Pseudophakic Sequential Bioptics
Bioptics is a surgical procedure that addresses refractive error by combining the use of corneal and lenticular surgical techniques.1 The procedure was originally developed for high and extreme refractive error with phakic IOL implantation, followed by programmed LASIK 1 month later. Presently, a surgeon may combine any of the following techniques simultaneously or sequentially: PRK, LASIK or wavefront-guided LASIK with implant technologies including phakic ACIOL, phakic PCIOL, toric PCIOL, multifocal IOL or monofocal IOL.
In 1996, the first bioptics procedure we performed was a combination of ICL implant (ie, a STAAR Surgical AG [Nidau, Switzerland] PCIOL) plus a corneal LASIK procedure. The first step was to perform the ICL implant, which was followed by LASIK 1 month later to correct the residual defect. We continued to perform the above procedure until 2005. The time frame between both procedures was usually 1 month. Due to anisometropia discomfort in some patients during the 30-day waiting period, however, we began to perform both procedures (ie, astigmatism correction with LASIK plus ICL implant) on the same surgical date. We coined this new technique simultaneous bioptics.
The advantages for simultaneous bioptics are
• one simultaneous surgical procedure,
• two simultaneous postoperative periods (ie, the patient experiences both procedures and the postop follow-ups as unique), and
• better initial visual acuity.
On the other hand, the disadvantages are
• a longer surgical procedure time,
• complicated calculations,
• more possibility of complications (because there are two procedures), and
• possible residual refractive defect.
Simultaneous bioptics demands to move the patient from the laser setting to the OR. Due to the large number of surgeries we are used to performing in a surgical session, moving the patient from one place to the other was our main obstacle.
Thereafter, we started with a procedure called sequential bioptics, which consists of laser treatment 12 hours prior to the ICL implant. Currently, this is our routine procedure for patients with moderate and high astigmatism. We extended this technique to perform cataract surgery in monofocal and multifocal cases. Therefore, sequential bioptics is a technique that may be used for phakic and aphakic IOL implantations.
Candidates for multifocal IOL implantation do not tolerate any astigmatic residual error, which is why we assign them to the sequential procedure. The same concept may be applied for monofocal IOL patients with moderate or high astigmatism (>1.50 D)
Pseudophakic sequential bioptics implies the total correction of the topographic astigmatism prior to phaco surgery. There are three modes to correct astigmatism: (1) negative, (2) positive and (3) mixed (ie, trying to maintain the same corneal radius curvature). Our preference is to correct it in a negative or mixed way. The third mode is advantageous because we do not need to change the original K for the IOL calculation. On the other hand, in the negative mode, IOL calculation is obtained using the probable K that is obtained after LASIK and provided by the laser software. Once the IOL calculation has been done, the procedure is performed as usual (ie, 2.8-mm corneal temporal incision).
Pseudophakic sequential bioptics has helped us to perform surgery in patients who would never before be candidates for multifocal IOL implant. Another method is to correct the astigmatism 1 month after phaco surgery. In patients with high astigmatism, however, the multifocal IOL may cause transitory bad vision quality during this month. This does not allow the patient to adapt properly to the implant.
We are highly satisfied with our results. Over approximately the past 18 months, we have performed 368 phakic (ICL plus LASIK) sequential bioptics procedures as well as 265 pseudophakic sequential bioptics — 210 of the procedures were done with Acrysof (Alcon Laboratories, Fort Worth, Texas) monofocal IOLs and 55 were done with Restor (Alcon Laboratories) multifocal IOLs.
The main restriction of this procedure is related to the IOL calculation. By using the possibilities described before, we manage to achieve an adequate precision. In cases with a small refractive residual error, we can proceed to correct it in a period of 1 to 2 months. To conclude, our goal is to give the patient as much immediate and maximum comfort as possible.
Roberto Zaldivar, MD, is the scientific director of the Instituto Zaldivar, in Mendoza, Argentina. Dr. Zaldivar states that he has no financial interest in the products or companies mentioned. He may be reached at zaldivar@zaldivar.com or +54 261 441 9999.
Juan C. Grandin, MD, is in the cornea department at the Instituto Zaldivar, in Mendoza, Argentina. Dr. Grandin states that he has no financial interest in the products or companies mentioned. He may be reached at jcgrandin@institutozaldivar.com or +54 261 441 9999.
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