Choice of LASIK, lens implantation hinges on assessment, patient selection

Intraocular contact lenses involve risks such as retinal detachment and pupillary block. LASIK platforms vary in predictability of outcomes.

Karl G. Stonecipher

Meticulous preoperative assessment is critical to properly selecting patients for either LASIK or lens implantation and optimizing visual outcomes, a speaker said.

Karl G. Stonecipher, MD, presented pearls on choosing lens-based surgery or LASIK to treat moderate to high myopia with astigmatism. He spoke during Refractive Subspecialty Day preceding the joint meeting of the American Academy of Ophthalmology and the Middle East Africa Council of Ophthalmology in Chicago.

Refractive lensectomy, or refractive lens exchange, is effective for specific indications, according to Dr. Stonecipher.

“It works in the higher myopes in certain indications as long as you look at the patient preoperatively and have them evaluated appropriately,” he said.

Risks associated with refractive lensectomy include cystoid macular edema, retinal detachment, endophthalmitis, the need for enhancement and unpredictable IOL power, Dr. Stonecipher said.

Intraocular contact lenses

Intraocular contact lenses, or phakic IOLs, yield positive visual and refractive outcomes in younger patients, Dr. Stonecipher said.

“[This technology] is great in younger patients with thin corneas with higher levels of myopia,” he said. “I think that is very appropriate. In fact, we have used it in our clinic quite extensively and gotten great results.”

Dr. Stonecipher cited data showing that intraocular contact lenses yielded better postoperative uncorrected visual acuity than preoperative best corrected visual acuity in approximately one in four patients. Overall, the postoperative UCVA is better than the preoperative BCVA in over 90% of cases prior to any enhancements, which is important, he said.

U.S. military studies have shown little difference between outcomes of intraocular contact lenses and LASIK, except in contrast sensitivity and low-contrast visual performance. However, lens implantation poses the potential for several risks, such as endothelial cell loss, cystoid macular edema, retinal detachment, pupillary block and cataract formation, Dr. Stonecipher said.

“And with our current technology in the United States there is the need for enhancement if there is a significant level of astigmatism,” he said.

LASIK predictability

The surgeon’s choice of excimer laser platform for performing LASIK significantly influences refractive predictability. For example, the Visx platform (Abbott Medical Optics) yielded outcomes that deviated significantly from patient nomograms in the higher refractive errors. Dr. Stonecipher noted that ablation time of the Visx doubled that of the WaveLight platform (Alcon). Ablation speed is inconsequential in the treatment of up to 7 D of myopia with 2 D or 2.5 D of astigmatism but is vital in cases of higher refractive error, he said.

“I don’t think [ablation speed] is a big issue for the lower refractive levels,” he said. “But when you get to these higher levels, the need for speed is important.”

Dr. Stonecipher also referred to data showing slightly higher refractive and visual predictability with the 400-Hz iteration of the WaveLight Allegretto Wave Eye-Q laser than with the 200-Hz version. Data were published in the Journal of Refractive Surgery.

Ablation speed was a major determining factor, Dr. Stonecipher said.

“We are getting differences even between the 200- and 400-Hz [lasers] … primarily because of speed,” he said. – by Matt Hasson

Reference:

• Stonecipher KG, Kezirian GM, Stonecipher M. LASIK for –6.00 to –12.00 D of myopia with up to 3.00 D of cylinder using the ALLEGRETTO WAVE: 3- and 6-month results with the 200- and 400-Hz platforms. J Refract Surg. 2010;26(10):S814-S818.

• Karl G. Stonecipher, MD, can be reached at 3312 Battleground Ave., Greensboro, NC 27410; 336-288-8823; fax: 336-288-8483; e-mail: stonenc@aol.com.
• Disclosure: Dr. Stonecipher is a paid consultant for Alcon and WaveLight.