He had been told of cataracts at another clinic five years earlier and first visited us without a referral letter, asking, "Should I have surgery?"
Corrected vision was relatively good at 1.0–1.2, but, as shown below, he had dense cortical cataracts extending into the pupillary area, the fundus was poorly visible, and visual impairment not captured by acuity numbers alone was obvious.
We are often asked, "Should I have surgery?" but we can only answer that the timing of cataract surgery depends on the patient's wishes and the surgeon's skill. Of course this assumes there is visual impairment from cataract, but cataract surgery is surgery for people who want to improve their vision, even if it means having surgery, so even if measured acuity is poor, I believe people satisfied with their current vision do not need surgery. Of course, if it progresses too far, the risk of intraoperative complications also increases, but whether that is considered a risk depends on the surgeon. So, unless there are complications, our clinic does not actively recommend surgery; we limit ourselves to assessing whether surgery would improve vision, and leave the timing to the patient. In practice, therefore, some people wish to have surgery at an earlier stage than his, and some with more advanced cataracts than his do not.
At the first visit, internal higher-order aberrations (red frame in the figure below) on the OPD-Scan III, suggesting poor visual function due to cataract, were also high, so we told him that his reduced vision was due almost entirely to cataract and could be improved by surgery (= no other vision-reducing disease), that his eyes could withstand ordinary surgery, and that he was also a candidate for multifocal lenses if he wished, and asked him to return if he wanted surgery.
Ten days later he returned wishing to have surgery, saying, "Mountain climbing is my hobby and I want to see distant scenery clearly, but I also want to see the car navigation screen, and I sometimes drive at night. If possible I'd also like to see documents at hand." He had done various research himself and was considering LENTIS Comfort, a monofocal lens, and ALCON's Clareon Vivity, which at the time was little known even among general ophthalmologists. Being mildly hyperopic he used multifocal glasses, and said he could accept using reading glasses but wanted to avoid the risk of photic phenomena such as halos and glare, so in the end we had him choose among a monofocal lens, Eyhance and Vivity. At the time Vivity was not yet approved in Japan and the start of its use was undecided, but considering the possibility of using Vivity, which he had suggested, he booked surgery for April.
Fortunately, by the final preoperative visit two weeks before surgery, early use of Vivity had become possible. His corneal astigmatism was 0.75 D or less, and his pupils, 3.45/3.56 mm, were large enough for Vivity to function fully, so when we told him it could be used if he wished, he chose surgery with Clareon Vivity.
He said he had always seen near with the right eye and distance with the dominant left eye, and he wished to start with the non-dominant right eye, which had greater visual impairment. Since the real-world range of clear vision beyond Vivity's specifications was not yet precisely known, I was slightly reluctant to set it near-dominant from the start (as it was not impossible that near could be seen even when set exactly for distance without sacrificing distance), but we gave priority to reliability and set a near-dominant target for the right eye. For preoperative lens power calculation, we went into surgery referring to results from several formulas, shown below, and to results for the former AcrySof Vivity, which is already optimized.
In right eye surgery, perhaps from nervousness, he tensed up and his eye tended to move, but cataract removal went without problems. As shown above, his corneal power was 41.82 D, flatter than usual, so we performed intraoperative wavefront aberrometry with the ORA system. The material had changed from AcrySof to Clareon, and the lens had been released first in Japan with few lenses yet used worldwide, so I was concerned about the reliability of the optimized lens constant; during surgery we therefore compared three results to choose the lens power: Clareon Vivity, AcrySof Vivity, and the Clareon monofocal lens on the same platform.
Uncorrected vision the day after surgery was 1.5p distance / 0.8 near, near poorer than expected, but by day 4 and one week, with a slight myopic shift as targeted and perhaps also some adaptation, he was satisfied with good vision at both distances, 1.2 distance / 1.2 near. More than a month after surgery, neither objective refraction nor uncorrected vision has changed.
From our experience with Vivity in several cases, since Vivity is an extended depth of focus (EDOF) lens, there seems to be a difference of up to about −0.50 D between objective refraction measured by the refractometer and subjective refraction during vision testing. The same is true of the EDOF TECNIS Symfony and the continuous-focus TECNIS Synergy, which measure about 0.75 D more myopic; perhaps because of their diffractive structure, the deviation is almost constant (a refractometer reading of −0.75 D is actually 0.00 D). With Vivity, which is not diffractive and whose power varies by zone, my impression is that the measured value varies with the proportion of the pupil occupied by the central wavefront-shaping zone at the time of measurement (the same is true of LENTIS Comfort). So subjective vision testing cannot simply trust the refractometer's refraction, and, for the reasons above, the deviation is not constant and seems to vary between individuals, so this time, to avoid misleading anyone, we have deliberately not stated the target and postoperative refraction.
Next, the left eye. Since the right eye had good vision at both distances, I personally thought the left eye would have the same target, but he said, "I've had enough near now. Mountain climbing is my hobby and I want to see far distance close to infinity clearly, so for my dominant left eye, even if near vision drops, I want to target 0.00 D, even further toward distance," and we proceeded on that basis.
During surgery we could also refer to the right eye's ORA measurements, so we expected to operate more reliably and precisely, and, as he wished, we chose the power with relative confidence aiming exactly at 0.00 D for distance.
After left eye surgery, the result was on target, with uncorrected vision of 1.5 distance / 0.7, and he was satisfied with distance vision; personally, though it may also depend on pupil size, I felt that the range of clear vision was just as per the specifications.
Clareon Vivity tends to be compared with TECNIS Symfony in terms of range of clear vision and EDOF, but it does not seem to show the astigmatism-correcting effect seen with the diffractive Symfony (also as per the specifications), and with its structure of power varying by zone, it struck me as a lens closer, if anything, to LENTIS Comfort. From its advance reputation, I had expected a lens with broad candidacy, relatively easy for anyone to use, like TECNIS Symfony when it appeared, but patients' preoperative conditions, including preoperative refraction, pupil size and corneal astigmatism, are readily reflected in the results, and I felt that careful candidacy judgment is needed, not just for Vivity.
He was our clinic's first Clareon Vivity case, so to make up for my lack of experience with it, I researched carefully, and the surgery involved strict candidacy judgment as well as backup plans; I am relieved that, in the end, we could provide vision that satisfied him. I learned a great deal myself, and the case also made me appreciate the strengths of diffractive lenses anew, so I thank the patient for his courageous choice of surgery with a new lens.
He was relatively young, in his 50s, so next time I would like to present a case of a patient in her 70s. This will skew the lenses featured, but to provide information we will continue publishing Vivity cases for a while; thank you for your understanding.
2023.6.11