EyeWorld India September 2019 Issue

EWAP SEPTEMBER 2019 13 FEATURE Ìi Ài Ã}wV>Ì Û>ÌÃ° In addition to working with almost any grade of cataract and improving accuracy, the device incorporates the latest IOL calculation formulas created by experts such as Warren Hill, MD, and Graham Barrett, MD. These formulas, Dr. Weinstock said, improve on existing vÀÕ>Ã] VÀ«À>Ì} >ÀÌwV> intelligence into the nomograms that drive intraocular lens power selection. Dr. Donaldson added that the IOLMaster 700 “provides an image of the macula that is a very helpful screening tool for macular pathology in preparation for cataract surgery.” Dr. Garg noted that the IOLMaster 700 can also be combined with the CALLISTO eye system (Carl Zeiss Meditec) to provide a reference image to guide toric IOL placement. Acknowledging these advances in biometry, Dr. Lee noted that “[t]he question is, which technology will do the best job of measuring the posterior cornea? And that is something that will require more research to determine.” Intraoperative advances Ultrasound energy is one intraoperative parameter that has been the target of improvement for a number of technologies. “I have enjoyed using both the femtosecond laser and the miLOOP device [Carl Zeiss Meditec] to help reduce the amount of ultrasound energy I use, particularly during dense cataract cases,” Dr. Donaldson said. “Both devices help pre-fragment the lens in preparation for «>ViÕÃwV>Ì°» Like the Zepto, the miLOOP consists of a nitinol ring but is inserted into the lens capsule to bisect and chop the cataract. “The miLOOP is useful for the very dense lens,” Dr. Garg agreed. “It allows for segmentation of very hard nuclei with relatively little effort.” In his experience, the miLOOP helps in cases in which even the femtosecond laser was not ÃÕvwViÌ Ì vÀ>}iÌ Ìi `iÃi nucleus. “Additionally, it allows for easy cortical removal as the process of deploying the miLOOP loosens cortex from the capsular bag,” he said. Dr. Lee noted that the miLOOP can stress the zonules, and he doesn’t use it for cataracts with weak zonules, which is often the case for the type of dense cataracts the miLOOP is used for. Intraoperative precision is an obvious target for improvement. Dr. Weinstock uses the NGENUITY 3D Visualization System (Alcon), recently combined with other technologies such as the ORA System (Alcon). “This allows vÀ > ÕVÀi ivwViÌ >` heads-up oriented procedure, which everyone in the room can participate in and add value to,” he said. Dr. Donaldson also uses both the ORA and the CALLISTO to help orient toric lenses. “The A s described in this article, incremental changes to different aspects of cataract surgery have all contributed to improvements in outcomes for patients. Over the recent years, adoption of such advances has truly raised the bar for my practice. Barrett Formulae Nailing the refractive outcomes for our patients has never been more important in this era of refractive cataract surgery and biometry is an essential component which has evolved tremendously in recent years. The Barrett Suite of IOL formulae caters for all refractive scenarios with the Barrett Universal II (sphere prediction), Barrett Toric Calculator (includes algorithm for posterior corneal astigmatism), Barrett True-K and True-K Toric (for post refractive surgery IOL prediction) and the Barrett Rx formula (for correction of refractive surprises). The Barrett formulae have been shown to be very accurate and with this in my >À>iÌ>ÀÕ] Ì }ÛiÃ i > Ì v Vw`iVi Ì `iÛiÀ iÝViiÌ outcomes for all my patients. Verion Image Guided System For my toric patients, this system (from Alcon) has been invaluable. The imaging module captures preoperative keratometry data which is fed into a planning module for IOL prediction using the standard spherical formulae as well as the Barrett Toric Calculator. Anatomical landmarks are also captured and such information is transferred to the guidance module (attached to the operating microscope) to provide an image overlay for incision placements, toric IOL alignment, and multifocal IOL centration. This system is also able to use postoperative refractive data and measurements for A-constant optimization, surgically induced astigmatism calculation and postoperative audit of refractive outcomes. /Ã ÃÞÃÌi>Ã ÃÌÀi>i` Þ VV½Ã ÜÀyÜ >` ÌiÀi >Ài now plans to incorporate a swept-source optical biometer which will `iwÌiÞ >i Ì Ìi V«iÌi «>V>}i° Search for the “perfect” IOL IOL technology continues to evolve and the last few years has seen extended depth of focus (EDOF) and trifocal IOLs as the front runners. My go-to presbyopic IOL has been the Panoptix (Alcon) which provides an excellent range of vision with minimal dysphotopsias. However, there are exciting times ahead with the concept of post surgery refractive adjustment being the most eagerly awaited. Ophthalmology is a very technologically dependent specialty and as ophthalmologists, we have to move in tandem with the >`Û>ViiÌÃ ÕÀ wi` >` iLÀ>Vi Ìi >ÌiÃÌ ÌiV}Þ À`iÀ to provide the best care for our patients. 'FKVQTUo PQVG &T .GG KU C EQPUWNVCPV HQT #NEQP Lee Mun Wai, MD Medical Director, Lee Eye Center 44-46 Persiaran Greenhill, Ipoh, Perak 30450 munwailee@gmail.com ASIA-PACIFIC PERSPECTIVES