She first visited us for consultation about surgery with a multifocal lens in one eye.
She had had LASIK in both eyes, and in the right eye also a corneal inlay (KAMRA Ring) as presbyopia treatment; this time she came because the cataract in her left eye, pointed out two to three years earlier, had progressed.
A corneal inlay is refractive surgery in which a small, thin ring-shaped film is inserted into the corneal stroma to extend depth of focus through a pinhole effect (the same principle as seeing better when you squint). It is normally done only in the non-dominant eye; disadvantages include things looking darker at night and the ring hindering prompt, adequate treatment if fundus disease develops, but an advantage is that, like an ICL, it can be removed.
Her right eye had +1.0 D of hyperopia and strong astigmatism of −3.5 D, but thanks to the corneal inlay she subjectively saw 1.0 at distance and 0.8 at near uncorrected, so, as she wished, we planned surgery on the left eye only.
The left eye had a cataract mainly of cortical opacity, with a white rim of pseudoexfoliation material at the pupil margin (see arrow below). Such patients often also have poor pupil dilation, weak zonules and glaucoma, which raise the difficulty of cataract surgery, that is, the risk of complications. As expected, her pupil dilated poorly, to about 4.0 mm (normally pupils open to about 8.0 mm, and opening beyond 6.0 mm, the diameter of the artificial lens, is safer), so we told her that additional procedures to enlarge the pupil, or insertion of a capsular tension ring (CTR) to reinforce the zonules, might be needed.
As for the lens, having had LASIK and a corneal inlay, she was highly conscious of quality of vision, and with the goal of living without glasses she wished for surgery with a multifocal lens.
As the OPD-Scan III results below show, despite her LASIK, both corneal spherical aberration and higher-order aberrations were not very large, so we judged her a candidate for multifocal lenses. However, we explained that, after LASIK, the risk of postoperative refractive error cannot be made zero, and the surgery was performed with Clareon PanOptix, which we considered overall the most reliable.
In surgery, the pupil did indeed dilate poorly, so for safety we made small incisions at the pupil margin, which secured a sufficient surgical field as shown below, and we completed the surgery without hindering postoperative pupil constriction.
For lens power, we narrowed the choice to three powers from the results of seven post-LASIK IOL power formulas, including the EVO Formula and Barrett True K with TK, and finally chose the lens power based on intraoperative wavefront aberrometry (ORA system).
Thanks to intraoperative wavefront aberrometry (ORA system) and the advance preparation, the feared refractive error did not occur after surgery; spherical equivalent was −0.375 D and subjectively −0.125 D, almost emmetropic, and she was very satisfied with good vision of 1.2 distance / 1.2p near uncorrected. Also, since her right eye is used to how it sees with the corneal inlay, we recommended that when she eventually has surgery on it, the inlay be left in place, that is, preserving the cornea's extended depth of focus, and that surgery be done with a monofocal lens.
Patients are often torn between TECNIS Synergy and PanOptix and ask us about their differences and features. We explain three points: (1) on specifications, the near focal distance is 30–35 cm for TECNIS Synergy and 40 cm for PanOptix; (2) photic phenomena such as halos, glare and starbursts are milder with PanOptix than with TECNIS Synergy; and (3) PanOptix allocates more light energy to distance (about 50%) than TECNIS Synergy.
Until now, in line with the lens specifications, PanOptix near vision was mainly measured at 40 cm, but with the arrival of TECNIS Synergy it has also been measured at 30 cm for comparison, and recent reports say that PanOptix's 30 cm vision is almost the same as TECNIS Synergy's. However, a patient of ours with TECNIS Synergy in the right eye and PanOptix in the left said near was easier to see with TECNIS Synergy, so TECNIS Synergy may suit people with a preoperative refraction of around −3.0 to −3.5 D who originally saw near at 30 cm comfortably, while PanOptix may be better for people who want to prioritize good-quality distance vision for driving or sports such as golf.
Also, from the surgeon's side, choosing and using the lens, TECNIS Synergy is a lens whose power selection is demanding, that is, difficult, but which secures a wide range of clear vision when matched exactly, while PanOptix is a lens with broad candidacy that is easy to handle, whose power can be chosen with almost the same feel as a monofocal lens set for distance (this is purely my personal impression).
With the arrival of new lenses, various new findings are also coming to light. Specifications are of course very useful as one indicator, but when a lens is actually placed in a human eye, I think it may or may not deliver functions that specifications alone cannot measure. However, as surgeons we cannot recommend lenses in the hope of uncertain benefits, so with that understanding we recommend choosing a lens by matching its features against your own priorities for quality of vision.
2022.07.10