*3.2.1.2.2 Non-apodized diffractive IOLs*

In contrast to the apodized IOLs, the diffractive steps of non-apοdized diffractive IOLs have uniform height from the center to the periphery. Therefore, these IOLs can distribute the light rays to near and distant focal points in constant proportions, irrespectively of the pupillary size [61, 68]. However, they sacrifice some intermediate vision, and may produce more photic phenomena than apodized diffractive IOLs [62].

Some characteristic non-apodized diffractive IOL models are the following:


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*Pseudophakic Presbyopic Corrections*

*DOI: http://dx.doi.org/10.5772/intechopen.96528*

and determination of patient's expectations.

*3.2.2.2 Patient factors/preoperative counseling*

the following aspects should be discussed:

disturbance by glare and halos [74].

occupation, and expectations should not be omitted.

*3.2.2.1 Clinical factors/exclusion criteria, contraindications*

*3.2.2 Preoperative counseling, preoperative examination and patient selection*

Preoperative counseling and patient selection play a pivotal role in the success of pseudophakic presbyopic correction with implantation of mIOLs. It is well known that patients wishing to undergo presbyopic correction have high expectations for their visual and refractive outcome. Thus, it is common that some patients with a visual acuity of 0.0 logMAR are not fully satisfied usually due to photic phenomena at scotopic or mesopic light conditions (e.g. during nighttime driving) and difficulty in reading of very small letters or small letters under lower lighting levels. Some possible reasons of dissatisfaction are potential optical aberrations, residual astigmatism, large pupil and slow or no neuroadaptation [13]. For this reason, a good counseling and a thorough preoperative examination should be an integral part of the preoperative patient management for the best possible patient selection

Before the discussion between patient and surgeon for an eventual pseudophakic

presbyopic correction with implantation of a mIOL, a detailed patient history should be taken and a first general ophthalmologic examination (VA, slit-lamp biomicroscopy, IOP measurement) should be performed, which might reveal some clinical parameters that could rule out this type of surgery; among them, significant preexisting ocular pathology that could reduce the postoperative visual outcome, severe untreated dry eye disease, Fuch's endothelial dystrophy or other corneal dystrophies, keratoconus, corneal scars, macular degeneration, diabetic retinopathy or other retinal disease, advanced glaucoma or other optic nerve diseases, and amblyopia. In addition, mIOLs should be avoided in patients with pupillary abnormalities such as corectopia and colobomas, as well as in patients with phacodonesis zonular dialysis or pseudoexfoliation due to the high risk of IOL decentration [61, 64].

The history taking and the general ophthalmologic examination should be followed by a detailed preoperative counseling. As part of the counseling, each patient should be warned about the risks of the lens extraction surgery, but also for the specific risks of the implantation of a mIOL. The selection of both the proper patient and the proper mIOL results in high patient satisfaction rates. Specifically,

The determination of each patient's personality type, lifestyle, hobbies, needs,

• *Personality:* Surgeons should be cautious about selecting patients with a type A personality. Specifically, patients with neurotic personality traits are less likely to be satisfied with the postoperative outcome in comparison with patients whose dominant personality trait is conscientiousness and agreeableness [73]. Additionally, the personality characteristics of compulsive checking, orderliness, competence, and dutifulness have found to be related to subjective

• *Lifestyle, hobbies, needs:* Patients who read a lot may benefit more from a mIOL that provides better near vision, while patients who use a computer may benefit more from a mIOL that provides better intermediate vision. Trifocal IOLs would be a good solution for patients that need both near and intermediate

*Current Cataract Surgical Techniques*

*3.2.1.2.2 Non-apodized diffractive IOLs*

diffractive IOLs [62].

**Figure 4.**

*focal point.*

add power) [70].

plane), biconvex IOL [71].

In contrast to the apodized IOLs, the diffractive steps of non-apοdized diffractive IOLs have uniform height from the center to the periphery. Therefore, these IOLs can distribute the light rays to near and distant focal points in constant proportions, irrespectively of the pupillary size [61, 68]. However, they sacrifice some intermediate vision, and may produce more photic phenomena than apodized

*Light distribution in photopic (A) and mesopic-scotopic (B) light conditions in diffractive apodized IOL designs. (A) The small pupil diameter in photopic conditions, when both distance and near vision are utilized, allows light energy to be directed equally to distance and near. (B) The wide pupil diameter in low light conditions, when only the distance vision is utilized, allows more energy to be directed to the distance* 

Some characteristic non-apodized diffractive IOL models are the following:

• TECNIS multifocal IOL (AMO, Santa Ana, CA): a single-piece diffractive, non-apodized, aspheric (aspheric anterior surface, full-diffractive posterior surface), bifocal IOL (ZMB00: +4.00 D / ZLB00: +3.25 D / ZKB00: +2.75 D

• AT LISA 809 IOL (Carl Zeiss Meditec AG, Jena, Germany): a single-piece

• AT LISA TRI 839MP (IOL (Carl Zeiss Meditec AG, Jena, Germany): a singlepiece diffractive, non-apodized, aspheric trifocal IOL (+1.66 D intermediate

and +3.33 D near add power at the IOL plane) [72].

diffractive, non-apodized, aspheric bifocal (+3.75 D near add power at the IOL

single-piece diffractive, non-apodized, aspheric (spherical posterior surface and aspheric anterior surface with a diffractive surface on the central 4.5 mm), trifocal IOL (+2.17 D intermediate and +3.25 D near add power at the IOL plane) [69].

• AcrySof IQ PanOptix (Alcon Laboratories, Inc., Fort Worth, TX, USA): a

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