Expectations and Exit Strategies

No technique for correcting presbyopia is perfect – a compromise always has to be made. But I believe that solutions of the corneal plane are the best for younger patients; there are many benefits and a few approaches you can take. If you have a good laser available, it can be put to good use in the cornea – presbyLASIK is well-established, and studies with long-term follow-up are available (1)(2). Newer techniques have also emerged; for example, laser blended vision, which has seen good success rates (3). PresbyLASIK can simultaneously correct sphere and astigmatism, is mostly reversible, and gives the option of extraocular correction – if the patient is not happy, you can always try a contact lens to avoid further laser treatment. Other approaches do exist (thermal keratoplasty and conductive keratoplasty, for example), but, because they are not widespread and have to some extent disappeared from the market because of large amounts of regression, I will not cover them here.

Similarly, decentered ablations in presbyLASIK are no longer used. Central and peripheral presbyLASIK has been published on extensively; if you want to get into the details, Ioannis Pallikaris has done an excellent survey of these techniques (4). Central presbyLASIK is good for near vision, but doesn’t perform well with distance vision and is a little difficult to correct. Peripheral presbyLASIK is good for distance vision and has good safety, but provides limited near vision. Patient satisfaction is generally high, but some patients can lose up to two lines of near visual acuity. Spectacle independence is better in hyperopes than in myopes, and patient selection and management are crucial. However, it’s important to remember that laser correction is a static modification of a dynamic process – so as I said before, it’s always a compromise. Moreover, there are few long-term studies on the effect of epithelium remodeling over time and the progression of presbyopia.

Another option that I believe holds great promise are corneal inlays; indeed, the cornea is the best place to put a piece of plastic in the eye to treat presbyopia. Inlays have two primary advantages: they are tissue sparing and removable. But there are also the challenges of ensuring that the optics are effective and that the results are stable and predictable. A few options are now available, including intracorneal microlens systems, such as the Raindrop, Icolens and Flexivue – and the small aperture depth of focus Kamra inlay, which has been approved in the US and implanted in over 3,000 cases in the last year (and more than 22,000 cases since studies of it began) (5). All of these implants are highly biocompatible, and are almost fully reversible; if the patient is not happy, take them out early, and the cornea essentially reverts back to normal. My advice in these cases? Manage patient expectations, always have an exit strategy and remove corneal implants early if the patient isn’t happy. For younger patients without cataract who don’t want to risk intraocular problems, corneal techniques can offer better safety and are reversible – if you take out the inlay, it’s gone. There’s no risk of endophthalmitis, capsular rupture, refractive surprises as with IOLs, vitreous loss, retinal detachment or secondary cataract, which means you lessen your chances of an unhappy patient with side effects that are difficult to treat. This is why, in my view, the cornea is the way to go! The author reports no conflicts of interest relevant to the content of this article.