EWAP MARCH 2023 3 EDITORIAL EyeWorld Asia-Pacific • March 2023 • Vol. 19 No. 1 One of the most interesting trends covered in the issue is the increase in interest in modest monovision, in part related to a great opportunity for blended vision when it is used within the context of new extended depth of focus (EDOF) IOLs. I have used monovision for decades and have extolled the virtues of this approach as an alternative to multifocal IOLs. It is important to preserve binocular acuity and reduce asthenopia by limiting the targeted level of myopia in the near eye. An ideal target for modest monovision is –1.25 D as stereoacuity is well preserved and there is less chance of reduced binocular contract sensitivity and asthenopia. However, while this level of targeted myopia will provide excellent intermediate acuity, total spectacle dependence is expected in approximately 30% of patients. And yet despite this limitation, patient satisfaction is extremely high; total spectacle independence in the context of multifocals may not have been the best parameter to address the success of a presbyopic solution from a patients’ perspective. The advent of EDOF IOLs offers a great new opportunity to utilize modest monovision as the extended depth of focus allows overlap of the distance in the near eye resulting in true blended vision and a continuous range of focus without the dysphotopsia typically encountered with trifocal IOLs, particularly those based on a refractive principle. EDOF IOLs can of course be used without monovision and still provide excellent intermediate acuity, but the synergy of utilizing myopic defocus in one eye greatly improves the potential for spectacle independence. A range of myopic defocus can be utilized with a target as low as –0.50 D extending up to –1.50 D, although a target of approximately –1.0 D is considered ideal in this context. The extended depth of focus will better preserve distance vision with the same level of myopia as well as additional reading ability. My personal experience is primarily combining modest monovision with the Rayner EMV lens, which from the outset conceived that the principle of aspherical aberration was ideally suited to combination with a modest level of myopia; the clinical results detailed by Yeo Tun Kuan in this issue confirm the utility of this approach. Modest monovision can of course be utilized with other EDOF IOLs but the impact of myopic defocus will vary depending on the ocular principle as the EDOF group is not homogeneous but includes lenses based on different optical principles. Myopic defocus may impact the contrast as well as the likelihood of dysphotopsia with some other EDOF IOLs. I hope the increasing availability of EDOF IOLs will encourage surgeons to consider the use of this powerful optical mechanism to address presbyopia and experience the magic of modest monovision. Graham Barrett Chief Medical Editor EyeWorld Asia-Pacific • China • Korea • India
RkJQdWJsaXNoZXIy Njk2NTg0