High intraocular pressure was found at a medical check-up, and when he visited a local eye doctor, cataracts were also found; he first visited us without a referral letter in March 2023 for consultation about surgery.
Corrected vision was relatively good at 0.9p/1.2, but axial length was about 27.5 mm, a long eye, and as shown below he had entirely ordinary nuclear cataracts without special features, worse in the right eye, with refraction reaching extreme myopia beyond −10.0 D. He was considering surgery with multifocal lenses, but his intraocular pressure was somewhat high, around 21 mmHg, and OCT showed mild thinning of the nerve fiber layer, so there was also a glaucoma risk. We therefore said that multifocal candidacy would depend on visual field testing, and at the first visit he booked a surgery date and a visual field test before leaving.
The visual field test at the second visit showed overall reduced sensitivity, probably due to cataract (MD about −2.8), but no clear glaucomatous changes at present, a state that could be called preperimetric glaucoma. Considering the risk of future progression, we told him that monofocal lenses were the safest, and that if he really wanted multifocal lenses, Clareon Vivity, with almost no light energy loss, would be safer than the Clareon PanOptix that had been suggested. We did blood tests and gave him until the final preoperative visit to decide.
At the final preoperative visit he told us: "I'll retire soon and won't need computer distance. I want to prioritize golf, my hobby. With a monofocal lens I'd want it set for distance, and reading glasses are fine. In that case I accept that I won't be able to see the close distances I can see now." In the preoperative questionnaire, too, he wrote that distance (2 m and beyond) mattered most, intermediate (50 cm–1 m) second, and that he sometimes drives at night. So, given (1) emphasis on distance to intermediate, (2) occasions to drive at night, (3) reading glasses acceptable when needed, and (4) a glaucoma risk, after discussion we explained that Clareon Vivity was most likely to give the result he wanted, and he agreed to a plan setting the non-dominant right eye, with the more advanced cataract, slightly toward near at about −0.5 D, and the dominant left eye for emmetropia. Considering (4), the glaucoma risk and high pressure, we also decided to perform ab interno trabeculotomy at the same time, one of the minimally invasive glaucoma surgeries (MIGS: Micro-Invasive Glaucoma Surgery), a procedure that lowers pressure by incising the trabecular meshwork, the outflow channel for aqueous humor, the fluid inside the eye. This MIGS adds only 2–3 minutes to cataract surgery, and the cataract surgery fee is halved, so for people who meet the conditions, combined surgery has advantages both physically and financially.
First, surgery on the non-dominant right eye. The pupil dilated somewhat poorly and the iris was unstable, but lens removal went without problems. Considering measurements from the ORA system, an intraoperative wavefront aberrometer, and preoperative formula results, we inserted a lens targeting about −0.37 to −0.46 D by the preoperative formulas, incised the trabecular meshwork (MIGS), and the surgery was completed safely.
The next day there was mild hyphema from the glaucoma surgery, but uncorrected vision was 0.9 distance / 1.0 near, almost as predicted, and on day 4 it was 1.2p distance / 0.9 near, with subjective refraction of −0.375 D (objective −0.875 D). Our clinic usually discusses the target for the fellow eye at this point. In his case, we asked him to choose a target for the left eye more toward near, the same, or more toward distance than the right eye. Patients often cannot decide, so we ask at least something like "not more toward near" and order lenses in several powers. Postoperative refraction may of course keep changing, so in the end, on the day of left eye surgery, one week after right eye surgery, we ask patients to come early, measure the right eye's refraction again and test vision, reconfirm that their wishes have not changed, and then operate on the left eye. Recently the usefulness of same-day bilateral cataract surgery has been discussed, and depending on conditions and circumstances there are naturally people for whom it is a great advantage, so our clinic also performs it for those who wish. However, I am in my 50s myself, and thinking realistically about when I will have surgery, at present I would still want separate staged implants for each eye, to keep every possibility open.
To return to the topic: since his right eye saw relatively well at both distance and near, I expected him to want the same target for the left eye for binocular summation, but contrary to expectations he wished for the left eye to be set more for distance. Just before left eye surgery, to let him experience a 0.5 D shift toward distance, we tested with −0.5 D glasses on the right eye: 1.5 distance / 0.7 near; distance vision improved but near vision fell, as expected. Even so, he said, "With this vision, I'd like surgery aiming more toward distance as planned," so, as he wished, we set the target about 0.5 D toward distance.
In surgery on the dominant left eye, we naturally used the ORA system to create an appropriate difference between the eyes, adopted a lens power predicted before surgery to be slightly hyperopic at +0.14 D, again performed MIGS (ab interno trabeculotomy), and completed the surgery without problems.
The day after surgery, vision was 1.2 distance / 0.3 near, as if he could not use Vivity's near add at all, but on day 4 it was 1.5 distance / 0.8p near, almost the same as the preoperative simulation, and he was satisfied with good distance vision as requested (objective refraction −0.125 D).
At one month, perhaps owing to neural adaptation, so-called getting used to it or a learning effect, uncorrected vision improved in both eyes, to right eye: 1.2 distance / 1.2 near and left eye: 1.5 distance / 0.9p near; with the effect of the glaucoma surgery, pressure also fell to around 12 mmHg (see figure below), and he said he could live almost without glasses. However, Vivity gives the impression that postoperative vision fluctuates somewhat, and it often takes a little longer, 1–3 months, to stabilize. Moreover, since machine-measured objective refraction does not change during that time, with lenses whose power varies by zone, learning which part of the lens to look through may take time.
Because Vivity has its add in the center, people with small pupils may not make full use of the surrounding distance zone, and it is said that for people with small pupils, setting the target slightly toward hyperopia makes distance vision easier to secure. His pupils, however, were sufficiently large at 3.25–3.46 mm, eyes in which Vivity's function can work well. So, although the right eye saw well at distance after surgery, 1.2 as expected, he still wished for the left eye to see farther; this case made me feel the need to set targets considering not only patients' subjective wishes but also Vivity's add zone and add power.
2023.8.27