Managing Refractive IOL Expectations

Our three-step approach delivers successful outcomes for presbyopic IOL patients.

BY WILLIAM B. TRATTLER, M.D. AND CARLOS BUZNEGO, M.D.

The out-of-pocket investment that accompanies new technology IOLs, whether for cataract or refractive surgery, often emboldens patient expectations and demands. Yet, even under the best circumstances in seemingly "perfect" candidates, there are challenges to routinely achieving success with presbyopic IOLs. For example, postoperative surprises such as loss of best-corrected vision due to subtle corneal changes or less-than-perfect macular function can lead to significant patient dissatisfaction. Early posterior capsular opacities that affect vision can result in an unhappy patient as well, if the patient was not educated about this common situation prior to surgery.

With these challenges in mind, we have incorporated a three-step approach in our cataract and refractive surgery practice that can bring both patient and surgeon to a satisfactory conclusion.

In a nutshell, the three-step plan requires the patients and surgeon to work together to obtain the optimal visual result. First, it is crucial for the surgeon and staff to clearly delineate what the patient can expect in terms of risks and outcomes; second, the surgeon should work with the patient to select the appropriate IOL that will meet his expectations and also work synergistically with any pre-existing pathology; and finally, the surgeon should employ perioperative therapeutics to reduce the risk of cystoid macular edema (CME), infection and dry eye to achieve the best possible postoperative visual acuity.

Patient management plan

Preoperative screening is a prerequisite to this step-wise approach to achieving success with refractive IOL patients. Patients will often present with demands for multifocal IOLs because they have friends or family members who have been able to reduce or eliminate their dependence on spectacles after such surgery. It is critical to communicate that these IOLs will not be an option if presurgical topography identifies irregularities such as irregular astigmatism, signs of early keratoconus or keratoconus itself. In some patients with significant astigmatism, a toric IOL may be a better option, especially when patients have corneal irregularities that do not lend themselves well to other procedures that reduce astigmatism, such as arcuate keratotomies or even laser vision correction.

Presbyopic IOLs may be contraindicated in patients who have pre-existing macular issues, as well. Epiretinal membranes, macular degeneration, vitreomacular traction syndrome or a previous history of macular edema can significantly affect a patient's contrast sensitivity. Because multifocal IOLs also reduce contrast sensitivity, these IOLs would be less desirable in patients with macular conditions. In the right patients with mild macular issues, accommodating intraocular lenses can potentially be offered, but the patient needs to be aware of the potential for reduced quality of vision postoperatively due to their pre-existing condition. For some patients with more advanced macular issues, the added expense of an accommodating IOL — without advance knowledge of the full extent of the reduced quality of vision — is reason enough to recommend a monofocal IOL.

As with laser refractive surgery, it is in the surgeon's and patient's best interest to identify potential problems as early in the process as possible. By the time the patient is presented with the informed consent, the patient should have a clear understanding of his expected outcome as well as the conditions that can potentially affect that outcome postoperatively.

Choosing the Right IOL

Choosing the best IOL option and prescreening for irregularities sets the stage for the surgical plan. There are three FDA-approved latest generation presbyopic IOLs: The ReSTOR (Alcon, Fort Worth, Texas), the ReZOOM (Advanced Medical Optics [AMO], Santa Ana, Calif.) and the crystalens (eyeonics, Aliso Viejo, Calif.). Each of these lenses has its strengths and weaknesses. When helping patients choose the best option, we point out that the strength of the ReSTOR IOL lies in its ability to provide excellent near vision and solid distance vision, but that in doing so some tradeoffs are made for the intermediate vision. Conversely, we explain that the ReZOOM IOL's strength lies in providing excellent intermediate and solid distance vision, while near vision can be challenging.

Finally, we point out that in our experience the crystalens provides excellent overall quality of vision. However, it requires a strategy of mini-monovision (or blended vision), where the dominant eye is set for distance and the non-dominant eye is set for -0.75.

Head Off Postop Problems

After determining the appropriate presbyopic IOL and performing complication-free surgery, no surgeon wants to have to explain why the patient is not seeing well. Eliminating or greatly reducing potentially vision threatening postoperative CME helps prevent that scenario from taking place. Pretreating with a combination of NSAIDs and steroids improves the odds of a successful outcome by reducing the risk of CME. NSAIDs work by blocking the production of prostaglandins. Pretreatment with NSAIDs reduces the quantity of preformed prostaglandins present in the anterior chamber of the eye prior to cataract surgery.

To examine the effectiveness of this strategy, we participated as investigators in a large, multicenter study comparing prednisolone acetate 1% alone to a combination of ketorolac 0.4% (Acular LS, Allergan) and prednisolone acetate 1%.^1,2 By pretreating with ketorolac and continuing with it for 4 weeks postoperatively, patients had a dramatic reduction in the risk of macular swelling as compared to patients without ketorolac.

This study also revealed that pretreatment with ketorolac resulted in improved quality of vision, as measured by contrast sensitivity. This is especially important for patients who receive a multifocal IOL, because these lenses can reduce contrast sensitivity.

Although macular thickening is a common reason for slow visual recovery following cataract surgery, dry eye signs and symptoms can also be problematic during the early postoperative period. However, a recent study verified the positive benefits of the use of topical cyclosporine in presbyopic IOL patients.³ We also find that the addition of twice-daily topical cyclosporine-A (0.05%) (Restasis, Allergan) can be beneficial to our presbyopic IOL patients. If patients have obvious signs of dry eye on clinical exam prior to surgery, or their topography is irregular due to dry eye, we typically start cyclosporine in the preoperative period and continue it postoperatively. Some patients will also benefit from punctual plugs.

The Three-Pronged Approach is Crucial

In summary, presbyopic IOLs have enabled surgeons to provide patients with excellent visual results. However, consistently achieving a high degree of patient satisfaction requires that the surgeon spend time managing patient expectations and communicating realistic risks and likely outcomes. Furthermore, surgeons need to evaluate patients preoperatively to identify pre-existing corneal and macular conditions that may reduce the chances for success.

Lastly, our participation as sub-investigators in the Wittpenn study, along with our own anecdotal experience, supports our strongly held belief that the combination of pre- and postoperative topical NSAIDs and topical steroids work synergistically to help provide optimal outcomes in IOL surgery. OM

References

1. Wittpenn J, Silverstein SM, Hunkeler JD, et al. Masked comparison of Acular LS Plus steroid vs. steroid alone for the prevention of macular leakage in cataract patients. Presented at: Joint Meeting of the American Academy of Ophthalmology and Asia Pacific Academy of Ophthalmology; Nov. 10, 2006; Las Vegas.
2. Wittpenn J, Silverstein SM, Hunkeler JD, Kenyon K; ACME Study Group. Subclinical cystoid macular edema reduces contrast sensitivity and final visual acuity in low-risk cataract patients. Presented at: the Association for Research in Vision and Ophthalmology Meeting; May 10, 2007; Fort Lauderdale, Fla.
3. Donnenfeld E, Roberts C, Perry H, Solomon R, Wittpenn J, McDonald M. Efficacy of topical cyclosporine vs. tears for improving visual outcomes following multifocal IOL implantation. Invest Ophthalmol Vis Sci. 2007;48: E-Abstract 1066.

William B. Trattler, M.D., is a corneal specialist at the Center for Excellence in Eye Care in Miami and a volunteer assistant professor of ophthalmology at the Bascom Palmer Eye Institute in Miami. Dr. Trattler has received funding for research, consulting and/or speaking from Allergan, Glaukos, Advanced Medical Optics, Inspire Pharmaceuticals, ISTA Pharmaceuticals, Lenstec, Sirion Therapeutics and Vistakon.

Carlos Buznego, M.D., is an anterior segment surgeon at the Center for Excellence in Eye Care in Miami and a volunteer assistant professor of ophthalmology at the Bascom Palmer Eye Institute in Miami. Dr. Buznego is a speaker, consultant and/or researcher for Alcon, Allergan, Glaukos, Inspire Pharmaceuticals, ISTA Pharmaceuticals, Lenstec and Sirion Therapeutics.