Wavescan-Guided Bilateral Multifocal Surface Ablation
Presbyopia is the age-related loss of accommodation due to lenticular or extralenticular changes, affecting 100% of the population older than 40 years. The Advanced CustomVue aspheric hyperopic presbyopia procedure (Advanced Medical Optics, Inc./Visx, Santa Ana, California, and Santa Clara, California, respectively) is a patented omnifocal aspheric profile that treats the central zone with pupil-dependent central steepening. It accounts for intermediate and near function, while the peripheral zone corrects for distance vision. The combination of a pupil-size–dependent central zone and the LASIK flap produces an aspheric curve that expands the depth of focus.
The Visx aspherical ablation profile features Variable Spot Scanning technology (Advanced Medical Optics, Inc./Visx) to create subtle ablation shape change to a patient's wavefront map. The Visx asperical presbyopic shape for surface ablation treatments is currently investigational. When combined with Advanced CustomVue, the central zone is steepened to provide near vision, and the peripheral zone is targeted for distance vision. My colleagues and I undertook a study to determine whether surface ablation using the same nomogram could compare with the results of Jackson et al.1
This US Federal Drug Administration study—approved by Health and Welfare Canada and the Western Institutional Review board—was based at one center (ie, London Place Eye Centre, in Vancouver, Canada), where I performed aspheric hyperopic presbyopic surface ablation in 30 patients (60 eyes). Sixteen male patients and 14 female patients ranged in age from 46 years to 61 years (52 ±4 years) and had the following preoperative refractions: preoperative sphere ranged from plano to 2.75 D (1.27 ±0.56 D), and cylinder ranged from plano to 1.00 D (0.37D ±0.28 D).
All patients underwent aspheric hyperopic presbyopic surface ablation treatments with no nomogram or physician adjustments. Iris Registration—used in all patients during this study—is a critically important component in presbyopia treatments, because it ensures proper registration of wavefront-guided ablation and proper placement of the pupil-size–dependent central zone that is relative to the pupil centroid (Figure 1). At 3 months follow-up, data from 60 eyes was available; at 6 months, eight eyes were lost to follow-up.
The surface ablation treatment procedure involved (1) epithelial removal with an Amoils brush, (2) irrigation of the cornea with chilled balanced saline solution after ablation, (3) application of a soft bandage contact lens until reepithelialization, (4) and use of eye shields while sleeping during the first week after surgery. The medication regimen consisted of postoperative topical treatment with the fourth generation fluoroquinolone gatifloxacin (Zymar; Allergan, Inc., Irvine, California), an NASID (diclofenac, Voltaren; Novartis Ophthalmics, Inc., Duluth, Georgia), and fluorometholone ophthalmic ointment (FML; Allergan, Inc.). Oral analgesics and artificial tears were prescribed as needed. Additionally, patients began oral vitamin C doses 2 weeks before surgery and continued taking vitamin C doses 9 months postoperatively.
Similar to the results reported by Jackson et al, the outcomes from follow-up visits at 1, 3, and 6 months in our study showed that uncorrected distance visual acuity and uncorrected near visual acuity outcomes continued to improve over time.
Results from the 6-month visit showed that monocular uncorrected distance visual acuity (Figure 2) was 20/20 or better in 44% of eyes and 20/25 or better in 77% of eyes. Preoperatively, only 5% of patients had 20/20 vision; only 17% achieved 20/25 or better monocular uncorrected distance visual acuity. In binocular testing, uncorrected distance visual acuity was 20/20 or better before surgery in 17% of eyes, compared with 85% of eyes at 6 months (Figure 3).
For monocular uncorrected near visual acuity, no patient was able to read J3 preoperatively, however, 85% of eyes achieved that outcome at 6 months (Figure 4). The proportion of eyes with J3 or better near vision in binocular testing was only 3% preoperatively, and 98% at 6 months after surgery (Figure 5). No eye had lost more than two lines of BCVA at distance or near at 6 months. Patients were initially myopic after surgery (manifest refractive spherical equivalent, -0.93 ±0.65 D at 1 month), but it slowly regressed to -0.16 ±0.63 D at 6 months, where it remained stable.
The overall satisfaction with distance vision was calculated among the patient population through use of a questionnaire. Patients were evaluated for satisfaction with their best corrected distance vision and best uncorrected distance vision. Results showed that patients were generally satisfied with their uncorrected distance vision. The questionnaire showed that the 77% of patients were satisfied with their 6 month overall distance vision, compared with 57% who were satisfied with their preoperative level. Furthermore, preoperative and postoperative near vision and overall vision satisfaction followed suit (81% vs 30% and 83% vs 37%, respectively).
Along with my colleagues, I have found that Advanced CustomVue aspheric hyperopic presbyopia appears to be a safe and effective procedure for 40-year-old to 60-year-old hyperopes. The early postoperative results showed positive outcomes, and patients have reported high satisfaction rates with their uncorrected vision for both distance and near at all postoperative visits. No eye lost more than two lines of best corrected distance and near vision at 6 months. Follow-up is ongoing.
D. Keith Williams, MD, FRCSC, FACS, FRCOphth, practices at the London Place Eye Centre, in Vancouver, Canada. Dr. Williams states that he is a paid consultant to Advanced Medical Optics, Inc./Visx. He may be reached at telephone: +1 604 526 2020; fax: +1 604 688 5211; or dkwident@telus.net.
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