmic surgery. Even with a plethora of corrective options, the goal of restoring accommodation seems to be elusive. In Germany, the percentage of patients with presbyopic symptoms has increased significantly due to the aging of the population, and this trend will continue over the next few years. Another factor is that patients are more demanding and ask for more options than just reading glasses or multifocal contact lenses. Accordingly, the number of patients who elect surgery for presbyopia correction is on the rise. Today, about 10% of our patients undergo presbyopia correction at the Augenklinik Bellevue.
For successful surgical treatment of presbyopia, it is important to conduct thorough patient evaluation and patient counseling in advance of the procedure. Understanding the patient’s expectations is especially crucial, as unrealistic expectations can lead to an unhappy patient postoperatively. Clinical diagnostics including corneal topography, aberrometry, pupillometry, and an optical coherence tomography (OCT) scan of the macula are mandatory. Macular puckers are often present in the eyes of elderly patients, making OCT a must-have assessment before every lens surgery.
CORNEA- AND LENS-BASED OPTIONS
At the Augenklinik Bellevue, we feel that both corneaand lens-based options can be appropriate for presbyopia correction. At the moment, our strategy of choice is multifocal IOL implantation. In patients with excessive corneal aberrations, however, we prefer using a monovision approach. Other treatment options such as corneal inlays and scleral-expanding systems are alternatives.
Any method of presbyopia correction has limitations. In multifocal IOL implantation, there are the associated risks of intraocular surgery, including endophthalmitis. Additionally, not all patients are willing to undergo intraocular surgery if other options, such as monovision LASIK or presbyopic LASIK (presby-LASIK), are available.
We have performed simultaneous correction of presbyopia and ametropia using PresbyMax, a biaspheric presby-LASIK technique in which we shape the central cornea for near vision and leave the midperipheral cornea for far vision. PresbyMax is performed with the Amaris 750 (Schwind eye-tech-solutions). Initially we treated both eyes with the same ablation profile for near addition, but we subsequently changed to a monovision strategy to improve results for binocular distance visual acuity, still using a multifocal ablation profile for both eyes.
We have seen good results with this technique in both hyperopes and myopes. We do not use PresbyMax in near emmetropic patients, and in moderately myopic patients we prefer classical monovision with an aberration-free ablation profile. Younger presbyopic patients usually do well with PresbyMax, but the procedure can also be repeated when presbyopia progresses.
A multifocal contact lens trial is helpful in making the final decision. If the patient does not tolerate multifocality during the trial, PresbyMax is not an option.
MULTIFOCAL IOL IMPLANTATION
When implanting multifocal IOLs to treat presbyopia, we use bifocal and trifocal models. We have had good results with the trifocal AT.LISA (Carl Zeiss Meditec) and FineVision (PhysIOL) lenses. Since integrating them into practice, the percentage of bifocal multifocal IOLs we implant has decreased. One reason for the apparent preference for trifocal lenses is that they provide the best intermediate visual acuity, which in our world of smartphones and computer work is the biggest factor in favor of these lenses.
In the presence of 1.00 D or more of astigmatism, the AT.LISA toric is implanted. The availability of toric multifocal IOLs has allowed us to decrease the number of bioptics procedures and touch-ups we perform. The toric Mplus (Oculentis GmbH), with its individualized torus, is easy to implant because rotation of the lens into the steep axis is not necessary.
Because of the possibility for photopic and night driving problems that can occur with all multifocal IOLs, we also have the Mplus and Mplus comfort (Oculentis GmbH) in our portfolio. These lenses provide high levels of patient satisfaction, due to their good results in contrast sensitivity and reduction of glare and halos. When patients are interested in good intermediate visual acuity and have no objection to using glasses for extended reading, the Mplus comfort with its 1.50 D of near addition is our first choice. Historically, mix-and-match strategies have not been our choice, but we are considering this approach with the Mplus and the Mplus comfort after hearing of the impressive results of colleagues including Sunil Shah, MBBS, FRCOphth, FRCS(Ed), FBCLA.
An interesting option in pseudophakic patients who want to reduce their spectacle dependence is multifocal supplementary IOLs for sulcus implantation. We use a diffractive model, the AddOn IOL (1stQ), which provides good centration due to its four flexible haptics. This lens has a near addition of 3.50 D and is available in spherical powers from -3.00 to 4.00 D. Unilateral implantation is often sufficient to provide adequate near vision.
The refractive model of the AddOn lens is used to create standard monovision; however, we prefer the diffractive version. We have seen no postoperative problems such as pigment dispersion or secondary glaucoma after implantation. The multifocal AddOn IOL has enormous potential, but, given that the lens works best in elderly pseudophakic patients, marketing is difficult.
PROCEDURES THAT HAVE CAUGHT OUR ATTENTION
The next presbyopia-treatment option we want to try is the Raindrop Near Vision inlay (Revision Optics, Inc). We are intrigued by this corneal inlay because it has a similar optical concept to PresbyMax, which is steepening of the central cornea. Also, reversibility is an added bonus. Nevertheless, we are skeptical of corneal implants because of potential associated complications including corneal scarring.
We are also highly interested in the effect of limbal relaxing incisions (LRIs) on our refractive results with multifocal IOLs. We have been performing laser-assisted cataract surgery with the Lensar Laser System (Lensar, Inc.) since August 2013. We also create LRIs with this platform in patients with 1.50 D or less of astigmatism in the hopes of reducing residual postoperative refractive error and further improving UCVA (Figure 1). To achieve this goal, however, we must create our own nomograms after longer follow-up.
It is likely that other options for presbyopia treatment will be born from the use of femtosecond laser technology, if studies on lens softening to increase accommodation are successful. This would be a great step forward in presbyopia correction because it is a noninvasive technique treating the cause of presbyopia—the loss of elasticity of the human lens. Nevertheless, there are many good solutions now available to treat presbyopic symptoms in our patients, even though they all represent a reasonable compromise.
Because all of our presbyopiacorrecting procedures come with compromises, it is not surprising that some outcomes are less favorable than others. Below I recount two cases, of which one had a rather negative outcome and one a positive outcome.
Case No. 1: Capsular fibrosis. A 55-year-old woman with hyperopic astigmatism and presbyopia was treated bilaterally with implantation of toric bifocal plate-haptic IOLs. In both eyes, a capsular tension ring (CTR) was implanted. Intraoperatively, no complications occurred. On day 1 postoperative, near UCVA was reading acuity determination (logRAD) 0.0, and distance UCVA was logMAR 0.1 in both eyes.
Six weeks later, the patient presented with severe loss of visual acuity at all distances in both eyes due to massive capsular phimosis (Figure 2). In the left eye, Nd:YAG laser capsulotomy was successful in opening the fibrosis. In the other eye, however, surgical excision was required. Moderate rotation of the lens position in both eyes led to 0.75 D of induced astigmatism, and there was a hyperopic shift of 1.50 D in the right eye and 1.75 D in the left. We prescribed glasses for distance vision, which made the patient relatively satisfied with distance BCVA of logMAR 0.2 and near BCVA of logRAD 0.2. Three months later, we performed a LASIK enhancement, resulting in UCVA of logMAR 0.1 and logRAD 0.2.
From this case, we learned that capsular fibrosis, even in the presence of a CTR, can cause massive problems in multifocal IOL patients. Surgeons implanting multifocal IOLs must be able to handle these difficult situations and be able to offer the patient a touch-up laser treatment.
Case No. 2: Mild amblyopia. A 61-year-old presbyopic patient with hyperopic astigmatism and mild amblyopia due to anisometropia inquired about presbyopia correction. She declined intraocular surgery. Her refraction was +5.00 -3.00 X 180º in the amblyopic eye and +2.00 -1.00 X 70º in the fellow eye, and visual acuity in these eyes was 0.5 and 1.0, respectively. Her near addition was 2.50 D. PresbyMax treatment was planned using a micro-monovision approach. Postoperatively, her distance UCVA was 0.5 and 1.0—the same as her preoperative BCVA—and her near UCVA was 0.9 (Figure 3).
What we learned from this case is that PresbyMax can be used to simultaneously correct hyperopic astigmatism of up to 5.00 D and presbyopia. Mild amblyopia in our opinion is not a contraindication for a multifocal presbyopia-correcting approach with multifocal IOLs or PresbyMax.
Detlef Holland, MD, is a cataract and refractive surgeon at the Augenklinik Bellevue, Kiel, Germany. Dr. Holland states that he has no financial interest in the products or companies mentioned. He may be reached at e-mail: firstname.lastname@example.org.