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Digital Supplement | Sponsored by NIDEK

Overcoming the Last Barrier to Good Visual Outcomes

Thanks to advancements in surgical technique, IOL technology, and IOL calculations, we have overcome the major issues of cataract surgery and are inching toward refractive precision. Now, in order to further refine our outcomes, the small things matter: the effects of dry eye disease (DED), the integrity of the capsule (including posterior capsular opacification [PCO], capsular block syndrome, capsular phimosis, IOL shift, decentrations, and dislocations), and any issues with the vitreous. Herein, I will focus on treating common PCO.

PCO

If we do enough cataract surgery, we will come across PCO, a condition that decreases vision and contrast sensitivity and causes glare. Patients think their cataract has come back again. In my experience, PCO affects multifocal IOLs much earlier than monofocal ones. The standard treatment is an Nd:YAG laser capsulotomy, of which there are no decent alternatives now.

LASER CAPSULOTOMY

Settings

In my practice, I use the YC-200 S plus Ophthalmic YAG and SLT Laser System (NIDEK). I start with a 1.7-mJ single burst with a 100-µm posterior offset. I focus the laser’s aiming beam vertically, although one can certainly use it in horizontal or oblique directions. For all my Nd:YAG laser capsulotomies, I now include a little bit of Nd:YAG membranectomy.

Procedures

There are many different shapes in which we can perform an Nd:YAG laser capsulotomy: round, postage stamp, or Christmas tree, for example. I generally don’t use these shapes, because they produce a flap that may affect the vision. We want to avoid creating especially small, free-floating pieces of posterior capsule. I like a cruciate shape (like a kite or a diamond; Figure 1), because this is the best way to avoid free-floating fragments of posterior capsule. I make the capsulotomy as large as the optic allows, almost up to the optic’s size. A capsulotomy that is too small will underutilize the optics of a modern premium IOL—most of the premium IOLs implanted today feature optics that extend all the way to their edges, so we want to make full use of that. Yet, we don’t want the capsulotomy to be too large, which would compromise the stability of the IOL. Over a few months, what begins as a diamond-shaped capsulotomy will become more oval and approach a round shape within 6 months, but it will still overlap the optic.

Figure 1. Dr. Fam favors a cruciate shape for capsulotomies. They will grow more oval over time, yet still overlap the optic of the IOL.

Eyes that are contraindicated for a capsulotomy are those that cannot fixate or that have preexisting ocular inflammation. We must control the inflammation first.

IOL Pitting

Capsulotomies generally carry very low risk. IOL pitting is something that is more frequent than we care to admit; it happens when the laser’s energy is focused too close to the IOL. Generally, IOL pitting does not affect patients’ vision. Of course, we want to avoid pitting along the visual axis, so we must offset the laser so it is not striking exactly on the capsule. Many Nd:YAG lasers, including the YC-200 S plus, allow 500-µm offsets anteriorly to posteriorly in 25-µm steps. The recommended offset is 125 µm posteriorly, but I prefer a 100-µm offset, because it is satisfactory to reduce pitting and, at the same time, it’s much more effective.

ENHANCING OUTCOMES WITH PRECISION YAG LASER

Although cataract surgery has significantly advanced to deliver reliable and consistent visual outcomes, challenges with the postoperative capsule and vitreous membrane persist. However, by employing precise Nd:YAG laser procedures using advanced devices designed for accuracy, these issues can be effectively managed, further enhancing the overall success of cataract surgery.

author
Han Bor Fam, MD
  • Senior Consultant, Cataract & Anterior Segment Surgery and Refractive Surgery, Tan Tock Seng Hospital, Singapore
  • Han_ Bor_Fam@ttsh.com.sg
  • Financial disclosures: Consultant (Alcon, Carl Zeiss Meditec, Johnson & Johnson Vision); speaker (NIDEK)

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