Which small-aperture therapy would be your approach?
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It depends on the patient
For patients with presbyopia, it depends on factors such as age of the patient or if there is any other pathology.
Early on in presbyopia, I would vote for pharmacologic therapy. Pharmacologic therapies are simple, easy to use and reversible. If you do not like its effect, you can just stop the drops. If someone can use an eye drop and improve their presbyopia, I cannot think of any downside.
Drops are simple and not something a patient would have to use all the time. If a patient were going out cycling or doing some sort of athletic endeavor in which they would not need to see up close but want to focus on distance vision, the drops could be discontinued. This is a great option for the younger presbyope, someone who is 45 to 60 years old. That is the sweet spot.
Patients who are hyperopic presbyopes are more suitable for a clear lens exchange with a presbyopia-correcting IOL. If they are appreciating both their hyperopia and presbyopia, then they are miserable about all of it. The tricky thing with hyperopes is if they have a large angle kappa or a large cord length mu, which you can measure preoperatively, some of those patients are not well suited to a multifocal IOL and may have higher-order aberrations. If there were a pharmacologic drop these patients could use with their current contact lens prescription, if they were fine with wearing contact lenses but they did not enjoy reading glasses, I think a pharmacologic therapy would be an excellent option.
When someone is slightly older, in their 60s or above, and they are starting to experience lenticular changes and fully appreciating their presbyopia, then doing either early cataract surgery or a lens exchange and correcting it with a presbyopia-correcting IOL would be appropriate. This, of course, is assuming all other things are equal in terms of a normal cornea. If so, lens implant technology would be a great option.
In terms of a small-aperture IOL, the sweet spot for these is with irregular corneas. I am excited for the technology but for the more abnormal corneas. If a patient has a history of RK, corneal scar or keratoconus, that is the sweet spot for a small-aperture IOL.
I am not excited about corneal inlays. There was the disaster of the Raindrop inlay (Optics Medical), which was called off the market. If you looked at the FDA results for the Kamra inlay (CorneaGen), a large percentage of patients experienced decreased vision, halos and other aberrations. Some patients and some doctors have had success with an inlay, but I never embraced the technology.
In terms of other devices, such as presbyopic scleral rings or implants, they resulted in problems with anterior segment ischemia. I am not a fan of the implant technology. The risk benefit is not in a patient’s favor.
Early on in presbyopia, I would use pharmacologic therapy. Even with a patient with an IOL, you can potentially use pharmacologic therapy as well. If that works, it would be excellent.
We do not have a perfect IOL, but extended depth of focus, multifocal and trifocal IOLs all have plusses and minuses. We could use a great accommodating IOL that works well for a full range of vision, but right now, there is nothing like that available in the U.S.
Audrey Talley Rostov, MD, is an OSN Cataract Surgery Board Member.
IC-8 IOL is the choice
My 6-year experience with the IC-8 (AcuFocus) makes me biased to select the IOL as my small-aperture therapy of choice. I have had experience using the IC-8 monolaterally, bilaterally, on eyes with virgin corneas and on post-refractive surgery eyes. The surgical technique, injector and IOL calculation have been developed and refined to give us consistent outcomes. With a – 0.75 D target refraction, the uncorrected distance and near vision are usually 20/25, with defocus curves consistent with extended depth of focus. Small-aperture optics corrects the – 0.75 D intended myopia to still give good distance vision and provides a wide enough range of defocus for presbyopia correction as well as making the lens forgiving for refractive misses.
Additionally, the small aperture screens out the deleterious effects of residual postoperative astigmatism up to 1.5 D and the unwanted distortions from aberrated corneas. For me, the IC-8 functions as an extended depth of focus presbyopia solution with low toric correction capabilities. The typical recommendation is to use the IC-8 in the nondominant eye. In my patients, if they are satisfied with the outcome of the first eye and request the same lens for the fellow eye, I do not hesitate to implant the IC-8 in the second eye. This positive patient feedback and request for the lens is my criteria for doing bilateral implantation. Aside from being an ideal lens for patients who have had previous refractive surgery, I believe regular patients with cataracts will also greatly benefit from the IC-8 small-aperture IOL.
Robert E. Ang, MD, is a senior consultant and head of cornea and refractive surgery services at the Asian Eye Institute in Makati City, Philippines.
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