Accommodating Intraocular Lenses: Theory and Practice

Comander, Jason; Pineda, Roberto

doi:10.1097/iio.0b013e3181c552c9

Cited by 7 publications

(6 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The accommodative ability of passive-shift AIOLs is limited, with reported anterior movements insufficient to provide functionally significant amplitudes of accommodation. 6,59,76,91,133 Even if the designs of such implants could be modified to enable the magnitude of forward movement to be increased, it is likely that the levels of anterior shift needed to provide accommodative amplitudes facilitating spectacle independence (for example, 2.0 mm) would interfere with anterior segment geometry, causing problems that include iris bulging and pigment dispersion. 5,47 Despite the limited accommodative effects, passive-shift implants are used clinically around the world.…”

Section: Discussionmentioning

confidence: 99%

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

Sheppard

Bashir

Wolffsohn

et al. 2010

Clinical and Experimental Optometry

View full text Add to dashboard Cite

The correction of presbyopia and restoration of true accommodative function to the ageing eye is the focus of much ongoing research and clinical work. A range of accommodating intraocular lenses (AIOLs) implanted during cataract surgery has been developed and they are designed to change either their position or shape in response to ciliary muscle contraction to generate an increase in dioptric power. Two main design concepts exist. First, axial shift concepts rely on anterior axial movement of one or two optics creating accommodative ability. Second, curvature change designs are designed to provide significant amplitudes of accommodation with little physical displacement. Single-optic devices have been used most widely, although the true accommodative ability provided by forward shift of the optic appears limited and recent findings indicate that alternative factors such as flexing of the optic to alter ocular aberrations may be responsible for the enhanced near vision reported in published studies. Techniques for analysing the performance of AIOLs have not been standardised and clinical studies have reported findings using a wide range of both subjective and objective methods, making it difficult to gauge the success of these implants. There is a need for longitudinal studies using objective methods to assess long-term performance of AIOLs and to determine if true accommodation is restored by the designs available. While dual-optic and curvature change IOLs are designed to provide greater amplitudes of accommodation than is possible with single-optic devices, several of these implants are in the early stages of development and require significant further work before human use is possible. A number of challenges remain and must be addressed before the ultimate goal of restoring youthful levels of accommodation to the presbyopic eye can be achieved.

show abstract

Section: Discussionmentioning

confidence: 99%

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

Sheppard

Bashir

Wolffsohn

et al. 2010

Clinical and Experimental Optometry

View full text Add to dashboard Cite

show abstract

Section: ' Pseudoaccommodation Versus Accommodationmentioning

confidence: 99%

“…2 Pseudoaccommodation is the situation where patients have near vision in the absence of accommodation. 2 Examples include a small pupil increasing the depth of field, corneal astigmatism resulting in multifocality, and residual myopia. Some pseudophakic patients with In accommodative IOLs, a change of tension in the ciliary muscle results in a shift in the focal length of the IOL-eye optical system.…”

Section: ' Pseudoaccommodation Versus Accommodationmentioning

confidence: 99%

“…2 The original presumed mechanism was forward axial movement of the optic caused by contraction of the ciliary muscle. 7 Other mechanisms relate to changes in lens architecture with accommodative effort.…”

Section: Single-optic Accommodating Iolsmentioning

confidence: 99%

“…1 Broad categories in managing presbyopia include: spectacles, monovision, surgery on accommodating structures of the eye, multifocal IOLs, and accommodating IOLs. 2 This review focuses on the latter 2 approaches, described as presbyopic IOLs. Technological and design differences are emphasized, and an exhaustive comparison of visual performance is beyond the scope of this article.…”

Section: ' Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Review of Presbyopic IOLs

Gooi

Ahmed²

2012

International Ophthalmology Clinics

View full text Add to dashboard Cite

show abstract

High refractive index polysiloxane as Injectable, in situ curable accommodating intraocular lens

Hao

Jeffery

et al. 2012

Biomaterials

View full text Add to dashboard Cite

Functionalised siloxane macromonomers, with properties designed for application as an injectable, in situ curable accommodating intraocular lens (A-IOL), were prepared via reequilibration of a phenyl group-containing polysiloxane of very high molecular weight with octamethylcyclotetrasiloxane (D4) and 2,4,6,8-tetra(n-propyl-3-methacrylate)-2,4,6,8-tetramethylcyclotetrasiloxane (D4AM) in toluene using trifluoromethanesulfonic acid as a catalyst. Hexaethyldisiloxane was used as an end group to control the molecular weight of the polymer. The generated polymers had a consistency suitable for injection into the empty lens capsule. The polymers contained a low ratio of polymerisable groups so that, in the presence of a photo-initiator, they could be cured on demand in situ within 5 minutes under irradiation of blue light to form an intraocular lens within the lens capsule. All resulting polysiloxane soft gels had a low elastic modulus and thus should be able to restore accommodation. The pre-cure viscosity and post-cure modulus of the generated polysiloxanes were controlled by the end group and D4AM concentrations respectively in the re-equilibration reactions. The refractive index could be precisely controlled by adjusting the aromatic ratio in the polymer to suit such application as an artificial lens. Lens stretching experiments with both human and non-human primate cadaver lenses of different ages refilled with polysiloxane polymers provided a significant increase in amplitude of accommodation (up to 4 D more than that of the respective natural lens). Both in vitro cytotoxicity study using L929 cell lines and in vivo biocompatibility study in rabbit models demonstrated the non-cytotoxicity and ocular biocompatibility of the polymer.

show abstract

Accommodating Intraocular Lenses: Theory and Practice

Cited by 7 publications

References 28 publications

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

Review of Presbyopic IOLs

High refractive index polysiloxane as Injectable, in situ curable accommodating intraocular lens

Contact Info

Product

Resources

About