Evaluation of the performance of accommodating IOLs using a paraxial optics analysis

Ale, Jit; Manns, Fabrice; Ho, Arthur

doi:10.1111/j.1475-1313.2009.00694.x

Cited by 6 publications

(7 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Near vision after implantation of 1E-AIOL reported in the literatures 22–25 is higher than expected from theoretically predicted accommodation 26–29 . Clinical intuition might attribute such improved performance to extension of the range of near vision due to improved depth of field.…”

contrasting

confidence: 49%

“…We have used this eye model in earlier studies to evaluate the accommodative performance of AIOLs 26,27,32 . The Navarro eye model consists of ocular parameters that are accommodation dependent and could facilitate comparison of the results between the phakic and pseudophakic conditions.…”

Section: Methodsmentioning

confidence: 99%

“…Both variants employed a positive powered front lens element and a negative power back lens element as these power combinations have been shown to provide the best accommodative efficiency (change in power versus distance of lens translation) as well as providing ‘positive’ accommodation (i.e. the AIOL increases in power as the lens elements separate 26,27 . For the front element mobile model, the stationary back element is located at the back reference plane.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Paraxial Analysis of the Depth of Field of a Pseudophakic Eye with Accommodating Intraocular Lens

Ale¹,

Manns²,

Ho³

2011

Optometry and Vision Science

Self Cite

View full text Add to dashboard Cite

Purpose To investigate the depth of field of pseudophakic eye implanted with translating-optics accommodating Intraocular lenses (AIOLs). Methods Theoretical analyses using paraxial optics equations were used. The crystalline lens in the Navarro eye model was replaced with an AIOL modelled as a thin-lens system with either a single lens element (1E-AIOL) or two-element (2E-AIOL). To quantify the depth of field, a reference limit for retinal blur circle diameter was adopted from typical values of depth of field of the normal eye. Effect of various factors including AIOL type, lens element power, implant position and pseudophakic accommodation on depth of field were analysed. Results Depth of field increased with more posterior positioning of the AIOL and decreased with pseudophakic accommodation by translation of optics. However, the changes did not exceed 0.02 D over the range of factors tested. Effective depth of field, defined as the magnification adjusted depth of field, is relatively independent of the implant position and power combination of AIOL. Effects of varying design factors on the depth of field of AIOL are too small to be clinically observable. Conclusions While depth of field extends the range of near vision with AIOL, varying design and surgical factors such as depth of implantation and optical power of lens element(s) within clinically practical limits modifies depth of field by an insignificant amount. In the practical sense, attempting to enhance the depth of field of AIOL by varying design factors such as the position of implantation would be unrewarding.

show abstract

contrasting

confidence: 49%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Paraxial Analysis of the Depth of Field of a Pseudophakic Eye with Accommodating Intraocular Lens

Ale¹,

Manns²,

Ho³

2011

Optometry and Vision Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…It has also become a popular tool in ray‐tracing analyses of astigmatic 21,22 and aspheric surfaces 23 . This approach affords an elegant means of obtaining closed‐form analytical equations to evaluate the performance of AIOLs, avoiding tedious algebraic developments 24 . In the present study this method was used to evaluate the angular and lateral magnifications of a pseudophakic model eye.…”

Section: Methodsmentioning

confidence: 99%

“… 34 was used. This model eye was chosen as it has been used previously to evaluate accommodative performance of the AIOL 16,24 and therefore provides a convenient comparative reference. The model eye parameters are given in the Appendix S1 (available with the online version).…”

Section: Methodsmentioning

confidence: 99%

Magnifications of single and dual element accommodative intraocular lenses: paraxial optics analysis

Ale

Manns

2010

Ophthalmic Physiologic Optic

Self Cite

View full text Add to dashboard Cite

Purpose: Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Methods: Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM 1 ) or pseudophakic (rLM 2 ) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Results: Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM 1 and rLM 2 increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Conclusion: Power of the mobile element, and amount and direction of the translation (or the achieved accommodative amplitude) are important parameters in determining the magnifications of the AIOLs. The results highlight the need for caution in the prescribing of AIOL. Aniso-accommodation or interocular differences in AIOL designs (or relative to the natural lens of the contralateral eye) may introduce dynamic aniseikonia and consequent impaired binocular vision. Nevertheless, some designs, offering greater increases in magnification on accommodation, may provide enhanced near vision depending on patient needs.

show abstract

Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: Optical performance and clinical outcomes

Tomás-Juan¹,

Murueta‐Goyena

2015

Journal of Optometry

View full text Add to dashboard Cite

Presbyopia occurs in the aging eye due to changes in the ciliary muscle, zonular fibers, crystalline lens, and an increased lens sclerosis. As a consequence, the capacity of accommodation decreases, which hampers to focus near objects. With the aim of restoring near vision, different devices that produce multiple focuses have been developed and introduced. However, these devices are still unable to restore accommodation. In order to achieve that goal, dual-optic accommodating Intraocular Lenses have been designed, whose anterior optic displaces axially to increase ocular power, and focus near objects. Although dual-optic accommodating IOLs are relatively new, their outcomes are promising, as they provide large amplitudes of accommodation and a greater IOL displacement than single-optic accommodating IOLs. The outcomes show comfortable near vision, higher patients' satisfaction rates, and minimal postoperative complications like Posterior Capsular Opacification and Anterior Capsular Opacification, due to their design and material.

show abstract

Evaluation of the performance of accommodating IOLs using a paraxial optics analysis

Cited by 6 publications

References 38 publications

Paraxial Analysis of the Depth of Field of a Pseudophakic Eye with Accommodating Intraocular Lens

Paraxial Analysis of the Depth of Field of a Pseudophakic Eye with Accommodating Intraocular Lens

Magnifications of single and dual element accommodative intraocular lenses: paraxial optics analysis

Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: Optical performance and clinical outcomes

Contact Info

Product

Resources

About