EyeWorld Asia-Pacific December 2011 Issue

37 EW DEVICES December 2011 AT A GLANCE • First indication of a tricky case may be when capsular bag wrinkles or moves during capsulorhexis • Early placement of a CTR may cause unneeded stress on zonules • Alternatives/additions to CTR include iris and capsule retractors, capsule tension segment, and dispersive viscoelastic used as a “virtual ring” • Concerns about misalignment of lens considered before implantation of multifocal or toric lenses in PXF patients with weak zonules • Use of nonsteroidals may help combat CME in patients, while prostaglandin use may be continued attached to the limbus after an anterior capsulotomy like a retraction device or sutured to the sclera for long-term stabilization. Dr. Ahmed developed the Ahmed CTS (Morcher), which received US Food and Drug Administration approval in 2010. “It’s different from the other retractors in that it supports a wide area of the capsular equator, which is the most important part of the bag to support,” Dr. Ahmed said. Dr. Condon said that a dispersive viscoelastic can also be placed to act as a “virtual ring” in the same manner as hydrodissection. “If you inject it just under the capsulorhexis edge so that it goes out under the peripheral part of the capsular bag, it expands it like a CTR but doesn’t put any undue stress on the zonules while you’re injecting it,” he said. “This separates the lens material from the capsular bag and tensions the posterior capsule bag; it stabilizes the entire environment in an easily perceived way and allows for safer, more controlled removal of the residual nuclear material.” Advancements in technology and fluidics also allow for a very precise phacoemulsification procedure with minimal stress on the zonules from moving the lens or capsular bag. Dr. Condon suggested adjusting the phacoemulsification machine parameters so that the procedure is putting the least amount of stress on the zonules. “That’s very achievable, whether you use chopping techniques or divide-and- conquer techniques,” he said. “Some of the newer forms of phacoemulsification, particularly the torsional form, allow us to do very gentle phaco on the lens without putting stress on it.” Multifocal and torics: To implant or not to implant? There is some controversy about inserting multifocal or toric IOLs in PXF patients for fear that the unstable capsular bag may lead to misalignment of the lens. “Patients have to be aware that while these lenses can be viable in many cases of PXF, there’s always the concern that eventual subluxation, or malposition of the capsular bag and lens complex, can lead to ineffectiveness of what they had before, possibly making their vision worse,” Dr. Condon said. Dr. Ahmed said he regularly implants premium lenses in PXF patients with zonulopathy or phacodonesis. “I have no problem, as long as I’ve supported the bag sufficiently,” he said. “For example, in someone who has loose zonules, if I’m going to use a toric or multifocal, I would look at using a capsular tension segment and suturing the bag in place. If I didn’t do that, I’d be very concerned about a multifocal or toric lens because of concerns about misalignment.” Dr. Hart said he takes a more conservative approach. “If there is preoperative phacodonesis, I think that premium IOLs are contraindicated,” he said. Views from Asia-Pacific YAO Ke, MD Professor & Chief, Eye Center, Second Affiliated Hospital, School of Medicine, Zheijiang University 88 Jiefang Road, Hangzhou, China Tel. no. +86-571-87783897 Fax no. +86-571-877839087 xlren@zju.edu.cn I t is essential to discuss the usage of CTR for PXF patients with weak zonules. As we know, weak zonules are not an uncommon sign in clinical work. It might be caused by PXF, high myopia, trauma, and some other, rare diseases. In order to balance the stress in all directions and prevent the occurrence of a floppy capsular bag, CTR implantation is a nice choice in patients with weak zonules. It is quite effective to use the iris retractors to hook around the edges of the capsulorhexis in patients with a small range of lens subluxation. CTRs rarely cause damage to the capsular bag, and we haven’t found any case in which an injectable CTR (CROMA, ACPi-11, Austria) has injured the capsular bag in our eye center. The appropriate time of implantation is crucial. The CTR could be introduced before or after phacoemulsification, depending on the prediction for the difficulty of the phacoemulsification. I appreciate the opinions concerning the alternatives/additions to CTRs in this article. However, I still have some concerns. Above all, although some of the newer forms of phacoemulsification, including the torsional form, are acceptable, I prefer the iris-plane stop and chop technique that does less harm to the zonules and may be the best choice. Secondly, according to our experience, spectacles can effectively overcome the weakness of loss of accommodation. Therefore, it is not necessary to insert multifocal or toric IOLs in such complex cases. What’s more, anterior megalophthalmos should be included in the differential diagnosis of weak zonules in which the implantation of a CTR will expand the originally enlarged capsular bag, aggravating the IOL dislocation in the capsule bag. Editors’ note: Prof. Yao has no financial interests related to his comments. Prostaglandin usage Dr. Condon said he does not stop prostaglandin use in patients who are already taking the drug for glaucoma, especially those with moderate disease that may be somewhat precariously controlled. “I will supplement their pre- and postoperative management with a nonsteroidal anti- inflammatory agent, which is less likely to result in the prostaglandin having unwanted side effects such as cystoid macular edema,” Dr. Condon said. Dr. Ahmed agreed and said he doesn’t stop prostaglandin use either. “Nonsteroidals mitigate the risk of CME, and I like having the prostaglandins on board to deal with potential IOP spikes after cataract surgery,” he said. EW Editors’ note: Dr. Ahmed has financial interests with AMO. Dr. Condon has financial interests with Alcon (Fort Worth, Texas, USA/ Hünenberg, Switzerland). Dr. Hart has no financial interests related to his comments. Contact information Ahmed: 416-625 3937, ike.ahmed@utoronto.ca Condon: garrycondon@gmail.com Hart: 248-855-1020, j.c.hartjr@sbcglobal.net