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Up Front | Jan 2007

Laser Presbyopia Reversal: An Alternative Procedure

As an adaptation of anterior ciliary sclerectomy, this procedure uses an Erbium laser to excise scleral tissue.

Presbyopia is the natural loss of autofocus (ie, accommodation) that affects the majority of middle-aged individuals. Even people who have never worn spectacles have trouble reading, using a computer or cellular phone, threading a needle, applying make-up, or completing other activities that were easily performed when younger. Once a person reaches their mid-40s—as part of the eye's natural aging process—working and reading distances increase, especially at night or when tired. It becomes necessary to constantly wear and remove reading spectacles.

Twenty-first century ocular surgery promises to free us from the everlasting tie with presbyopia that, since 1300, has forced us to wear reading spectacles with little alternative. The ophthalmic benefits of presbyopic correcting alternatives are more important than the IOLs and refractive surgery procedures developed in the 1950s and 1970s for myopia.

Presbyopia reversal has a great potential for the population older than 45 years; it also has an incredible economical impact. Worldwide, more than 2 billion people have presbyopia. In the United States and Italy, respectively, 100 million and 26 million people suffer from presbyopia. Consider longer life expectancy as well as social, economical, and psychological issues: The threat of presbyopia is stronger every day, because 50-year-olds are still considered young and may feel young at heart. For this reason, our patients demand that we research the presbyopia correcting techniques for emmetropic people with clear crystalline lenses. Presbyopic treatments include monovision—a less than optimal treatment resulting in a loss of depth perception, stereoscopic binocular vision, and poor intermediate vision. The majority of patients do not accept monovision, because it does not restore bilateral physiological accommodation.

Nomograms for multifocal excimer laser treatment of presbyopia are being developed, however, several issues with this treatment are unresolved. These include nonrestoration of accommodation; poor control of postoperative corneal asphericity; potential of postoperative epithelial hyperplasia; increased depth and volume of ablation, which may trigger excessive wound healing; loss of contrast sensitivity; optical aberrations; and halos and glare. Conductive keratoplasty has produced increases of 1.00 D to 1.50 D of near vision, however, regression, optical aberrations, and cosmetic appearances remain a problem. Multifocal lenses are a choice for elderly patients who need cataract surgery, as I do not replace healthy lenses at a younger age.

I think that understanding presbyopia allows us to fight against it. The crystalline lens of the eye grows constantly at an approximate rate of 0.02 mm each year, while the sclera stops growing after puberty. Each year, the crystalline lens loses valuable space inside the sclera to change focus for varying distances. This inability to accurately focus may cause a blurred close-up focus (ie, vision at a normal reading distance) and eyestrain or fatigue during close work situations.

Presbyopia reversal should restore accommodation to a comparative level as when young, allowing the patient to focus at any distance. It is also important to reach a bilateral, symmetrical, and long-lasting presbyopia reversal that is free from ocular pathologies. Whatever approach is used, it must be safe, practical, aesthetical, and economical.

One presbyopia reversal procedure that does not use biomaterials such as an IOL is anterior ciliary sclerectomy, a technique developed by Spencer Thornton, MD. This procedure showed immediate promise, however, regression occurred within 6 months. Many researchers developed implants that preserved the increase of circumferential diameter in the anterior chamber created by anterior ciliary sclerectomy.

Laser presbyopia reversal is an adaptation of anterior ciliary sclerectomy that employs an Erbium laser to excise scleral tissue. The use of delayed healing allows a flexible tissue to fill the incision over 6 to 12 weeks, resulting in an increased circumferential diameter of approximately 10 mm.

SURGICAL PROCEDURE
Laser presbyopia reversal is performed under topical anesthesia. My colleagues and I have performed laser presbyopia reversal on 242 eyes (ie, 121 patients, age range 49 years to 72 years). Follow-up ranged from 1 to 4 years. The following inclusion/exclusion criteria were used: distance UCVA 20/25 or better in each eye; accommodation no greater than 2.50 D, stable presbyopia; manifest refraction spherical equivalent of -0.50 D to +0.75 D; greater than 0.75 D of astigmatism in each eye; IOP range greater than 9 mm Hg; good convergence; normal gonioscopy, topography, axial length, and scleral thickness; no systemic or ophthalmic disease; and prior refractive surgery is allowed.

The steps below outline our surgical procedure:
• A lid speculum is placed;

• Incisions are marked with a Mallo marker;

• A full peritomy is performed;

• After coagulation to create a clear field, four pairs of eight incisions are placed in the sclera at 1:30, 4:30, 7:30, and 10:30 o'clock. The incisions begin 0.5 mm from the limbus and continue for 4.5 mm. The incisions should be at least 80% of the depth of the sclera.

• The OptiVision laser (SurgiLight, Inc., Orlando, Florida) is set at 20 Hz and 20 mJ.

• Following topical anesthesia, the laser fiber ending in a conical contact tip delivers the laser energy—through a fine layer of balanced saline solution to the sclera—after a partial superior and a partial inferior peritomy are performed. The peritomy is closed with a single suture or with tissucol.

Following surgery, the patient is given antibiotic and antiinflammatory drops QED. They also receive wetting drops and complete push-up exercises. Postoperative examination occurs under slit-lamp, and near UCVA is tested. We have noticed near UCVA usually improves to approximately J2.

RESULTS
Patient cooperation is critical to the procedure's outcome. They should practice reading every hour. Preoperatively, the mean correction applied to achieve 20/20 near visual acuity was 2.32 D. Following surgery, this correction immediately dropped to about 0.25 D. By 24 months, the correction applied was about 0.50 D, which matched those reported by Oscar Mallo, MD. He reported a 0.25 D regression over 2 years, and all patients were J1.

In our series, all patients improved accommodation to a normal level, and intermediate distance was excellent. Distance vision also improved slightly. No changes between preoperative and postoperative topography measurements were evident. This is because laser presbyopia reversal is not a refractive procedure, but a procedure that restores accommodation. There were also no changes observed under the slit-lamp. We did notice changes in the length of the three components of the ciliary muscle (Figure 1), and no complications have been reported in this patient population.

Laser presbyopia reversal is a simple and reproducible procedure that provides an improved level of care for the presbyopic patient. It is the only procedure that restores accommodation, completely providing improved near, intermediate, and distance vision. Because the procedure is not performed in the optical path, there are no halos or glare, no aberrations, and no loss of contrast sensitivity. It restores a natural binocular stereoscopic vision at all distances. Worldwide follow-up on this Conformité Européenne-approved procedure is now at 5 years, with excellent results.

Stefano Pintucci, MD, PhD, practices at Oftalmia, in Rome. Dr. Pintucci states that he has no financial interest in the products or companies mentioned. He may be reached at telephone: +39068411884; fax +39068559271; or spintucci@getnet.it.

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