EyeWorld India December 2021 Issue

EWAP DECEMBER 2021 3 EDITORIAL EyeWorld Asia-Pacific • December 2021 • Vol. 17 No. 4 Graham Barrett Chief Medical Editor EyeWorld Asia-Pacific Abhay Vasavada Deputy Regional Editor EyeWorld Asia-Pacific T his issue deals in all aspects of achieving the perfect visual and refractive outcome for your patient, with a particular focus on presbyopia correction. In today’s practice it is very important that patients get all the relevant information regarding IOL options, and that they get enough time and opportunity to understand and process the information. Depending on the resources available, surgeons may use simulators, videos, brochures, or multiple meetings with the surgeon or staff in the practice. Crucial to the success of modern refractive cataract surgery is the quality of the biometric data obtained and the IOL power calculation formulas that are used for IOL selection. There have been tremen- dous technological and formula upgrades over the last 2 decades. We now have myriad optical biometers, the latest being the swept- source OCT technology; most help in making patient workflow smoother, reduce human errors, and allow surgeons to choose from the most accurate modern formulas without having to go online and calculate powers manually. Surgeons also now have the choice of implanting a particular monofocal or toric IOL and then fine tuning the refraction based on the actual postoperative outcomes and the patient’s desired out- comes using the two upcoming adjustable IOL technologies—the light adjustable IOL and the femtosecond laser tweakable IOL. This could be a boon to patients where “refractive IOL choices” are limit- ed, as with prior corneal procedures or stable glaucoma. Globally, more patients are seeking solutions to the enigma of presbyopia. These range from eyedrops to scleral procedures to cor- neal refractive laser techniques, synthetic or cryopreserved corneal tissue allografts, monovision strategies and even refractive lens ex- change. However, a word of caution as the surgeon needs to perform a thorough risk assessment and advise the correct strategy. At the end of the day, the amount of time you spend with your patient preoperatively, trying to understand their needs and expecta- tions, and discussing the pros and cons of each available technology is what will help make more and more patients happy. As we complete 2 years of the COVID-19 pandemic, challenges continue to present themselves, particularly in eye banking and tis- sue procurement as well as safety. In general, there has been a steep decline in the numbers of eye donations. This makes availability of corneal tissue a huge issue and, whenever available, the question of whether or not the virus can be transmitted to potential recipients still looms large. Eye banks, however, have modified their protocols and practices, and we hope that things get better on this front with more widespread availability of tissue in every part of Asia-Pacific. T his issue, the different options for IOL selection and the increase in the number of presbyopic solutions are highlighted as our main topic. Of interest, the light adjust- able lens has been in genesis for several decades, but is some- what less compelling than when originally proposed due to the increase in accuracy of IOL pre- diction based on preoperative measurements. Even patients who have had previous refractive surgery can be predicted with greater accuracy than ever thought possible. Factors that have improved prediction accuracy are the refinement of methods of prediction both for spherical and astig - matic outcomes and biometer accuracy. The introduction of swept- source technology has allowed measurements of axial length even with dense cataracts that previously required immersion or contact ultrasound. The measurement of axial length is highly predictable and repeatable across a range of different biometers. Mean keratometry is also, to a lesser extent, reproducible, but the measured corneal astigmatism can vary quite significantly between different instruments and on different occasions. Unexpected refrac- tive outcomes are more likely to reflect errors in keratometry rather than effective lens position (ELP) prediction. Improving the health of the ocular surface and fast acquisition of corneal surface measure- ments may improve accuracy and minimize disturbance of the tear film; however, alternatives to Placido-based autokeratometry such as Scheimpflug devices and swept-source OCT have yet to show evidence of better outcome. The relative lack of accuracy of ker- atometry can be addressed by considering multiple measurements of corneal power and then deriving an integrated medium K as incorpo- rated in the Barrett calculator available on the APACRS website. In selecting a biometer for their practice, the availability of ad- vanced formulas and optimization of constants in a biometer are important criteria. Instruments that include both optical methods of axial length measurement as well as both Scheimpflug and Placido imaging devices are attractive and worthy of consideration. There is no single device perfect for every surgeon and the discussions in this edition should prove helpful to those surgeons contemplating purchase of a new device for their practice. The COVID pandemic has obstructed our usual opportunity for in-person meetings over the past 18 months but with improved vaccinations we are hoping for travel to meetings in person to begin again in the new year. In the meantime, publications such as Eye- World Asia-Pacific have played an important role in communication and education and will continue to do so in the future. Let me take this opportunity to wish all our readers a restful and enjoyable festive season. EWAP