FEATURE EWAP MARCH 2022 17 splitting, we don’t have to be as concerned about ocular pathology,” he said, describing it as a great lens for patients who wanted a multifocal. He still considers significant ocular pathology a contra-indication for Vivity in his practice. As Dr. Donnenfeld put it, the more near vision a presbyopiacorrecting IOL provides, the more dysphotopsias can be expected. He said clinical trials showed that dysphotopsias were reduced with lower add multifocal IOLs. Lower add EDOF lenses also showed improvements in dysphotopsias. Further, Vivity and Eyhance (Johnson & Johnson Vision), he said, provide 0.75 D–0.5 D of near vision, but he’s seen dysphotopsias associated with these lenses similar to that of monofocal IOLs. “These two presbyopiacorrecting IOLs are refractive rather than diffractive and have become my IOLs of choice for patients who traditionally I would not consider candidates for a [presbyopia-correcting] solution,” Dr. Donnenfeld said. “I have placed them in post- LASIK, epiretinal membrane, and mild glaucomatous eyes with good success. The important conversation to have with these patients is the correct expectation of how much near vision they will receive, and I often will offer these patients mini-monovision of 0.50–1.0 D in their non-dominant eye, which provides them with an effective 1.0–1.75 D of near.” In general, Dr. Donnenfeld said presbyopia-correcting IOL technologies over time have smoothed transition zones for decreased dysphotopsias in all patients, but especially in those less than perfect eyes. “Any IOL that splits light is going to increase dysphotopsias. The next major breakthrough in presbyopia-correcting IOLs will be true accommodating IOLs. These lenses will be ideal for less than perfect eyes. For patients with corneal irregularities, the pinhole IOLs will improve dysphotopsias in less than perfect eyes.” Dr. Donnenfeld said he’s found post-LASIK patients to be among the most interested in presbyopia-correcting solutions. However, some patients in this population can fit in the category of “imperfect eyes.” “Eyes with low hyperopia or myopia corrections with modern ablation profiles and centered ablations do well with all the presbyopia-correcting options,” Dr. Donnenfeld said. “Patients with older ablation profiles that were more oblate, decentered ablation, or higher refractive W hile modern diffractive trifocal IOLs perform well when emmetropia is achieved in healthy eyes, providing spectacle independence around 90% of the time, careful screening of the eye and patient are crucial because of the compromise on the quality of vision. Based on a light-splitting optical principle, only part of the incident light is in focus at any time, causing reduced contrast sensitivity. The remaining defocused light is lost to halo and glare formation. Thus, imperfect eyes and patients intolerant to halos and glare and those with unrealistic expectations are unsuitable candidates for multifocal IOLs. Today, there are new IOLs we can use when faced with mildly compromised eyes or fussy patients desiring spectacle independence. I offer monovision with enhanced monofocal IOLs (Eyhance) or EDOF IOLs (Vivity) which do not split light. Both IOLs thus provide the visual µuality and dysphotopsia profile of a monofocal I"L. As the central refractive element is minimally raised, these IOLs are tolerant to decentration when there is mild âonulysis. Because of the flat landing seen in the defocus curve, they are tolerant to refractive inaccuracies encountered in post LASIK eyes and hypermature cataracts where optical biometry is not possible. Based on continuous higher-order aspheric surface with the power, the Eyhance provides an effective add power of ~0.5 to 0.75 D. When used in monovision with the non-dominant eye targeting –1.50 to –1.75 D, the IOL increases spectacle independence, enabling the patient to read unaided. If binocular distance vision is important, I offer Vivity, which is based on a wavefront-shaping optical principle, resulting in an extended focus. With an effective add power of ~1.5D, it provides continuous vision from distance up to 66 cm, and functional near vision. To improve spectacle independence, micro-monovision of –0.5 to –0.75 D may be practiced. I have successfully used this lens in eyes with mild imperfections: epiretinal membrane, dry age-related macular degeneration, glaucomatous visual field defects, âonular dehiscence, irregular astigmatism, ocular surface disease and post myopic cornea refractive status. In addition, this IOL in the imperfect eye can be matched with a diffractive trifocal IOL in the fellow healthy eye. This IOL is also compatible with a previously implanted monofocal IOL to provide intermediate vision without sacrificing distance vision. Finally, it is important to explain the limitation of these IOLs to patients, and my comments are specific to the named I"Ls and may not apply to other IOLs with added depth. ditors½ note\ Dr. hee declared no relevant financial interest. Chee Soon Phaik, MD Senior Consultant, Singapore National Eye Centre 11 Third Hospital Avenue, Singapore 168751 chee.soon.phaik@singhealth.com.sg ASIA-PACIFIC PERSPECTIVES
RkJQdWJsaXNoZXIy Njk2NTg0