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Refractive Surgery | Nov 2010

Setting Patient Expectations

Two case studies illustrate the importance of pupil size with phakic IOLs.

This article presents results of two highly myopic patients implanted with the Visian ICL (STAAR Surgical, Monrovia, California). Despite the fact that both patients were contact-lens intolerant and that their corneal thickness, pupil size, anterior chamber dimensions, and degree of myopia were similar (Table 1 and Figures 1 through 4), their postoperative satisfaction differed, demonstrating that patient selection is essential for successful refractive surgery outcomes.

The refractive treatment options available to contact-lens–intolerant patients who want spectacle independence include LASIK, some form of laser surface ablation, refractive lens exchange (RLE), and phakic IOLs. In our case examples, LASIK was not ideal given the patients' rather thin corneas; surface ablation was not advisable, as it could lead to haze and higherorder aberrations; and RLE was not the best option because both patients had high myopia, which would be a risk factor for vitreous alterations and subsequent retinal detachment after RLE. Additionally, RLE with a monofocal IOL causes loss of accommodation, which would cost both these young women their natural ability to focus at every distance and would necessitate reading glasses. RLE with multifocal or accommodating IOLs was not advised because it would worsen their near vision.

Phakic IOLs were our best option in both cases because they provide better visual outcomes and stability. Phakic IOLs also produce less higher-order aberrations—hence less visual disturbances at night—than keratorefractive surgery in high myopia.1 They also have a lower risk of complications compared with RLE.1 The procedure is reversible, and, if needed, explantation can restore the patient's vision to its preoperative state. Long-term safety concerns with phakic IOLs include endothelial cell loss, cataract formation, secondary glaucoma, iris atrophy, and dislocation.

One concern we had was that these patients' large mesopic pupil sizes could yield some glare and halos at night. We talked thoroughly with both patients, and both agreed to receive phakic IOLs and signed the informed consent. In the second case, the patient was thrilled with the prospect of spectacle independence. She called me a “wonder doctor” before she even had surgery.

CASE STUDIES
After performing bilateral Nd:YAG iridotomies at the 10- and 2-o'clock positions, we proceeded with ICL implantation with a 1-week delay between eyes. The ICLs were implanted through 3-mm self-sealing temporal corneal incisions.

The first patient (Figures 1 and 2) was happy with her result. Three years after the operation, her visual acuity is 20/20 uncorrected in both eyes. She did not report any night glare or halos. ICL position and vaulting were normal.

The second patient was also delighted with her result the day after surgery. Three days later, however, she started complaining about glare and night vision problems. These symptoms persisted, and she postponed surgery on the second eye. Upon examination, we confirmed correct positioning and vaulting of the ICL. But due to the patient's large pupils in the undilated state, the edge of the ICL could be seen with the Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany; Figure 3) and with mesopic pupil imaging with the OPD Scan (Nidek, Gamagori, Japan; Figure 4). We explained the origin of these complaints and told her that these symptoms tend to improve over a few months. One year later, she had yet to schedule surgery on the other eye because of persisting glare and halos. After trying different strategies, including diluted pilocarpine and brimonidine eye drops, all of which were unsuccessful, explantation was suggested. However, the patient liked her spectacle-free vision in daylight so much that she refused, and 18 months after surgery on the first eye she asked for ICL implantation in her fellow eye. Three years after surgery on the first eye, her UCVA is 20/20 in both eyes. Two years after surgery on the second eye, she is still considering ICL explantation because of glare and halos.

PATIENT PERCEPTIONS
It is striking that, although these were comparable patients, their perceptions of the ICL surgery were different. The first patient had an agreeable postoperative course and is satisfied with her choice; the second patient experiences almost unbearable glare and halos. How could we have predicted the patients' postoperative experiences given their preoperative expectations?

The major difference between these two patients is their personalities. Preoperatively, the first patient reacted normally, whereas the second patient was over-enthusiastic. Maybe patients with the latter personality trait focus on adverse events, exaggerating their perception of visual symptoms until they become hard to live with. Preoperative depressive symptoms can be a significant contributor to patient satisfaction after refractive surgery, as Morse and colleagues showed with LASIK.2 It is our task as doctors to initiate thorough preoperative discussions of these possibilities. In our clinic, all refractive surgery patients undergo preoperative assessment with the surgeon so that we can understand what the patient expects of surgery and discuss the possibilities and solutions for their refractive errors, including side effects. We explain that these side effects cannot always be predicted, nor can we predict which patient will tolerate these symptoms.

It might be that this level of confidence between doctor and patient is the reason that the second patient entrusted us with ICL implantation in the fellow eye. Would the period of adaptation to her night vision problems have been shorter if we had performed bilateral same-day ICL implantation? Probably. But she would still complain of glare and halos, as these symptoms persisted 2 years after ICL implantation in the second eye. We also have to consider that she might not be willing to face a possible bilateral ICL explantation.

We should be cautious of treatment options for patients with large pupils. Despite the second patient's night vision problems, she did eventually ask for implantation of the ICL in her other eye, suggesting that the gains in daylight visual quality outweighed her night vision problems.

DISCUSSION
Given that our patients' pupil diameters were larger than that of the ICL, some glare and halo was to be expected— and disclosed preoperatively to the patients—because the edge of the ICL can give rise to optical effects. In large studies of phakic IOLs, night vision symptoms have varied from 44% to 58%.3,4 The advantage of phakic IOL implantation is its reversibility.

In the case of LASIK, it is argued that pupil size does not correlate with symptoms of glare and halos;5 however, excimer laser surgery in high myopia can induce these symptoms, mostly due to induction of spherical aberrations. This effect is said to be independent of pupil size. Today's ablation profiles have smooth transition zones, larger effective optical zones, and therefore a lower risk of glare and halos.6 We suggest that one should reconsider or at least discuss LASIK for myopia up to -10.00 D, especially in patients with thick corneas and large pupils. It seems difficult to predict which patients will be disturbed by glare and halos, even among those with large pupils.

CONCLUSION
These two cases illustrate the difficulties a surgeon faces when selecting patients for refractive surgery and proposing a certain procedure for a certain patient. A good patientdoctor relationship helps you to discuss problems, even postoperatively, and keeps the patient in your clinic rather than pursuing a possible lawsuit against you.

Guy Sallet, MD, FEBOphth, practices at Ooginstituut, Aalst, Belgium. Dr. Sallet did not provide financial disclosure information. He may be reached at tel +32 53 21 68 39; email: dr.sallet@ooginstituut.be.

K. Robberecht, MD, FEBOphth, practices at Ooginstituut, Aalst, Belgium. Dr. Robberecht did not provide financial disclosure information. She may be reached at tel +32 53 21 68 39; e-mail: dr.robberecht@ooginstituut.be.

TAKE-HOME MESSAGE

  • Perceptions of surgery vary between patients.
  • Explain to the patient that not all side effects are predictable.
  • Be cautious of treatment options in patients with large pupils.

Nov 2010