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LASIK a reliable method for low hyperopia
Clear lens exchange is preferred for higher refractive errors and older patients.
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Hyperopic refractive surgery has always been more of a challenge than myopic refractive surgery. Lately several options for surgical correction of hyperopia have begun to show successful, stable results.
Ocular Surgery News spoke to four well-known refractive surgeons about their preferred techniques for hyperopia correction. Their consensus was that hyperopic LASIK is a good option for low levels of error, and lens implantation or exchange is effective for higher degrees of correction.
For low to moderate hyperopia, the surgeons we interviewed were satisfied with the results of hyperopic LASIK. Above that level, clear lens exchange (CLE) or phakic IOL implantation was preferred. Some said they preferred lens exchange in older patients in whom there might be an incipient cataract.
Preferences
The surgeons we interviewed had varying preferences for refractive surgery techniques for hyperopia. LASIK was the preferred choice overall. Use of alternative procedures such as phakic IOLs, CLE, LASEK and intracorneal implants varied from surgeon to surgeon.
Hideharu Fukasaku, MD, of Yokohama, Japan, said he has operated on refractive errors between +3 D and +6 D with good results. He prefers to use LASIK in younger patients. He uses CLE on patients older than 40 years of age, because “there is often lens opacity, and cataract extraction will eventually follow,” he said.
If possible, he prefers to avoid surgery on patients with tight lids, small palpebral openings or small corneas.
Michael Knorz, MD of Mannheim, Germany, said his upper limit for hyperopic LASIK is +3 D.
“LASIK is easy to use and has excellent results in low hyperopia, up to +3 D,” Dr. Knorz said. “In higher hyperopes, however, results are not as good, and patients complain about poor night vision. I therefore prefer CLE in hyperopia of more than +3 D. If the patient is presbyopic or close to presbyopia, I combine the CLE with the Allergan Array multifocal IOL, which provides excellent distance and near vision.”
Dr. Knorz said he will perform CLE in older patients with errors higher than +6 D, but he is reluctant to do so in patients younger than 40 years. For younger patients with more than 6 D of hyperopia he said he recommends wearing contacts and waiting for better technologies.
CLE can be adjusted postoperatively, Dr. Knorz noted. “As lens power calculation is not 100% accurate, some patients will retain some residual ametropia after CLE. In these cases, an additional LASIK will be performed about 3 months later,” Dr. Knorz said.
Dr. Knorz has been involved in investigations of the Permavision intracorneal lens implant, and he uses this option in patients with hyperopia of +3 D to +6 D. The Permavision implant has received the CE Mark, he said.
António Marinho, MD, of Porto, Portugal, said he uses LASIK in patients up to +3.5 D and to correct any degree of astigmatism. With errors above +3.5 D, he prefers to use a phakic IOL, the Ophtec Artisan.
He said for implantation of the Artisan, the anterior chamber depth must be greater than 2.8 mm. If phakic implantation is not possible he employs CLE.
“The results with the Artisan IOL and with CLE are very accurate,” Dr. Marinho said.
Juan Murube, MD of Madrid, does not operate on patients with errors greater than +4 D sphere. He primarily uses LASIK for hyperopia. He said he has used laser epithelial keratomileusis (LASEK), but it is subject to regression of effect. He has also used contact thermokeratoplasty with poor results because of inaccuracy of correction, regression and glare.
“Most surgeons think that LASIK is more predictable and has more refractive stability than other techniques. In Spain other techniques are used, but they are more [infrequent],” Dr. Murube said.
Preferred instruments and medications
Lasers used by these surgeons include the Bausch & Lomb Technolas 217 and the Iso-Beam 200 from Kera Technology.
Dr. Fukasaku said uses the Bausch & Lomb laser for wavefront-guided ablation.
“This is an excellent laser, and wavefront guidance yields excellent results even in patients with higher-order aberrations that yield poor clinical refractions results under normal conditions,” Dr. Fukasaku said.
He uses the Bausch & Lomb Hansatome microkeratome with a new, smaller suction ring in patients with small eyes.
“This instrument is 1.3 mm smaller than its standard counterpart and better suited for the small palpebral aperture and small eye,” Dr. Fukasaku said.
He recently started using the 180-µm microkeratome head. He said less suction is needed, with the vacuum power closer to 80 mm Hg than to 100 mm Hg. He said he has had several near-buttonhole experiences with thinned flaps using the 160-µm head.
“This is especially true with corneas of less than 44.00 D keratometry,” Dr. Fukasaku said.
Dr. Knorz said he uses a 7-mm fully corrected central optical zone and a transition zone of up to 9.5 mm on his Technolas 217 laser.
“As a rule, the central zone should be as large as possible, while the ablation should still fit under the flap as much as possible. I believe that 7 mm is the minimum, 8 mm is even better.” Dr. Knorz said. “One must cover the back of the flap during the ablation as a large number of shots can hit the flap in hyperopic ablations with large zones.”
Dr. Marinho said he uses the Hansatome to create a 9.5 mm flap.
Dr. Murube uses the Kera Technologies Iso-Beam 200. He said it has dual synchronic flying spot with a profile of gaussian and fractal ablation. The spot diameter is 0.9 mm and the frequency is 400 Hz, he said.
“For hyperopic corrections I use the Carriazo-Barraquer microkeratome with a superior hinge. Using its interchangeable suction rings provides a flap with central depth of 160 µm,” Dr. Murube said. “In special cases in which I want a larger or smaller central flap depth, I use the Automated Corneal Shaper (Bausch & Lomb).”
Drug regimens
Dr. Fukasaku administers a fluoroquinolone antibiotic for 6 days before LASIK surgery. For postoperative therapy, he administers a standard antibiotic-steroid combination plus a nonsteroidal anti-inflammatory drug.
Dr. Marinho said he administers antibiotic and steroid medications postoperatively for 1 week after LASIK.
Dr. Murube administers TobraDex (tobramycin dexamethasone, Alcon) eye drops 4 times daily the first postop week, decreasing the dosage to one drop daily after 4 weeks.
Dr. Knorz also administers TobraDex but recommends using it 3 times daily for 5 days after the procedure. With CLE, he administers it for 2 to 3 weeks.
For Your Information:
- Hideharu Fukasaku, MD, can be reached at Yokohama S.T. Building, 1-11-15 Kitasaiwai, Nishi-ku, Yokohama 220-0004, Japan; +(81) 45-3250055; fax: +(81) 45-3250054; e-mail: h-f-eye@po.iijnet.or.jp.
- António Marinho, MD, can be reached at R. Eugenio de Castro 170-41, Porto 4100 Portugal; +(35) 22-2007538; fax: +(35) 22-2031079; e-mail: marin@mail.telepac.pt.
- Juan Murube, MD, can be reached at Clinica Murube, Oftalmologia, San Modesto, 44, 28034 Madrid, Spain; +(34) 91-7290055; fax: +(34) 91-7340956.
- Michael Knorz, MD, can be reached at 14 Leibniz St., Mannheim 68165, Germany; +(49) 62-13833410; fax: +(49) 17-26298010; e-mail: knorz@eyes.de.
- Bausch & Lomb Surgical, manufacturer of the 217Z Laser, can be reached at 180 Via Verde Drive, San Dimas, CA 91773 U.S.A.; +(1) 909-971-5100; fax: +(1) 909-971-5124; Web site: www.bausch.com.
- Kera Technology, manufacturer of the Iso-Beam 200, can be reached at 5800 S. Semoran Boulevard, Suite A, Orlando, FL 32822 U.S.A.; +(1) 407-381-4102; fax: +(1) 407-282-3643.