Improved depth of field makes the target easier to hit

Special Ophthalmology Times®

I recently started implanting the Tecnis Eyhance IOL (ICB00, Johnson + Johnson Vision), a new toric monofocal / monofocal IOL with an optimized power profile.

It quickly became our default lens choice for any patient undergoing premium cataract surgery who is not a candidate for presbyopia correcting IOL.

In our practice, this includes anyone undergoing femtosecond laser surgery with correction of astigmatism (toric IOL and / or arched incisions).

Optical bench tests have shown that the ICB00 is comparable to the Tecnis monofocal IOL, model ZCB00 in terms of distance image quality, while providing better simulated intermediate vision.1

Reach the distance target
The biggest advantage of using the lens, for me, is being able to meet the expectations of far vision patients.

We know that high quality far vision requires that the refraction result be within 0.5 D of emmetropia, with minimal residual astigmatism. Yet ophthalmologists only achieve this goal about 70% of the time.2

The ICB00 lens is designed to extend the depth of field slightly. This increase is not as large as other presbyopia and extended depth of field correcting lenses, but is sufficient to provide a wider landing zone.

If the patient has a result of +0.25 D to +0.50 D, he will see well at a distance. If the result is –0.25 D to –0.50 D, they will see well from a distance and may have somewhat better intermediate visual acuity.

So far our distance results have been excellent. In the first 42 eyes I implanted the lens in, 10 had conditions such as diabetic retinopathy or an epiretinal membrane (ERM) that limited visual potential.

Of the 32 eyes with no other ocular pathology (mean patient age, 74), the mean distance acuity was 20/25.

Shallow depth of field can also help mask small amounts of residual astigmatism; studies with other IOLs have shown that greater depth of field improves tolerance to astigmatism.3-5

While useful in many cases, a patient’s improved tolerance to astigmatic error could be particularly beneficial for surgeons who do not have intraoperative aberrometry, digital staining, or a femtosecond laser to help them. position the toric lenses precisely on the stiff axis.

I have found the wider landing zone particularly useful for eyes where calculating the power of the IOL is difficult.

For example, a patient with a very large ERM had uncorrected distance acuity of 20/30 on day 1 after surgery and claims to no longer even notice the central distortion.

It is difficult to predict the results of refraction in such eyes because the ERM pulls on the retina and can make the patient more myopic than expected.

In addition, if the patient subsequently needs a membrane peel, it can cause the retina to sit about 100 µm further back, changing the refraction down to 0.25 D.

Thanks to the slight extension of the depth of field of the ICB00 lens, I can offer RME patients good vision now and allow them to retain it later, even if they eventually need a skin peel. membrane.

An IOL with a boost

Preclinical studies have shown an improvement over monofocal Tecnis thanks to a defocus of –1.00 to –2.00 D, ie a gain of approximately 0.1 logMAR.1

Historically, we have not measured intermediate or near vision in patients with monofocal IOLs, but in patients with the ICB00 lens, we check for near vision at a functional distance of approximately 20 inches.

At this distance, 97% of patients have a Jaeger (J) score of 10 or more.

A few patients showed up for postoperative appointments with surprisingly good near vision.

One of these patients, with a hyperopia of +4.0 D, had enjoyed good vision after LASIK, but since the onset of presbyopia, he had difficulty seeing well at any distance without correction.

He wore contact lenses but, as an avid windsurfer, he was unhappy that he couldn’t see well if he lost a lens or if the wind irritated his eyes.

We implanted the ICB00 lens in both eyes. At 1 month, he could see 20/20 and J5 in one eye and 20/20 and J1 in the other. This is an exceptionally good result, and certainly not what I would promise patients before the operation.

It is possible that the high power of the lens implanted in this case (28 D) or some corneal aberrations from the previous LASIK procedure contributed to the result.

As we gain more experience with this lens, we can better understand which eyes are likely to perform better than average.

Being designed to provide a small extension of the depth of focus, the ICB00 can also make the ICB00 a good lens to use when a monovision target is planned. The mini-monovision works well enough for tall people with long arms.

In my practice, this goal fills a gap. I expect it to replace standard monofocal and toric monofocal IOLs in about 40% of my cases.

About the Author

Carlton Yuen, MD
E: [email protected]

Yuen practices at Aloha Vision Consultants in Honolulu, Hawaii. He served as chairman of the ophthalmology department at Kuakini Medical Center in Honolulu and head of the ophthalmology division at Hawaii Medical Center West in Ewa Beach. He is a consultant for Johnson + Johnson Vision.

Caitlin Yuen is an ophthalmic assistant at Aloha Vision Consultants who compiled patient data from Tecnis Eyhance.


The references

1. Alarcon A, Cánovas C, Koopman B, Weeber H, Auffarth GU, Piers PA. Improve the intermediate vision of monofocal intraocular lenses using higher order aspherical optics. J Thrust refraction. 2020; 36 (8): 520-527. doi: 10.3928 / 1081597X-20200612-01

2. Ma J, El-Defrawy S, Lloyd J, Rai A. Precision of intraoperative aberrometry prediction versus preoperative biometric formulas for the selection of intraocular lens power. Can J Ophthalmol. Published online July 22, 2021. doi: 10.1016 / j.jcjo.2021.06.024

3. Carones F. Residual astigmatism threshold and patient satisfaction with bifocal, trifocal and extended field of vision intraocular lenses (IOL). Open J Ophthalmol. 2017; 7 (1): 1-7. do I:10.4236 / ojoph.2017.71001

4. Ang RE. Comparison of tolerance to induced astigmatism in pseudophakic eyes implanted with small aperture, trifocal or monofocal intraocular lenses. Clin Ophthalmol. 2019; 13: 905-911. doi: 10.2147 / OPTH.S208651

5. Ben Yaish S, Zlotnik A, Raveh I, Yehezkel O, Belkin M, Zalevsky Z. Omnifocal intraocular lens with increased tolerance to decentration and astigmatism. J Thrust refraction. 2010; 26 (1): 71-76. doi: 10.3928 / 1081597X-20101215-12

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