By request, here is our third cataract surgery case in a young patient.
About seven years ago, while I was working at a university hospital, I operated on his right eye only, using TECNIS Multifocal with a +4.0 D add, for poor vision due to atopic cataract; this time he returned after a long interval because reduced vision and blurring in his left eye had worsened.
When his right eye was operated on he was still in his 20s, and since it was single-eye surgery and he had high myopia, I remember discussing at length, including the pros and cons, whether to use a monofocal or multifocal lens, and he chose a multifocal lens. Atopic cataract is generally technically difficult to operate on, and is often accompanied by fundus problems such as weak zonules and peripheral retinal tears; at that time there was an even stronger tendency than now to regard multifocal lenses as unsuitable simply because a cataract was atopic. Even so, he found it unacceptable to suddenly become presbyopic in the right eye alone in his 20s with a monofocal lens, and, since the other eye might also need surgery within a few years, he wished for surgery with TECNIS Multifocal with a +4.0 D add; fortunately, to our relief, he is still satisfied with his right eye's vision at both distance and near.
And this time, as expected, an atopic cataract had developed in the left eye: corrected vision, 1.2 in August 2018, had fallen to 0.3–0.4, and, as shown below, the characteristic anterior capsule fibrosis had progressed not only in the pupillary area but in places almost to the peripheral equator. Age-related cataracts usually progress little by little, over years, but it is not unusual for atopic and traumatic cataracts, once they start, to progress over months.
In surgery, the surface of the cataract (anterior capsule) is first opened in a circle about 5.5 mm across (anterior capsulotomy); hard fibrotic areas can obstruct this, so the capsulotomy cannot be completed well, leading to complications. Also, although it does not usually affect vision, fibrotic anterior capsule, that is, some opacity, remains in the periphery outside the 5.5 mm, so personally I think it is safer to have surgery before anterior capsule fibrosis spreads to the periphery.
The figure below shows the OPD-Scan III results. Internal higher-order aberrations (lower left) were very large at 1.124 µm, and the simulated image of blur from internal aberrations (upper right) is smeared beyond recognition, suggesting the cataract caused considerable difficulty seeing. Also, both corneal higher-order aberrations (lower left) and corneal spherical aberration (lower middle) are small, so he could be judged a candidate for multifocal lenses, and since there was 2.09 D of with-the-rule corneal astigmatism, with the cornea bulging top and bottom, we can also see that a toric lens was needed to bring out better visual function (*for details of the OPD-Scan III, see Case #48).
For the lens, since the right eye has TECNIS Multifocal, we recommended TECNIS Synergy for the left eye, on the same platform and available in a toric version, and he agreed without hesitation.
In surgery, by using special scissors on the fibrotic anterior capsule, the capsulotomy succeeded, the zonules were not very weak, and we completed the surgery safely. Also, for his long axial length his cornea was steep (high corneal power), raising concern about postoperative refractive error, but since we chose the left eye's lens power taking into account the postoperative refractive error in the right eye surgery, there was almost no error from the target refraction in the left eye.
Uncorrected distance vision, 0.1 before surgery, improved greatly to 1.5 distance / 1.5p near after surgery, and he was very satisfied that the cloudy view in his left eye had cleared. The figure below shows fundus photos before and after surgery: before surgery the details were unclear, but after surgery even the retinal vessels can be seen clearly. Likewise, his own vision improved greatly, and fundus examinations can now be done accurately.
Personally, I was interested in the difference in vision between TECNIS Multifocal in the right eye and TECNIS Synergy in the left, so I took the liberty of asking him about various details after surgery. What surprised me first was that, although TECNIS Multifocal, with its +4.0 D add, has on specifications the strongest add among current multifocal lenses, with focus at 30 cm, he answered that near vision was almost the same in both eyes. He also said that distance to intermediate was clearer with Synergy, which felt brighter overall at every distance than TECNIS Multifocal, but that photic phenomena such as halos, glare and starbursts were stronger with Synergy. However, the differences were only noticeable when covering one eye at a time, and in everyday life with both eyes he said the difference between the eyes did not bother him at all.
His right eye also had corneal astigmatism, but at that time no toric multifocal lens was available at the university hospital, so TECNIS Multifocal was used with an incision on the steep meridian (the left eye surgery also used an incision from above on the steep meridian, so this patient, with deep-set eyes, had to keep his chin raised in a somewhat uncomfortable position). Consequently, residual astigmatism is larger in the right eye than in the left eye with toric Synergy, which may weaken the right eye's TECNIS Multifocal vision.
So one cannot generalize, but since he felt that near vision was almost the same with TECNIS Multifocal with a +4 D add and the continuous-focus TECNIS Synergy, TECNIS Synergy seems, as its reputation suggests, suited to people who prioritize near vision. It was also a case that made me feel I can confidently recommend TECNIS Synergy to people torn between TECNIS Multifocal and TECNIS Synergy, as long as they don't mind photic phenomena at night.
2022.01.01