Developments in the correction of presbyopia II: surgical approaches

Abstract

Purpose: To discuss the various static and dynamic surgical approaches which attempt to give presbyopes good vision at far, intermediate and near viewing distances. Content: Static methods broadly adopt the same optical techniques as those used in presbyopic contact lens correction and aim to satisfy the needs of the presbyope by increasing binocular depth-of-focus, often using monovision as well as simultaneous-imagery. Dynamic methods generally attempt to make use of at least some of the still-active elements of the accommodation system. They include procedures which are supposed to modify the relative geometry of the ciliary muscle and lens, or which reduce the stiffness of the presbyopic lens either by replacing it with other natural or man-made material or by subjecting it to femtosecond laser treatment. Alternatively the natural lens may be replaced by some form of intraocular lens which changes power as a result of forces derived from the still-active ciliary muscle, zonule and capsule, or other sources. Conclusions: At present, multifocal intraocular lenses appear to offer the most consistent and reliable surgical approach to surgical presbyopic correction. They have obvious advantages in convenience and stability over optically-similar, simultaneous-image presbyopic contact lenses but this must be balanced against their relative inflexibility in cases of patient dissatisfaction. Dynamic methods remain largely experimental. Although some approaches show promise, as yet no method has demonstrated a reliable, long-term ability to correct distance refractive error and to appropriately change ocular power in response to changes in viewing distance over the normal range of interest.

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.…”

Investigation on the intracorneal lens material biocompatibility using the model of the corneal stromal cell culture

“…Имплантация интракорнеальных линз (ИКЛ) является динамич но развивающимся направлением в хирургической коррекции пресбиопии [3]. ИКЛ -это устройства, выполненные из синтетического полимера, име ющие дисковидную форму, диаметр 1,5-2,0 мм и имплантируемые в центральную зону стромы ро говицы с целью изменения ее оптической силы.…”

“…Качественную оценку биологической совмести мости исследуемых материалов формировали по форме кривых клеточного роста на основании из вестных критериев биосовместимости [3].…”

KAMRA corneal inlay for the correction of presbyopia

“…Some of them are: multifocal intraocular lenses [1], monovision with intraocular lenses or LASIK [2], and implantation of presbyopia-correcting intraocular lenses [3], but none of them is without disadvantages, which usually lead to patient dissatisfaction.…”