PSEUDOEXFOLIATION

Good preparation, with the necessary tools at hand, is key to reducing the risk of complications during cataract surgery in patients with pseudoexfoliation, said Raimo Uusitalo MD, Finland. “It has been reported that pseudoexfoliation increases the complication rate following cataract surgery by three to tenfold. But it has also been reported that with proper care and management this increase in complications is much reduced,†Dr Uusitalo told the 16th ESCRS Winter Meeting. Pseudoexfoliation is an age-related disease characterised by the production of extracellular material from in the eye’s anterior segment, he noted. The prevalence of the condition varies from country to country and from region to region, from 0.5 per cent to nearly 40 per cent.

In Finland, the incidence of pseudoexfoliation among patients presenting for cataract surgery is about 25 per cent to 35 per cent, depending on the region, he added. The problems that pseudoexfoliation can bring to patients undergoing cataract surgery include a high postoperative spike in intraocular pressure, an unstable anterior chamber, weakened zonules, a disrupted endothelial function and macular oedema, Dr Uusitalo said. The most obvious clinical sign of pseudoexfoliation is the presence of pseudoexfoliative material on the anterior capsule and the iris margin. In addition, the iris often becomes translucent at its margins. The pseudoexfoliative material will be present in less plainly visible places. However, the amount of pseudoexfoliative material deposition is not in itself predictive of the amount of additional difficulty that a cataract procedure will involve, Dr Uusitalo said. The presence of capsular glaucoma, on the other hand, is an almost sure sign that the patient will be more prone to postoperative IOP spikes and cystoid macular oedema. Preoperative broad fluctuations of IOP in general can presage poor postoperative pressure control. Stabilising IOP as much as possible may reduce such complications, he said. Pseudoexfoliation affects the iris in a number of ways, he said. For instance, the iris bleeds more easily because of increased vascularisation, and the pseudoexfoliation material obstructs the mydriasis of the iris, making the dilatation of the pupil more difficult. Nonetheless, surgeons should take all measures necessary to achieve adequate pupil dilatation in order to allow for a fairly wide capsulorrhexis. Dr Uusitalo noted that his usual practice is to first enlarge the pupil as much as possible with maximal medical intervention, with preoperative application of topical phenylephrine and lidocaine. If pupil dilatation is still insufficient he then moves on to the injection of a cohesive OVD and then to iris retractors and lastly to the performance of a sphincterotomy. “I think it’s crucial to make the capsulorrhexis a bit larger than normal, 5.5 even to 6.0mm always making sure to keep the capsulorrhexis a bit smaller than the diameter of the IOL’s optic,†Dr Uusitalo added. Zonules that are already loose preoperatively are another source of trouble in eyes with pseudoexfoliation, he noted. Dr Uusitalo said that a weakened zonule makes an implanted IOL more prone to decentration, which usually occurs soon after surgery but can sometimes occur years later. He added that to avoid unnecessary risks he generally does not perform bilateral cataract surgery in patients with pseudoexfoliation.

Treatment decisions

The presence of pseudoexfoliation can have a bearing on many aspects of phacoemulsification procedure. He noted, for example, that he prefers to use a bimanual technique in such eyes because it seems to result in a more stable anterior chamber and less stress on intraocular structures. He added that in eyes with weak zonules he finds that lifting the nucleus up with an OVD and then performing the chopping can improve the safety of the procedure. Capsular tension rings and iris retractors can be useful in cases where the capsular complex has become too unstable, he said. “All in all, I think that pseudoexfoliation is like snow in winter. You get more of it up north, but if you see it and equip yourself accordingly, you do just fine,†he concluded.