Citation: Mira-Agudelo A, TorresSepúlveda W, Barrera JF, et al. Compensation of presbyopia with the light sword lens. Invest Ophthalmol Vis Sci. 2016;57:6870-6877. DOI: 10.1167/iovs.16-19409 PURPOSE. We present the first physiological evaluation of the use of the light sword lens (LSL) for presbyopia compensation. The LSL is an axially asymmetric optical element designed for imaging with extended depth of focus.
METHODS.A monocular visual simulator setup is implemented to measure visual acuity (VA). Physiological presbyopia is ''mimicked'' in human subjects by paralysis of the ciliary muscle, using topical application of a muscarinic antagonist. The effect of a contact lens-configured LSL on the mimicked presbyopia visual system is evaluated by measuring VA as a function of target vergence. The ability of the LSL to compensate presbyopia for 2 photopic luminance values was also analyzed.
RESULTS.The average VA values for 11 subjects suggest that the LSL can compensate for presbyopia across a wide range of target vergences for which the LSL was designed (À3 to 0 D). However, the proposed corrector element causes a loss of distance VA. The mean logMAR VA in that target vergence range was 0.07. The VA curves also show that luminance does not affect the expected behavior of the LSL-corrected presbyopic eye.
CONCLUSIONS.These results indicate that the LSL has significant potential as a visual aid for presbyopia.Keywords: aging changes, ophthalmic optics, presbyopia, vision acuity, visual optics P resbyopia is the decrease in accommodative amplitude of the human visual system that occurs with aging of the eye.
1Although presbyopia is a progressive vision disorder that affects everyone after a certain age, 2 there is no effective way to prevent it. Therefore, over the last 2 decades, important optical investigations have been undertaken to find ways to compensate for this visual condition.Over time, different optical methods to correct presbyopia and restore the ability to recognize both distant and near objects have been proposed.3-6 Some proposals include reading glasses, monovision, residual myopia, multifocal lenses used in glasses, contact lenses, and intraocular lenses. Multifocal intraocular lenses usually are bifocal or trifocal. 7,8 Recent proposals include modifying the topography of the cornea with refractive surgery 4 or inserting a small-aperture (pinhole) implant to artificially reduce the size of the pupil and generate a wider depth of focus.
9Other possible ways to correct presbyopia include varifocal elements based on the Alvarez lenses 10 or programmable lenses based on spatial light modulators, 11,12 which are classified as accommodative lenses. In addition, adjustable lenses that attempt to mimic how the eye lens functions have been designed, 13,14 and changing the optical power by axial displacement of a lens of a fixed focus has also been implanted and tested. 15,16 Despite multiple proposals and scientific advances, there is still no entirely satisfactory way to correct presbyopia. For some p...