In a recent conversation, Dr Ravi Patel discussed his experience with the IC-8™ Apthera™ lens and how it has revolutionized monovision technology.

How Apthera Has Revolutionized Monovision 

“Monovision has been around for several decades. It was one of the first modalities of correction for presbyopia that was employed with contact lenses, then LASIK surgery, and now cataract surgery.”

“As we all know, monovision has some pitfalls. Patients may compromise their depth perception, have some difficulty in low light illumination, and experience glare. In the cataract surgery arena, Apthera has revolutionized monovision, providing its well-known benefits, including improved functional near vision, without the negative side effects of traditional monovision with monofocal IOLs.” 

“In the cataract surgery arena, Apthera has revolutionized monovision, providing its well-known benefits, including improved functional near vision, without the negative side effects of traditional monovision with monofocal IOLs.”

- Dr Ravi Patel

Patient Selection

“Apthera uses a pinhole aperture to enhance and extend depth of focus, resulting in clarification of vision.1 What’s noteworthy is that all lens technologies that enhance depth of focus provide better range of vision, but you don't really get magnification; this is no different, which is important for surgeons and patients to understand. We're talking about actually improving image quality, which can benefit a large majority of patients.”

“The conversation with the patient starts with preoperative evaluation. You do a comprehensive examination and evaluate the patient carefully to make sure that you choose suitable candidates.”

“If I find out that what's important to them is getting a good functional range of vision and night vision while minimizing disturbances, then Apthera is a great technology for them. If it's somebody who is really interested in multifocal optics and really wants to see J1 plus (what I call micro-print) and have symmetrical vision in both eyes, and they don't mind having halos, a diffractive multifocal lens is still a viable technology.” 

“Once I have formulated a strategy, I hear them out, and then present two or three adapted options that I think can work for them. Then I leave it to the patient to make the choice, and that's been successful for us.”

“We consider Apthera for patients who are interested in having a reduction in their need for eyeglasses. If they have some functional needs that they really don't want to wear glasses for, but are concerned about the dysphotopsia profile, including glare, halos, and starbursts that are characteristic of the multifocal lenses available or the other available EDOF lenses, Apthera is ‘the’ great option.”

“Patients who already have experience with monovision also benefit from Apthera. People who already wore monofocal contact lenses are already primed to use technology like Apthera.”

“We utilize the iTrace to show us the higher order aberrations present in a way that both the provider and patient can easily understand. There is a feature in iTrace to reduce the pupil size down and report the aberrations present. As we all know, aberrations are highly dependent on pupil size. A pinhole can reduce not only lower order aberrations, such as sphere and cylinder, but higher order aberrations as well. This helps to identify good candidates for the Apthera lens.”

“We screen out patients who don't dilate well, as we know they need 7.0 mm of dilation, and we screen out patients with a history of retinal pathology.”1

Refractive Salute - Man covering one eye“The only thing we have to counsel patients on is to make sure they don't do the ‘refractive salute,’ where they cover one eye and then the other. I tell them we're designed to live life with two eyes open, and as long as they don't walk around doing the salute, they're going to be really happy. The rest is up to the surgeon to do a technically perfect case. Regardless of your preferred technique, meticulous wound construction, maintaining zonular integrity, polishing of the anterior and posterior capsule, and IOL centration are critical steps for this type of technology.”

“When you walk into the examination room for the first postop visit after IOL implantation and patients have a lot of questions or concerns, that's when you fear that you might have missed the mark. When you walk in after Apthera implantation and you see a big smile on the patient’s face, that pretty much says it all. You immediately know that you've not only met their expectations, but you’ve exceeded them because the patient is speechless.” 

Outcomes Relative to Those Reported in US Investigational Device Exemption Study 

“In the pivotal IDE study supporting US approval of the Apthera lens, binocular uncorrected visual acuity in patients who received Apthera was UCDVA 20/20 or better, UCIVA 20/25 or better, and UCNVA 20/30 or better.”1

Comparison Of Binocular Uncorrected Visual Acuities at 6 Months

“We're working within the same parameters used in the IDE study, and we're matching, if not exceeding, those expectations. For some patients, we do a bit of tailoring in the second eye in terms of exactly where that refractive target is. For some patients who want an emphasis on near vision, we target closer to the -1 diopter (D) side of the guidelines. In a more distance- and intermediate-dominant patient, we’ll target closer to the -0.75 D side.” 

“Within that range, I'm finding that the results are exactly as expected, which truthfully tells us that the product is working. In the ‘real’ world, when patients are getting the same outcomes and a similar dysphotopsia profile, it’s quite reassuring the lens works as reported.”

Results With Apthera in Bright and Low Light Conditions

“During daytime situations, my patients are doing really well. They find that with both eyes open, they have the full complement of vision from distance all the way up to near vision. In most cases, their functional near vision is great; they're able to see their phones and read a menu. In bright light situations, they may be able to read a book.”

“We counsel patients who, when reading print, a low contrast medium, will likely need some readers. I haven’t heard about problems with distance vision or depth perception, except for night driving. Near vision is not as good in dim illumination as it is in bright illumination, but I think that’s true for all lens technologies.” 

Advantages With Apthera 

“We're realizing that using the pupil is going to be one of the mainstay methodologies of presbyopia correction. There are topical pharmaceutical products on the market already to reduce pupil size to less than 2 mm.”3

“The central optic zone of the Apthera is 1.36 mm, so we're within that zone. And it's not dynamic. We're always at 1.36 mm, which gives patients more predictable vision. It doesn't matter what time of day it is or what type of lighting situation they’re in. That predictability adds to patient satisfaction and success. With Apthera, you are able to not only give patients a -0.75 D target, so there's still some binocular balance between the two lenses,1 but you're also able to extend that depth of focus an additional 2 to 2.25 diopters to give them true intermediate vision, and true near vision in that one eye.”

“When you implant a traditional monofocal lens, or even a monofocal plus lens, you can set that patient’s power at negative 2. You might get half a diopter more of range. You're most certainly not getting more than 2 diopters of range. Since the defocus curve for Apthera is relatively flat from Plano to -1.50 D with a refractive target of -0.75 D, I’m clinically not seeing a significant drop off in distance vision or stereopsis. One of the pearls for success for us is that we have combined this lens with femtosecond laser technology to reduce astigmatism in the corneal plane. The Apthera lens can mitigate up to 1.5 diopters of astigmatism without any additional treatment. That’s why we use the Apthera lens combined with femto to minimize their astigmatism and maximize the potential of the lens.”

Reactions of Colleagues

“There are 10 of us in a large multi-specialty practice, and the advantage is that we're able to share our experience with new technologies. Because of the current limited market release for Apthera, my partners haven't yet had the opportunity to start implanting this lens, as I have.”

“When I attended the ASCRS Congress in San Diego earlier this year, I had the privilege to hear some of the doctors with international experience talk about the Apthera platform, which has been available for several years overseas. It was remarkable to hear that as providers are becoming more comfortable with it, they’re finding more and more patients who can benefit from it. I think there can also be an expanded role for Apthera where pupillary aperture therapy can be helpful to patients who have poor-quality vision with currently available lines of technology. I think there's an incredible future ahead for this type of technology to modernize monovision.”