Eyeworld

EW INTERNATIONAL 68 August 2018 by Maxine Lipner EyeWorld Senior Contributing Writer the cases," he said. "This is one of the first studies where there was a real mix of surgeons of all levels in the hospital." Included here were 10 consultants and 10 specialists of var- ious grades of training with regard to implanting these lenses. Toric investigations Included were 32 eyes of 24 patients who underwent cataract surgery during a 10-month period. Inves- tigators found that approximately 81% of patients obtained an im- provement in best corrected visual acuity after surgery with a toric lens implant, which they may not have achieved with a standard lens implant given their astigmatism. "Also, 80% of eyes ended up within plus or minus 1 D of the predicted refractive outcome, which is quite reasonable," Dr. Xue said. He thinks this suggests that the majority of patients experienced a real benefit from the toric implant. However, not all cases went smoothly. Three patients required further surgery to rectify a lens rotation. "Two of those patients had previous retinal detachment repair or vitrectomy, which seems to be a How these perform in everyday practice T oric lenses have become an important part of the cataract surgeon's tool box. But how effective are these lenses in the real world? In a study published in BMC Ophthal- mology, investigators took a look at this. Investigators found that while the majority did well, 9% of eyes re- quired further intervention to rectify IOL rotation, according to Kanmin Xue, MB, PhD, clinical lecturer, University of Oxford, U.K. In the unit in which Dr. Xue works, toric lenses are commonly placed in the eyes of patients who have corneal astigmatism of greater than 2.5 D. Investigators wanted to see if it was clinically useful and cost effective to do so, Dr. Xue explained. He felt that his unit was in a prime position to examine this. "There isn't a lot of data in the general health service setting on toric lenses because a lot of published results come from specialists who are ex- perts at putting in toric lenses, and usually it's one surgeon doing all of risk factor for lens rotation," Dr. Xue said. One possibility is that there is less gel pushing on the lens, which means that there's more freedom for the lens to rotate. Or there is zonular weakness that allows for the rotation. "In those patients I would be particularly careful in counsel- ing them about the potential risks before implanting a toric lens," Dr. Xue said. "Also, it's relevant when you are trying to do a public health- care type of cost analysis." For this you have to take into account the potential need for a second surgery, with the associated cost. It's important to know which candidates may be at risk for lens rotation, such as those who are post-vitrectomy. Dr. Xue said this doesn't mean they can't have a toric lens, only that they need to be aware of the heightened risk of rota- tion, which may need to be rectified with a second procedure. Still, the majority of patients with significant astigmatism benefited from a toric lens, and rotations are relatively rare. "The spectacle freedom is an important point here," he noted, adding that patients are happy to be able to get out of their glasses. "Overall, the data is positive. Most patients do benefit from toric lenses, and rotations are rare in nor- mal individuals with no other past ocular history," he said. Practical strategies There are some practical strategies that practitioners can use to mini- mize the risk of lens rotation. Rather than polishing the capsule, practi- tioners could leave some residual cells on the anterior lens capsule, which helps to provide a bit more "friction" to stabilize the IOL, Dr. Xue explained. Or practitioners may try slightly under-rotating the lens just before removing the OVD at the end. "When you remove the OVD, the lens tends to wobble slightly and rotate clockwise," he said. Dr. Xue hopes practitioners come away from the study with the realization that 80% of patients benefit from toric lens implantation with visual acuity improvement in their treated eye, which is compa- rable to that attained with standard cataract surgery. "The other take- home message is that the lens rota- tion risk is there, particularly if the patient has had a previous vitrecto- my," he said. Dr. Xue continues to implant toric lenses in his unit. "We're happy that we have that option available for our patients," he said. "Cataract surgery with toric lens implantation helps to achieve spec- tacle-free vision, which improves patient satisfaction, and is relatively straightforward to perform. We hope to continue to offer this and work on ways to pick out patients who are at high risk of lens rotation in order to counsel them appropriately and modify our surgical technique to minimize the risks." EW Reference 1. Xue K, et al. Real-world refractive outcomes of toric intraocular lens implantation in a Unit- ed Kingdom National Health Service setting. BMC Ophthalmol. 2018;18:30. Editors' note: Dr. Xue has no financial interests related to his comments. Contact information Xue: enquiries@eye.ox.ac.uk Real-world spin on toric lenses In eyes like this with a toric implant, the majority of patients do well, but in a few cases realignment may be needed. Source: Kanmin Xue, MB, PhD Research highlight " Most patients do benefit from toric lenses, and rotations are rare in normal individuals with no other past ocular history. " —Kanmin Xue, MB, PhD

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