HAVE YOU EVER HAD PATIENTS who were really frustrated with their progressive add lenses? Have you wondered why your multifocal contact lens wearers won’t wear their lenses, even when their vision measures 20/20? Have you had a patient try a presbyopia therapeutic drop and fail to ever use it again? What about premium intraocular lens (IOL) patients who are incredibly unhappy with the investment they made because their expectations just weren’t met?

You are not alone. These have all happened to every eyecare provider, including myself. What’s really going on in these scenarios and what can we do to set our patients and ourselves up for success?

The human visual system is incredibly complex and extremely adaptive. The brain has the ability to respond to input from the outside world and rapidly filter out “noise.” This process of reacting when something disturbs vision is called neuroadaptation. Neuroplasticity is the process by which the brain can reorganize its structures, functions, or connections through changing how the nervous system responds to stimuli and “neuroadapts”¹—in simple terms: new image, same brain. Neuroplasticity does decrease through the aging process² and should be considered when matching patient desires with current technology, along with setting patient expectations.

HOAs

How do we know what to discuss, and when, with patients? Let’s talk about higher-order aberrations (HOAs) for a moment as these can play a role in patients’ visual quality. Lower-order aberrations, such as myopia, hyperopia, and astigmatism, are what we traditionally correct with current technology. HOAs include coma, trefoil, and spherical aberrations. Normally the retinal image quality due to HOAs goes unnoticed.³

However, when they change or go beyond the normal 7% due to surgery or a disease process, they can be quite bothersome to patients.⁴ Many factors affect HOAs, including anatomical factors, such as tear film and keratoconus.⁵ Pupil sizes between 2mm and 5mm give the best visual acuity. Pupils smaller than 2mm can degrade vision due to diffraction, and pupils larger than 5mm can reduce vision due to spherical aberrations.⁴

The relationship between the cornea and lens can change HOAs, as can aging lenticular changes.⁴ Refractive error amounts can also contribute to HOAs and are now thought to be due more to the axial length of the eye.⁴ This matter is currently undergoing intense research regarding how to slow axial length changes, in the case of myopia, by correcting a peripheral hyperopic defocus on the retina to slow growth.⁴ I’ve greatly simplified this conversation for our purposes regarding neuroadaptation.

Neuroadaptation

Knowing this information, how do we apply it clinically? Patients have no understanding of neuroadaptation. They truly expect to “just see.” Intentional conversations and assessment of the patient are paramount for successful outcomes. First, ensure that all patients are screened and treated for dry eye disease.⁵ Doing so establishes best visual outcomes regardless of whether the patient is a candidate for spectacles, contact lenses, therapeutic drops, or surgery, for their presbyopia. If the ocular surface is not maximized, any type of correction will have limited successful outcomes.

Next, teach patients that their visual system will need to undergo neuroadaptation and that the timeline varies from patient to patient, and depends on the type of correction. I have found it incredibly helpful to discuss with patients that there will be a period during which their brain adjusts to seeing a new image.

Third, establish what success looks like for you and your patient. I have one very smart colleague who defines success in an unconventional way. He cut off his near point cards at 20/40. This is what you and I consider success and completely functional vision. By doing this, he doesn’t entice patients to wonder why their correction can’t make them see 20/30 or 20/20. Instead, he defines success for the patient.

I’ve listed below best practices about neuroadaptation and setting proper expectations.

SPECTACLES:

• Spectacles are easier with smaller powers; therefore, I encourage patients to fill prescriptions for progressive addition lenses when the add power is small.
• Ten to 14 days is the typical time to neuroadapt.
• Patients should try to wear every new prescription every day to help build pathways.
• Limit switching back and forth from habitual prescriptions and new prescriptions.

CONTACT LENSES:

• Let the patient wear the prescription, and limit in-office changes to fewer than 2.
• Center near designs take longer.
• The larger the anisometropia, the longer it takes.
• Neuroadaptation might take only a week, but it may take a few months, depending on the contact lens design, due to the brain seeing simultaneously focused and defocused images.

THERAPEUTIC DROPS:

• Remind patients that this is depth of focus vision, meaning clarification not magnification.
• Have patients use the drops every day for 2 weeks based on findings that depth of focus gradually increased over 14 days, possibly suggesting a neuroadaptation response similar to what has been observed with enhanced depth of focus IOLs.^6,7 The findings showed a peak at 2 weeks.

SURGICAL PATIENTS:⁸

Careful history

• Rule out significant ocular pathology.
• Screen out patients with high expectations.
• Avoid young patients with great preop visual acuities.
• Avoid eyes with large pupil size.
• Avoid patients with type A personalities.

Pre-op considerations

• Comprehensive medical/ocular history examination
• Contrast sensitivity
• Refraction
• Optical coherence tomography of the macula
• Topography
• Pupillometry/angle kappa

Patients can experience any of the following postop, which can last up to 6-12 months. Rarely, in some patients, the brain will never adapt.

• Halos/glare
• Reduced contrast sensitivity
• Positive/negative dysphotopsias
• Shadows
• Waxy vision
• Residual ametropia
• Posterior capsular opacification

Armed with all this information, we as prescribers can be completely transparent about expectations. We must remember that patients don’t know what they don’t know. The more time spent up front with the patient asking the right questions, the less chair time later with the patient trying to backpedal and establish what success should look like. Remember: any discussion before a problem arises is an explanation; any discussion after is an excuse. Utilize a lifestyle questionnaire to help you choose patients wisely, establish what the patients want to accomplish with and without spectacles, or make them less spectacle dependent.

The Presbyopia Opportunity

Presbyopia is a journey, both for us as eyecare providers and for our patients who spend half their lives presbyopic. When you look at the rates of our patients utilizing multifocal contact lenses, therapeutic drops, and premium IOLs, there is more opportunity. The current technology accessible today gives patients a truly customized approach that is unprecedented. Remember, there isn’t just one solution for presbyopia, leverage all the technology to empower patients with presbyopia to utilize different modalities for their situations. Set up your presbyopia conversations for successful outcomes with these pearls. Connect patients with the right technology, help patients understand the connections that their brains need to make that technology work, and stop the presbyopia disconnect! ■

References

1. Mateos-Aparicio P, Rodriguez-Moreno A. The impact of studying brain plasticity front. Cell Neurosci. 2019;13:66.
2. Alió JL, Pikkel J, eds. Multifocal Intraocular Lenses: The Art and the Practice. Essentials in Ophthalmology, Cham, Switzerland: Springer International Publishing; 2019.
3. Artal P, Chen L, Fernández EJ, Singer B, Manzanera S, Williams DR. Neural compensation for the eye’s optical aberrations. J Vis. 2004;4(4):281-287.
4. Suliman A, Rubin A. Corrigendum: A review of higher order aberrations of the human eye. Afr Vis Eye Health. 2019;78(1):1-8.
5. Rhee J, Chan TC, Chow SS, Di Zazzo A, Inomata T, Shih KC, Tong L. A systematic review on the association between tear film metrics and higher order aberrations in dry eye disease and treatment. Ophthalmol Ther. 2022;11(1):35-67.
6. Lievens C, Kannarr S, Pack W, Zhang Z. Extended depth of focus from AGN-190584 in GEMINI 1 and GEMINI 2 pooled phase 3 studies. Invest Ophthalmol Vis Sci. 2022;63(7):F0428 (meeting abstract).
7. Alió JL, Pikkel J, eds. Multifocal Intraocular Lenses: The Art and the Practice. Essentials in Ophthalmology, Cham, Switzerland: Springer International Publishing; 2019.
8. Rampat R, Gatinel, D. Multifocal and extended depth-of-focus intraocular lenses in 2020. Ophthalmology. 2021;128(11):e164-e185.