Soft multifocal simultaneous image contact lenses: a review

Abstract

Soft multifocal simultaneous image contact lenses have boomed in recent years due to the growing number of presbyopic patients demanding visual solutions, allowing them to maintain their current standard of living. The concept of ‘simultaneous image’ is based on blur interpretation and/or blur tolerance of superimposed multiple images on the retina formed by various powers of a contact lens. This is the basis for a specific type of multifocal contact lens developed for the compensation of presbyopia. Manufacturers have released a great variety of soft simultaneous image lens designs to meet different patient needs but their fitting is still unsatisfactory in some cases. Some presbyopes discontinue wearing contact lenses due to some limitations in visual quality and comfort that can be overcome with an appropriate contact lens selection based on a comprehensive pre‐fitting evaluation. This paper aims to review the different types of soft multifocal contact lenses that are currently available for presbyopic correction and to define the steps and factors crucial for their fitting, such as pupil, aberrations, accommodation and centring. A discussion about useful tools to achieve a customised fitting leading to a successful outcome, such as the defocus curve, power profile and questionnaires, is performed.

The effect of ageing on the ocular surface parameters

“…From these epidemiological data and considering that the most prevalence condition related with ageing is presbyopia [16], there are many patients worldwide in which both presbyopia and DED co-exist. Currently, multifocal contact lenses (MCLs) [17,18] and multifocal intraocular lenses (IOLs) [19] are both well-established and an effective way to compensate the presbyopia, reducing spectacle dependency. The ocular surface changes related to ageing may adversely affect the optical quality of the eye and could have a detrimental effect on the success of these treatments.…”

“…For example, in the case of IOL implantation, optimal pre-surgical ocular conditions are required in order to avoid risks such as severe DED, inaccurate IOL power estimation [20] and ocular discomfort after IOL [21]. Despite the fact that most of the research studies conducted until now have demonstrated that MCLs provide good visual quality results [17,[22][23][24][25][26][27], the prescription rate [28,29]) is low. Although many factors could be behind this low adherence, it should be noted that the CLs materials are the same as monofocal CLs.…”

Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control

“…Figure 1 shows different examples of multifocal contact lens designs. ese design concepts work under two different principles [9,32,36]: (i) alternating image, in which a translating movement of the lens when looking downwards results in viewing through an area with a different refractive power; and (ii) simultaneous image, where the simultaneous projection of the images coming from multiple target distances are presented to the eye at the same time at different focal planes. en, in the simultaneous image, there must be a neural adaptation to select the sharp image depending on the visual target.…”

“…In this review article, we present an overview of the recent developments of bifocal and multifocal contact lens designs for the correction of presbyopia and myopia control, including the optical design of different platforms for bifocality and multifocality, computational simulations and performance assessment, and their connection with the visual performance, patient acceptance, and efficacy. For further information on the performance of earlier designs for presbyopia correction [1,9] and myopia control, including orthokeratology [10,11], the reader must consult the abundant existing literature including several systematic reviews and meta-analyses on the former topic [12][13][14][15][16].…”

Power profiles in multifocal contact lenses with variable multifocal zone

“…The nominal distance‐vision power and addition is the only information available regarding the optical power of MCLs. The power profile of MCLs has been demonstrated to report important information that could be used during the fitting process …”