lasik new york

LASIK VERSUS Refractive Lens Implants

How to incorporate new refractive lens technology in a co-management relationship.

Co-managetnent of vision corHitection procedures has fostered mutually beneficial relationships between optometrists and ophthalmologists. The advent of phakic, multifocal and accommodating intraocular lens implants broadens co-management opportunities. We can now work together to provide patients, impaired by the highest levels of refractive error, sight restorative surgery.

There are several critical stages in the co-management relationship. First, determine which procedure is optimal for each patient. After counseling the patient extensively, you and the surgeon must decide which procedure is optimal. second, compiete a thorough preoperative work-up. The operative procedure is then performed, and lastly, you must provide postoperative care. Being knowledgeable about new lens technologies and understanding the respective roles of the optometrist and ophthalmologist throughout this process can help patients achieve the best possible outcome.

Lens implants vs. LASIK

Not all patients are candidates for lens implantation, just as not all patients are candidates for LASIK. Parameters like refractive error, age, presence of cataract, corneal thickness and shape all impact whether one procedure or the other is appropriate for a particular patient. There are also patients who may be candidates for either LASIK or IOL implantation. Patients fall into four categories when making the determination about which refractive procedure is optimal for each patient.

* LASIK candidates. Pre-presbyopic patients with refractive errors of less than -8.0OD of myopin or less than +4.0OD of hyperopia, are generally good candidates for LASIK surgery. These patients must have healthy corneas with appropriate thickness in relation to the refractive error, normal corneal topography, normal tear film and the absence of significant medical conditions like diabetes, collagen vascular diseases and pregnancy. Wavefront-optimized and wavefront-guided treatments provide excellent visual results in this group of patients.

* Phakic lens candidates. We prefer phakic lens implants in myopic patients with errors of -10.0OD or more. The ablation profile in LASIK can lead to an increase in higher-order aberrations with subsequent glare and night vision problems for this group.

These lenses are also a good option for patients with refractive errors as low as -5.0OD in whom LASIK is contraindicated due to insufficient corneal thickness, irregular astigmatism or profound dry eyes.

* Multifocal/accommodating lens candidates. Presbyopic patients, including patients with early cataracts, may prefer the multifocal or accommodating lens implants because they can achieve good distance and near vision. Although monovision LASIK is an option, it is often unacceptable because depth perception is compromised.

These implants are ideal for high hyperopes (+4D or greater) who are most interested in eliminating their dependency on distance and reading glasses. However, patients with myopia above -6.0OD are at a higher risk for retinal detachment after cataract or refractive lens exchange. Counsel patients about the additional risk appropriately.

* Candidates for both procedures. Myopic patients who fall between -5.00D and -10.00D with sufficient corneal thickness and normal topography may be candidates for either procedure.

For this group, it is imperative to discuss options with the patient to determine which is the best procedure. Considerations include age, range of myopia, amount of astigmatism, endotheHaI cell count and anterior chamber depth.

Pre-op work-up

Co-managing doctors must agree on the division of labor when performing the pre-operative tests. Unlike LASIK, which is typically performed bilaterally, IOLs are implanted one eye at a time. Depending on surgeon and patient preference, there may be a one to four week interval between procedures for the first and second eyes. During this interval, patients may need to wear a contact lens in the untreated eye to minimize anisometropia or aniseikonia. In our case, Dr. Kasslaow performs all pre-operative tests with the exception of the anterior chamber depth, endothelial cell count, ?-scan and IOL calculation.

No matter what the choice for correction, a thorough and precise preoperative work-up must be performed. Critical tests include: a careful dry and wet refraction; pupil size measurement; keratometry; IOP measurement and dilated fundus exam. The refraction is the most important part of the preoperative work in these patients. Young, highly myopic patients can easily accommodate more minus in their prescription. Take care to measure the refraction both with contact lenses in (over-refraction) and after lenses have been kept out for the appropriate time (one week for soft lenses, two weeks for gas permeable). In addition, for highly myopic refractions, keep the vertex distance constant to ensure accuracy. A full cycloplegic refraction should be performed as well.

posted by wording @ 9:39 PM