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Consider refractive lens exchange in patients with presbyopia
Offer your patients options beyond glasses and contact lenses.
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We know that the crystalline lens is not an ideal piece of equipment, or at least not a durable one. It thickens and changes color, imbibes UV radiation and essentially stops functioning properly by the fourth or fifth decade of life, well before most of us are ready to give up on good vision.
The good news is that we have the technology available to safely replace the crystalline lens with one that will provide good distance vision or, in some cases, a range of vision from near to far. So why do many of us want to wait as long as possible to refer a patient for lens surgery? If the car is not running properly, do we wait for a complete breakdown? Of course not.
In the era of femtosecond laser surgery, refractive surgical guidance tools and advanced IOLs, a diagnosis of cataract is not a bad thing. In fact, I would argue that patients should be referred for cataract surgery as soon as they meet the minimum necessary requirements. This can include not only decreased Snellen acuity, but also problems with glare, color vision and, more importantly, a reduction in the quality of life.
Taking that argument a step further, even before visually significant cataract exists, some are terming this inherent change in the lens structure as dysfunctional lens syndrome. Refractive lens exchange (RLE) may be the best option for some patients.
RLE candidates
Great candidates for RLE include presbyopes who want to be free of glasses or contact lenses, patients who want a full range of vision but are dissatisfied with the quality of their vision with progressive spectacles or monovision, moderate to high myopes (at least 3 D) as well as all hyperopes. Astigmats can also often achieve better quality of vision with toric IOLs that correct astigmatism closer to the nodal point instead of on the spectacle or corneal plane, or the laser can be used in combination with RLE to obtain emmetropia.
Patient age plays a large role in the recommendation. It is unlikely to have a discussion for a RLE with a 25-year-old. That patient still has many years of accommodation and would be better served by a corneal refractive procedure if he or she wants to get out of glasses or contact lenses. Yet from the onset of presbyopia, RLE should at least be part of the conversation. After age 50 or 55, it is incumbent upon the optometrist to discuss RLE as an option that will correct patients’ refractive error and eliminate the need for future cataract surgery. In theory, they will have great vision for the rest of their lives, barring any disease state.
This is an easy conversation to have with a presbyopic patient who asks about LASIK, although if you see early signs of lens changes, a corneal procedure is not in their best interest. Talk about the pros and cons or suitability of LASIK and ask patients if they are familiar with cataract surgery. Advise the patient that they can have essentially the same procedure to replace their aging lens in a matter of minutes, with the potential to see without glasses after surgery.
Patients who have unrealistic expectations of perfect vision in all situations, those with active macular or corneal disease and those with significant ocular surface problems that cannot be resolved are not great candidates for RLE. In my experience, low myopes are also difficult to satisfy. They are accustomed to seeing up close naturally and tend to have trouble comprehending what it will be like to lose that ability.
Weighing risks, benefits
Risks to intraocular surgery exist, of course. But the data suggest that the risks of lens surgery in the U.S. are small. An analysis of more than 200,000 Medicare patients undergoing cataract surgery over a 12-year period found that the rate of serious, sight-threatening adverse events such as retinal detachment (RD) or endophthalmitis was 0.5% and declining (Stein, et al.).
While some have reported that lens surgery significantly increases the risk of RD in high myopes, particularly those younger than 50 years (Colin, et al., and Russell, et al.), others have concluded that the risk of RD in pseudophakic high myopes is similar to that of phakic high myopes (Neuhann, et al.). There has been no reported increase in RD in hyperopes or lower myopes.
Less sight-threatening risks, including corneal or macular inflammation and edema, posterior capsular opacification, ptosis or IOP rise, can largely be treated and resolved. There are technology-specific risks that warrant discussion in the context of specific procedures or IOLs that are better left to the informed consent process after a patient has decided to pursue RLE.
Helping patients weigh these limited risks against the real benefits of high quality, long-term vision and potential spectacle independence is part of the optometric acumen.
Newer premium IOL options, in particular, have been exciting. Many of my patients are now being implanted with the low-add (+2.75 D or +3.25 D) Tecnis multifocal lenses (Abbott Medical Optics), which offer better intermediate vision for computer use and other activities that are important to RLE patients. In the clinical trials for these lenses, not only were the rates of spectacle independence and satisfaction high, but the rate of night vision symptoms was comparable to or lower than that of the monofocal control group. This implies that patients are not making much of a trade-off to get the near vision they want, which alleviates a huge concern for many optometrists.
I would recommend low-add lenses for the majority of patients who want spectacle independence, although a traditional multifocal might still be the best option if close work is the highest priority. For astigmats, we now have more toric options for a wider range of astigmatism, as well as a toric lens on the Crystalens platform (Bausch + Lomb).
Integrated care
Optometrists should play a central role in the continuum of care for refractive surgery (corneal or lenticular) patients. First, of course, is educating and guiding patients through the RLE decision-making process. Choosing an out-of-pocket procedure such as RLE is a big decision, one that goes much better if patients have to think it through before going to the surgery center.
Preoperatively, we need to ensure that the ocular surface, especially the tear lens, is in good shape. Otherwise, patients will almost certainly experience symptoms or fluctuations in vision after surgery and blame the procedure, their surgeon and us for the problem.
After surgery, I continue to treat the ocular surface and also watch carefully for any posterior capsular opacification that could decrease quality of vision. Long after the postop period, we can continue to provide these patients with sunglasses or reading glasses if needed and see them for annual ocular health exams. Most importantly, we can continue to have a relationship of trust. You never want patients to say, “Well, my doctor never told me about that ...”
As optometrists, we are our patients’ advocates. If we are in the business of helping patients see better — as I believe we are — then we should take seriously all the options for achieving that goal, from glasses to contact lenses to corneal and lenticular refractive surgery, and take an active role in guiding patients to make the best choices.
- References:
- Stein JD, et al. Ophthalmology. 2011;118(9):1716-1723; doi: 10.1097/ICU.0b013e3283524068.
- Colin J, et al. Ophthalmology. 1999;106(12):2281-2285; doi: http://dx.doi.org/10.1016/S0161-6420(99)90526-2.
- Russell M, et al. J Cataract Refract Surg. 2006;32(3):442-445; doi: 10.1016/j.jcrs.2005.12.095.
- Neuhann IM, et al. J Cataract Refract Surg. 2008;34(10):1644-57; doi: 10.1016/j.jcrs.2008.06.022.
- For more information:
- Marc R. Bloomenstein, OD, FAAO, is the director of optometric services at Schwartz Laser Eye Center in Scottsdale, Ariz., and a member of the Primary Care Optometry News Editorial Board. He is an adjunct assistant professor at New England College of Optometry and Southern California College of Optometry and co-founder of the Optometric Council on Refractive Technology. He can be reached at mbloomenstein@gmail.com.
Disclosure: Bloomenstein is a consultant for Abbott Medical Optics and Bausch + Lomb.