EyeWorld India June 2023 Issue

CATARACT 24 EWAP JUNE 2023 Dr. Riaz said that multivariable formulas consistently outperform third-generation IOL formulas, perhaps because these formulas use biometric variables beyond just AL/K. “I don’t think we have enough data to definitively advise that ‘formula X’ should be used with ‘IOL Y’ yet; that certainly is a topic for future research. I think that biometry technology makes a difference as well. Our group is actively exploring this idea that there are ideal combinations for formula plus IOL platform with optimized lens constants plus biometry device that remain to be identified,” he said. “It is important to stress that I do not mean to imply superiority/ inferiority of a given IOL platform. However, I think the ideal triumvirate is to identify in the future that ‘formula X’ should be used with ‘IOL Y’ if you are using ‘biometry device Z.’” Dr. Tsai said that she compares multiple formulas in order to achieve the best outcomes with advanced- technology IOLs. “Some IOL formulas have been shown to be more accurate in certain situations like extreme axial length, post-refractive state, etc.,” she said. “I pay special attention to newer fourth-generation power calculation formulas like Barrett, Hill-RBF, and Olsen, particularly in longer and shorter axial lengths. Personalizing my IOL constants has always worked for me in the past but can be time consuming. “If a toric platform is needed for any IOL, it is important to select a calculator that includes posterior corneal astigmatism (PCA) and surgically induced astigmatism (SIA) contributions. These are often found on the company’s website or with the Barrett Toric Calculator,” Dr. Tsai continued. Dr. Tsai said that because she uses the IOLMaster 700, she will review third-generation formulas, but she pays special attention to fourth-generation formulas that are included with the machine’s IOL calculator, especially the Barrett formula. “For patients who have a history of refractive surgery, I will review the Barrett True-K with TK and Haigis-L with TK, which are also included on the IOLMaster 700,” Dr. Tsai said. “Then I will compare the results with the ASCRS IOL Calculator, which has shown to be the most accurate for these patients. Occasionally, I will use the ORA System [Alcon] in patients where I think additional information is preferred to obtain the highest accuracy in my results.” Like Dr. Riaz, Dr. Tsai said she has also recently started using the ESCRS IOL Calculator, which gives the results of the Barrett, Cooke K6, EVO, Hill-RBF, Hoffer QST, Kane, and PEARL-DGS formulas. Once the IOL is implanted, all the physicians said there is a patient adaptation period. Dr. Wang said, “postop adaptation is a variable process that may depend both on the patient and the IOL design.” She said it usually takes between 3–6 months. Dr. Tsai said she gives patients at least 3 months to adapt to the IOL technology, but she often encourages them to try up to a year if they’re willing. Patients might need to adapt to color changes and positive and negative dysphotopsias. She said that most patients will adapt to these visual phenomena, especially if their cataract was causing visual dissatisfaction preop. “If they have no improvement of symptoms by 3 months and are extremely bothered by visual quality, I would start the conversation regarding a possible IOL exchange. Luckily, I have not found that I’ve had to exchange many implants due to multifocal quality complaints,” Dr. Tsai said. Dr. Riaz said that he also asks patients to take between 3–6 months to neuroadapt. With diffractive optics, Dr. Riaz said he considers objective measures (angle alpha being more than angle kappa) and subjective (assessment of personality types). In general, Dr. Riaz said he doesn’t recommend IOLs with diffractive optics to patients with angle alphas more than 0.4 mm. He said personality is an even larger factor in his practice. “There are far too many practices where the surgeon only meets the patient on the day of surgery, and the IOL choice has been made by an optometrist or ancillary staff. The unhappy patients that present to clinicians are often burned by these experiences,” he said. “Assessment of patient personality (type A, engineer, high demands for near vision, etc.) and expectations are crucial and vary from patient to patient. This preop assessment is even more important than the surgery itself. The successful ‘neuroadaptation’ that happens postop begins with proper patient selection preop.” Beyond that, Dr. Riaz said that even with proper preoperative assessment, there will be a good number of patients who need handholding, reassurance, and observation of symptoms like glare, halos, and vision that’s not meeting their expectations postop. If patients are still unhappy at 3 months and they have not had a YAG capsulotomy, he will perform an exchange for a monofocal or Eyhance IOL (Johnson & Johnson Vision). Dr. Riaz said if the postop refraction is consistently myopic or hyperopic, residual refractive error could be to blame. Dr. Tsai

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