REFRACTIVE 28 EWAP JUNE 2023 Contact information Schallhorn: jschallhorn@gmail.com Waring: georgewaringiv@gmail.com Image quality (IQ) is an “emerging area of interest” in the field of ophthalmology, said George Waring IV, MD, and it all starts with what the patient’s image quality is at the outset. “With the required specialized diagnostics and interpretation of these diagnostics to understand the sources of optical dysfunction, that’s part of thae excitement of this. Now we’re building a foundation in the peer-reviewed literature to support the clinical impact, the optical impact on potential sources of optical dysfunction,” he said. “We now have ways to bring this into the office more readily, and it’s slowly making its way into the normal conversation and helping us understand the best way to provide the best outcomes.” The construct of visual acuity in objective terms dates back to the mid-1800s with Snellen visual acuity, Dr. Waring explained, but lens and corneal refractive surgeons have learned there is more to vision than Snellen visual acuity. “The qualitative aspects of visual acuity are often as important as the quantitative aspects of visual acuity, and technologies are emerging where we’re now able to have more quantitative aspects of quality of vision with the use of advanced diagnostics,” he said. These include understanding the impact at the preop stage of static and dynamic factors The role of preoperative ‘IQ’ by Liz Hillman EyeWorld (US) Editorial Co-Director of the tear film, of corneal shape of both the anterior and posterior surfaces, the optical quality of the cornea, the static and dynamic functions of the lens including various forms of opacity, the role of vitreous and vitreous opacities, and the role of the posterior capsule. “To understand how we’re going to push the limits both in objective and subjective aspects of people’s visual acuity, we have to be able to understand what we need to address and screen preoperatively to customize and plan. This might involve work on the tear film, the cornea, the lens and potentially the vitreous in certain patient populations,” he said. In his practice, Dr. Waring said an in-depth, customized vision analysis is conducted based on what the patient is being referred in for, with a different workup for laser vision correction patients vs. middle aged to older patients who are on the dysfunctional lens spectrum and will be evaluated for a surgical lens-based solution. A LASIK referral, for example, will have more focus on the corneal aspects of the patient’s preoperative visual quality with high-resolution aberrometers, such as the iDESIGN system (Johnson & Johnson Vision), Dr. Waring said, in addition to high-resolution tomography to assess corneal curvature, shape, and optical quality. The tear film and tear performance are also assessed. Dr. Waring noted the paper published by Gouvea et al. in 2019 that demonstrated the role of the tear film on optical quality. 1 A patient who is deemed to be in the second stage of optical maturity with dysfunctional lens syndrome will get the same workup as above, but attention is also paid to internal light scatter and reduced contrast sensitivity, as well as the loss of accommodation. “We use Scheimpflug densitometry to assess the impact of lens density from the dysfunctional lens on optical quality, and now the Pentacam AXL Wave [Oculus] has a built-in aberrometer that separates internal from external aberrations and allows us to understand the impact of lens density from the dysfunctional lens on optical quality,” Dr. Waring said. “With ray tracing technology, we help validate the dysfunctional lens index with iTrace [Tracey Technologies], which helps separate the internal lens from the anterior cornea to understand internal optical dysfunction. This helps us determine the source and the opportunities for improvement. Use of advanced diagnostics helps us decide whether a patient may be best served with a lens-based procedure or a corneal-based procedure.” Finally, there is the assessment of image quality preoperatively for the cataract This article originally appeared in the April 2023 issue of EyeWorld. It has been slightly modified and appears here with permission from the ASCRS Ophthalmic Services Corp.
RkJQdWJsaXNoZXIy Njk2NTg0