Developments in the correction of presbyopia I: spectacle and contact lenses

Abstract

Purpose: To outline the refractive problems associated with presbyopia and to review the basis and relative merits of currently-available methods for their correction, with detailed consideration of spectacle and contact lens approaches. Contents: In the developed world, most of the present population will spend roughly half their lives as presbyopes. The well-known presbyopic changes with age in amplitude of accommodation and required near addition are briefly reviewed, together with the less widely acknowledged slow drifts that occur in distance refraction. The desirability of restoring to presbyopes clear vision for objects at any distance, ideally corresponding to vergences within the range of at least 0 to À5 D, in any viewing direction, is stressed. A general outline is given of possible corrective methods. Methods which satisfy the needs of a 50 year-old may not be suitable for the 80 year-old. Corrections may involve both fixed-and variablefocus lens systems, and surgical methods which modify the optics of the cornea, replace the crystalline lens with different fixed optics, or attempt to at least partially restore active accommodation. Some more recent methods of spectacle and contact lens correction are described in more detail. Particular attention is given to recent commercially-developed spectacles in which the corrective power can be varied actively by either mechanical (liquid-filled deformable lenses or Alvarez lenses) or electrical (liquid crystal lenses) means to allow objects at different distances to be seen clearly. Contact lens corrections show less progress and are still preferred only by a minority of older patients, most of whom are early presbyopes. Summary: The rising proportion of presbyopes in the population, covering an age span of around 40 years, represents both a problem for those concerned with giving their patients the best vision possible at both far and near viewing distances and a commercial opportunity. Traditional single-vision distance and near, bifocal, and progressive spectacle lens solutions, together with contact lens modalities for presbyopic correction, are being challenged by a variety of new approaches. It remains to be seen whether the latter will receive wide acceptance in practice.

The effect of ageing on the ocular surface parameters

“…MCLs demonstrated to be a good choice as they provide good visual quality [18,21,22] the desired independency from spectacles and, no less important, the aesthetic benefit (desirable mostly by women). Despite all the reported benefits, the prescription rate is still quite low.…”

“…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.…”

Update on Presbyopia-correcting Drops

“…Thus, it causes the diminishing of vision-targeted life quality and occupational performance of many people over 40. [1][2][3][4][5] The physiopathology of presbyopia is not clearly known. However, it has been demonstrated that various factors including the hardening of the lens, changes in the elasticity of the lens capsule, lens dimension, geometry of zonular attachments and ciliary muscle contraction may be responsible for the accommodative loss in presbyopia.…”

“…In the accommodated eye, the forward and inward movement of the ciliary muscle allows the tension fiber system to take up the tractional forces from the posterior ZF and releases the tension in the anterior ZF; both the thickness and refractive power of the lens increase. [3][4][5] There are some surgical modalities including refractive lens exchange, mono-vision laser-assisted in situ keratomileusis (LASIK), blended vision LASIK, multifocal or accommodating intraocular lens (IOL) implantations and corneal inlay implantation for the treatment of presbyopia.4-7 Nonsurgical treatments for presbyopia include the use of near-glasses and contact lenses.5 Nowadays, otorities are speculating about topical parasympathomimetic drop treatment for pharmacological control of presbyopia, which is a nonsurgical option for the vast majority of people with near vision spectacle dependence over 40 years old. …”

“…It occurs in almost everyone at around 40 years of age. [1][2][3][4][5] Presbyopia affects visual tasks at near distance such as book reading, handcrafts, stitching, cooking and surgical operation. Thus, it causes the diminishing of vision-targeted life quality and occupational performance of many people over 40.…”