![]() ![]() 7,15 An extended continuous focal point is different from two or three peaks of best visual acuity with bifocal or trifocal IOLs and helps reduce overlap of near and far images. Extended depth-of-focus (EDOF) IOLs, such as the Tecnis Symfony (Johnson & Johnson Vision), combine a unique diffractive pattern with technology that corrects corneal chromatic aberration, resulting in an elongated depth of focus and enhanced contrast sensitivity.11-13 PanOptix uses 88% of light energy (instead of 82% with older diffractive bifocals) and reduced dependence on pupil size. The newest trifocal, PanOptix (Alcon), also employs a diffractive design, but improves on it to provide better unaided intermediate vision. ![]() 10Įxamples of diffractive bifocal IOLs include Restor (Alcon) and Tecnis multifocal IOL (Johnson & Johnson Vision). This affects contrast and exacerbates haloes and glare. 10īoth refractive and diffractive designs cause an in-focus image to be overlaid by at least one out-of-focus image. 9 About 41% of incident light is allocated to distance focus, 41% to near and 18% is directed to higher-order diffraction, rendering it unusable. 8 This design does not completely eliminate stray light. This helps reduce glare and higher-order aberrations. Diffractive multifocals possess concentric diffractive surfaces on the posterior portion, inducing wavefront interference.7-8 Early examples of this design include the Array and ReZoom (both originally from AMO, now Johnson & Johnson Vision). As pupils decrease in size with the near reflex, the effective power of the lens is increased. These are highly dependent on the patient’s pupil size, as the changes in pupil diameter affect the number of zones in use. Refractive multifocals use concentric zones of increasing dioptric power on the anterior lens surface with highest power in the center of the lens.6 Today’s multifocals function according to one of three different optic principles: refractive, diffractive or extended-depth-of focus. Different brands use different technologies to achieve this. 5Īll multifocal IOLs work by separating light into different foci, causing a dispersion of light energy. Many patients have benefited greatly from multifocals, but some are extremely dissatisfied with either these unwanted visual phenomena, quality of vision, or higher-than-expected dependency on corrective lenses. However, the multifocal lens design can result in a higher incidence of unwanted visual phenomena such as contrast sensitivity loss, glare and halos. Since 1997, multifocal IOLs have provided similarly good distance vision as monofocals, but they surpass their predecessor when it comes to intermediate and near vision. IOL technology is ever-evolving, with new products entering the market on a regular basis. So, the first step to managing cataract patients is to bone up on what’s available. It stands to reason that the doctor must have a comprehensive understanding of the technologies and techniques associated with a procedure before they can educate or even evaluate their patient for it. PanOptix IOL (Alcon), the newest diffractive trifocal IOL, provides good unaided visual acuity at distance, intermediate and near. When careful patient selection and counseling are combined with good surgical skill and knowledgeable postoperative management, most patients should be able to achieve those boast-worthy outcomes that continue driving patients to keep their eyes in top shape. While we don’t always see these top-notch outcomes, we are fortunate enough to live in an age when many of those demands can be met.Īs optometrists take a larger role in postoperative care of cataract patients, it is imperative to stay up-to-date on intraocular lens (IOL) advancements, counseling techniques, pharmaceutical management of the post-op course and more. This demand is, in part, fueled by the success stories patients hear from their friends or family members scrapping glasses and having “perfect vision” at all distances. For many, good uncorrected distance vision is not enough anymore, and complete spectacle independence is the goal. These days, patients undergoing cataract surgery live more active lifestyles, spending large amounts of time both outdoors and in front of computers or smartphones. ![]() Modern cataract surgery is perceived as refractive surgery, and expectations are high. ![]()
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