Recorded at ASCRS, Dr Ben LaHood (Australia) chats with Professor Graham Barrett (Australia) who has made an extensive contribution to ophthalmology including Rayner’s RayOne EMV enhanced monofocal IOL.
Dr Ben LaHood (host)
Dr Ben LaHood, refractive cataract and laser vision correction surgeon from Australia, has gained international recognition for his extensive research on astigmatism management and biometry, which is regularly shared around the world. Additionally, Dr Ben LaHood is the host of two widely popular ophthalmology-themed podcasts.
Professor Graham Barrett (guest)
Professor Graham Barrett, is a consultant ophthalmic surgeon at Sir Charles Gairdner Hospital and a Clinical Professor in the University of Western Australia’s Centre for Ophthalmology and Visual Science.
Professor Barrett has a made an extensive and varied contribution to ophthalmology, both nationally and internationally. He is founder and immediate past President of the AUSCRS.
- The goal of RayOne EMV: Professor Barrett collaborated with Rayner on the RayOne EMV enhanced monofocal IOL with the aim of improving vision to reduce the dependency on glasses while maintaining excellent visual quality. Unlike diffractive multifocal or extended depth of focus IOLs that often compromise the quality of vision, RayOne EMV seeks to provide standard monofocal levels of dysphotopsia.
- The concept behind RayOne EMV: Professor Barrett’s objective was to extend the depth of focus and ensure optimal usage of light. Over a decade ago, after thorough exploration of optics, he introduced the concept of extended depth of focus and ‘monofocal plus’. He aimed to strike a desirable balance between focus range and the amount of positive spherical aberration on the IOL optic.
- Professor Barrett’s choice of positive spherical aberration (+SA) rather than negative spherical aberration (-SA):
Alignment with the natural visual system: Positive spherical aberration aligns with our natural visual system, as our receptors are adapted to it.
– Less affected by decentration: Positive spherical aberration is less sensitive to decentration than negative spherical aberration. Therefore, even if the IOL is not perfectly centered, visual quality is less likely to be compromised.
– Optimal visual quality: Combining negative defocus (myopia) with positive spherical aberration provides better vision than having either aberration alone. Negative spherical aberration works synergistically with hyperopia, but most patients prefer a slight amount of myopia. In cases of monovision, positive spherical aberration is more likely to provide synergy.
- Using RayOne EMV with monovision: Professor Barrett recommends treating the first eye with either no refractive correction (plano) or slight myopia. Accurate results rely on optimising the lens constant. The target for the second eye can vary depending on the surgeon’s preference, ranging from perfect distance vision to including reading and intermediate vision. Modest monovision can be achieved with compatible refractive corrections such as -0.75 D or -1.0 D.
- Managing astigmatism with RayOne EMV Toric: Professor Barrett anticipates that the RayOne EMV Toric lens will become his primary choice for managing patients with astigmatism due to the high level of patient satisfaction and absence of dysphotopsia. Both Professor Barrett and Dr LaHood agree that they will always choose a toric IOL for patients with significant astigmatism, without emphasising the distinction between a standard lens and its toric variation
Connect with Professor Graham Barrett on social:
Professor Graham Barrett | LinkedIn