Presbyopia is among the most frequently discussed topics in refractive surgery, generating curiosity and interest worldwide among surgeons and industry. Several treatment options, including conductive keratoplasty, monovision, scleral expansion, multifocal and accommodating IOLs, and presby-LASIK, aim to generate pseudoaccommodation—or artificial accommodation generated by a device or procedure.
There are two basic methods of pseudoaccommodation: intraocular, via the implantation of a multifocal or accommodating IOL and corneal, via multifocal ablation. The latter corrects the visual defect for distance and reduces near spectacle dependency,1,2 and it is the basis for presby-LASIK.
First-generation presby-LASIK procedures achieved multifocality based on refractive data only. These procedures were empirical and intuitive; the surgeon could perform either central hyperpositive multifocality (ie, central presby-LASIK)3 or peripheral hyperpositive multifocality (ie, peripheral presby-LASIK).4 Second-generation presby-LASIK procedure have improved the accuracy and predictability of the initial procedures. Ablation profiles are now based on corneal geometry and wavefront data.
It is better to use second-generation presby-LASIK techniques, such as PresbyMax, patented by Vissum Alicante (Spain) because visual and refractive outcomes have been optimized. In collaboration with the University of Alicante, our research team developed a propagation algorithm, based on Gaussian optics, that simultaneously accounts for every refractive surface.5 Using the algorithm, we evaluated and predicted the potential postoperative optical quality in eyes that underwent central presby-LASIK ablations.5 Predictability was excellent, with a strong and significant correlation between UCVA measured and calculated after presby-LASIK. Central presby-LASIK provided good intermediate and distance visual acuity for a 5-mm pupil. Additionally, no significant differences in near and distance visual acuity were found between central presby-LASIK and simulated intraocular pseudoaccommodation with the Array multifocal IOL (no longer available; Advanced Medical Optics, Inc., Santa Ana, California) using the Alicante model.6
PresbyMax designs the multifocal ablation profile according to the predicted postoperative outcomes for far and near distances. We use the Esiris laser (Schwind eye-tech-solutions, Kleinostheim, Germany). As in any other central presby-LASIK technique, a central area is created for near vision and a peripheral area for distance vision. Multifocality, created with biaspheric ablation profiles based on optimized mathematic curves, provides adequate transitions between far and near vision.
INDICATIONS FOR TREATMENT
PresbyMax provides a near vision add of between 1.75 and 3.00 D. It results in good near and far vision quality, and it compensates for age-related positive asphericity. Hyperopic and myopic patients are eligible for the procedure. The patient should have a spherical equivalent of no more than 4.00 D, astigmatism of no more than 2.00 D, near visual acuity of J2 or J1 with a near add of 1.50, corneal topography with no signs of keratoconus or irregular astigmatism, no dry eye syndrome, and pachymetry of at least 500 µm.
In addition to adequate patient selection, the following are other considerations for PresbyMax: The flap must have a planar configuration; an adequate point, preferably the corneal vertex, for ablation centration should be selected; and the preoperative corneal asphericity should allow the required induction of spherical aberration, thus providing depth of focus.
Excellent visual and refractive outcomes were obtained at 3 months for myopes (n=20 eyes) and hyperopes (n=20 eyes). A total of 70% of hyperopic eyes and 100% of myopic eyes achieved a monocular distance UCVA of at least 0.8. A monocular near UCVA of J3 or better was seen in 80% of hyperopic and 100% of myopic eyes. Regarding binocular results, a distance UCVA of at least 0.8 was seen in 80% and 100% of hyperopic and myopic eyes, respectively. All the evaluated patients achieved a binocular UCVA of at least J3.
Two eyes that underwent hyperopic presby-LASIK lost up to one line of far BCVA. No lines of BCVA were lost in the myopic eyes. The mean postoperative spherical equivalent was -0.26 ±0.40 D, with 90.6% of eyes having a spherical equivalent within ±0.50 D. Figures 1 and 2 are topographies from two patients who underwent PresbyMax.
PresbyMax is a promising surgical alternative for the correction of presbyopia, initiating the second generation of presbyLASIK techniques. PresbyMax is the first systematic and scientifically based approach for the correction of presbyopia with an excimer laser. It is an excellent option for the compensation of initial and intermediate presbyopia in patients with spherical equivalent between 4.00 and -4.00 D. The use of a mathematical model for predicting postoperative outcomes avoids contrandications of presby-LASIK that may lead to visual acuity problems postoperatively.
Jorge L. Alió, MD, PhD, is a Professor and the Chairman of Ophthalmology at the Miguel Hern‡ndez University, Alicante, Spain, and the Medical Director of Vissum Corp., Spain. Professor Alió states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +34 96 515 00 25; e-mail: firstname.lastname@example.org.
David P. Piñero, PhD, practices at the Vissum Corp., Instituto Oftalmológico de Alicante, Spain. Dr. Piñero states that he has no financial interest in the products or companies mentioned. He may be reached at e-mail: email@example.com.
- Becker KA, Jacksche A, Holz FG. PresbyLASIK: treatment approaches with the excimer laser. Ophthalmologe. 2006;103:667-672.
- Telandro A. Pseudo-accommodative cornea: a new concept for correction of presbyopia. J Refract Surg. 2004;20:S714-17.
- Alió JL, Chaubard JJ, Caliz A, Sala E, Patel S. Correction of presbyopia by Technovision central multifocal LASIK (presbyLASIK). J Refract Surg. 2006;22:453-460.
- Pinelli R, Ortiz D, Simonetto A, Bacchi C, Sala E, Alió JL. Correction of presbyopia in hyperopia with a center-distance, paracentral-near technique using the Technolas 217z platform. J Refract Surg. 2008;24:494-500.
- Ortiz D, Alió JL, Illueca C, et al. Optical analysis of presbyLASIK treatment by a light propagation algorithm. J Refract Surg. 2007;23:39-44.
- Illueca C, Alió JL, Mas D, et al. Pseudoaccommodation and visual acuity with Technovision presbyLASIK and a theoretical simulated Array multifocal intraocular lens. J Refract Surg. 2008;24:344-349.