A check-up six months earlier had pointed out cataracts, and because blurring in his right eye was severe and inconvenient in daily life, he first visited us for consultation about surgery with multifocal lenses.
His eyes were long (high myopia), 28.5 mm right and as much as 29.6 mm left. I expected the nuclear cataract typical of high myopia, but the right eye had a cortical cataract with anterior and posterior subcapsular opacity reaching the pupillary area; as shown below, the cataract was so advanced that the OPD could not measure internal aberrations, and corrected vision had fallen to about 0.15–0.2.
In the preoperative questionnaire his priorities were near, intermediate, then distance, and he drove at night only very occasionally, so we recommended TECNIS Synergy, whose near focal distance is close.
Corneal astigmatism was mild but against-the-rule, so based on calculations including surgically induced astigmatism, the surgery was done with the toric TECNIS Synergy Toric.
The right eye dilated somewhat poorly, but the surgery was completed without problems, with none of the feared refractive error or axis misalignment; on day 4 uncorrected vision was very good, 1.2–1.5 at distance and 1.0 at near, but he said, "For the left eye, I'd like to see even closer." We explained that shifting TECNIS Synergy toward near tends to reduce distance vision, but he still wished for a nearer setting.
Right eye preoperative slit-lamp photo Right eye preoperative retroillumination photo
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Right eye postoperative slit-lamp photo Right eye postoperative retroillumination photo
The left eye had only slight corneal astigmatism, so the surgery was done with a non-toric TECNIS Synergy. As with the right eye, it dilated somewhat poorly, but the surgery was completed without problems; however, postoperative uncorrected vision was 0.6–0.7 distance / 0.9 near, poorer at distance than expected. Besides setting the target refraction toward near, postoperative refractive error, probably because the left eye was more than 1 mm longer, was also thought to be a factor.
We monitored the left eye's refraction for a week after surgery, but it did not shift toward distance and distance vision remained poor, so we explained to him that lens exchange was an option: if exchanging, within two weeks is best, and within a month at least, it can be done relatively safely.
He agonized considerably, but said, "I've got used to my right eye and can see closer now, so the poor distance vision in my left eye bothers me more after all. If possible, I'd like an exchange!" Since this meant a second operation on his eye, to make sure he would be satisfied this time, we had him simulate with several contact lenses to find how far to shift the power toward distance to improve distance vision without sacrificing near vision, explored the best "shift," and decided the power of the replacement lens.
The most uncertain factor in exchange surgery is the degree of adhesion between the lens and capsular bag. Forcibly peeling the lens away can tear the capsular bag, making it impossible to insert a new lens. In his case the exchange was early, two weeks after surgery, so we used the previous incision without making a new one, released the adhesions smoothly, and, as shown below, cut and removed the existing lens and replaced it with a new one.
Cutting the lens ⇒ Removal ⇒ Aphakic state
After surgery, just as simulated, uncorrected vision was 1.5 distance / 1.0 near, and he was very satisfied, saying, "I'm really glad I had the exchange!" One month after surgery, the right eye's vision had improved further at both distances, and he even said, "Come to think of it, I didn't need to set the left eye for near in the first place."
Exchange surgery becomes riskier than ordinary cataract surgery if a long time has passed since the first operation, but soon after surgery the lens can be exchanged relatively safely. It is not easy to decide on an exchange so soon after surgery, but if a change of power would help, we recommend telling your doctor your wishes without hesitation, before time passes unnecessarily. We will continue to strive to create an environment where it is easy to express your wishes.
2021.10.31