EyeWorld India September 2018 Issue

Views from Asia-Paci c Michael LAWLESS, MD Clinical Associate Professor Vision Eye Institute, Sydney, Australia 4/270 Victoria Ave., Chatswood 2067, NSW, Australia Tel. no. +61-294249999 michael.lawless@visioneyeinstitute.com.au D rs. Chang and Lee are to be congratulated for a head-to-head study of two commonly used toric monofocal IOLs. The sticky nature of the AcrySof lens in conjunction with its more flexible haptics would seem to explain its superiority over the Tecnis toric lens in terms of rotational stability at Day 1. It is only modern technology, particularly intraoperative wavefront aberrometry and the Zeiss Callisto digital marking system, which allows us to tease out the accuracy of toric placement. If you ask patients, I think they would be surprised that there is only a nine out of 10 chance that the premium toric lens they have paid for will stay in the correct, surgeon-placed position. We still have a way to go to meet patient’s expectations. “ If you ask patients, I think they would be surprised that there is only a nine out of 10 chance that the premium toric lens they have paid for will stay in the correct, surgeon-placed position. ” - Michael Lawless, MD One thing that I have felt helpful is advice given by Dr. Oshika at ASCRS in 2017, whereby he uses his finger to press on the primary incision at the time he removes the irrigation aspiration handpiece. This is after the final positioning of the toric IOL. By doing so, the anterior chamber remains deep and the toric IOL remains in its correct position. With digital alignment, we get it into the right position and by the time we remove the instruments and hydrate the wound, it may be 2 o or 3 o off and we do not really want to go back inside the eye to do a final adjustment for a small error. However, if you consider that the average mean rotation is 2.72 o at best in this study, then an extra few degrees can contribute to less than ideal results and so a method for ensuring placement stability can contribute to getting the most from these lenses. Another anecdotal observation is that when toric lenses are placed at an oblique axis as opposed to the horizontal and vertical, they are more likely to rotate in the early postoperative period. The authors did not mention this in their paper and it would be interesting to see whether this was a contributing factor for postoperative rotation. As surgeons get better at tear film optimization and biometry, as formulae improve, and now as we move towards total keratometry to accurately take into account the posterior corneal surface, there will be more and more toric IOLs placed and anything we can do to improve the accuracy of the placement and the ability of that lens to remain in position is relevant. Editors’ note: Dr. Lawless declared no relevant financial interests. difficult, such as a small pupil, or if the patient is from out of town. “I think that a CTR reduces ro- tation, but we didn’t directly study or prove this,” Dr. Chang said. The Inoue et al. study also mentioned limiting patient activity in the immediate postop period as a possible way to prevent IOL rotation. “I routinely tell all patients immediately upon conclusion of their surgery to keep their eye relaxed and avoid squeezing as I remove the speculum and drape,” Dr. Lee said. “We use a powered reclining chair in our surgery center, and I tell patients not to make any effort to sit up after the surgery and let the chair do all the work. I also tell them to be extremely careful to avoid eye rub- bing, lifting, and straining and to move in ‘slow motion’ for the first 24 hours.” Dr. Chang also said he will tell patients to avoid exercise and limit walking immediately following their surgery. “I imagine that once the patient leaves the ASC and starts walking, that may be just enough activity to allow some toric IOLs to move,” Dr. Chang said, acknowl- edging that he has “no idea” if limiting activity during the imme- diate postop period actually helps prevent rotation. Dr. Chang said he and Dr. Lee have shared their findings with Johnson & Johnson Vision, which is evaluating haptic modifications that could improve rotational stability of the Tecnis toric IOL. He said when adjustable IOLs become available, they will be the best toric platform. “[The] lack of potential rotation following adjustment will be one of the reasons why,” Dr. Chang said. EWAP References 1. Ma JJ, et al. Simple method for accurate alignment in toric phakic and aphakic intraocular lens im- plantation. J Cataract Refract Surg. 2008;34:1631–6. 2. Lee BS, et al. Comparison of the rotational stability of two toric intraocular lenses in 1273 consec- utive eyes. Ophthalmol. 2018 Mar 12. Epub ahead of print. 3. Inoue Y, et al. Axis misalign- ment of toric intraocular lens: placement error and postop- erative rotation. Ophthalmol. 2017;124:1424–1425. Editors’ note: Dr. Chang has Finan- cial interests with Carl Zeiss Med- itec, Johnson & Johnson Vision, and RxSight (Aliso Viejo, California). Dr. Lee has no financial interests related to his comments. Contact information Chang: dceye@earthlink.net Lee: bryan@bryanlee.pro EWAP CATARACT/IOL 35 September 2018