![]() ![]() 18 The test lenses demonstrated reasonable myopia control with slowing of myopia progression by 59 percent and 74 percent (spherical equivalent) and reduction in axial length elongation by 33 percent and 50 percent. lenses) incorporating “Light diffusion technology” has a clear central aperture surrounded by multiple dots that reduce the peripheral retinal contrast by at least one-third to half (30 percent to 60 percent) compared to central or on-axis contrast. ![]() 17 This novel spectacle lens design ( SightGlass Vision D.O.T. 16Īdditionally, this decade also saw a new myopia management technology offering from SightGlass Vision, Inc., through contrast reduction. technology comprises a group of aspherical lenslets on 11 rings surrounding a clear central distance correction zone that is said to produce a volume of myopic defocus signal in front of the retina. (Highly Aspherical Lenslet Target) technology to control myopia progression. 16 The Stellest lens is said to incorporate H.A.L.T. The latest entrant in the world of myopia management using spectacle lenses is Essilor’s Stellest spectacle lens, which in comparison to single vision lenses, is reported to slow myopia by approximately 63 percent for spherical equivalent refractive error and approximately 64 percent for axial length. The multiple segments induce myopic defocus in front and at the retina periphery while simultaneously providing clear central vision. 14 Each segment is approximately 1mm in diameter. spectacle lens has around 400 multiple segments of plus powered lenslets (+3.50D) in the mid-peripheral portion of the spectacle lens surrounding a clear central zone for distance refractive correction. or Defocus Incorporated Multiple Segments spectacle lenses (MiyoSmart by HOYA) reportedly slow myopia by 52 percent (spherical equivalent) and axial length by 62 percent compared to single vision spectacles. 13Īlthough these first-generation lenses with continuous power profiles found limited success, 10 they spurred significant research in this area. ![]() 13 These lenses were designed to reduce both lag of accommodation and hyperopic defocus in the peripheral retina. Likewise, positively aspherisized PALS with add power (+1.50 D) reduced myopia progression by 20 percent compared to single vision spectacle lenses. 12 These lenses also have an extended area of distance correction in the lower portion with no additional power. 11 These lenses have distance correction at the center for clear central vision with asymmetric design at the periphery incorporating continuous plus power for altering peripheral optics. ![]() 10 A reduction in myopic progression by 15.4 percent (spherical equivalent) and axial length elongation by 13.9 percent was observed with these lenses in this subgroup of participants. Utilizing this strategy, the first-ever trial designed and tested three designs for peripheral defocus management but found only one design to provide reasonable control in a subgroup of children with parental myopia. 11 These strategies were based on inducing relative myopic defocus or reducing relative hyperopic defocus at the retinal periphery. 9įrom 2010 onward, there was a shift toward developing and testing myopia management devices that altered peripheral retinal defocus based on landmark studies that found that peripheral retina had a significant role in emmetropisation and refractive error development. 7 Executive bifocal spectacle lenses incorporated with base-in prism are available in many countries. 6, 8 An exception was executive bifocals with and without base-in prism that reduced myopic progression by approximately 51 percent (spherical equivalent) compared to single-vision spectacles. 1 2, 3 Bifocals and progressive addition lenses (PALs) were found effective only in few categories, such as those with a larger lag of accommodation 4-7 or faster myopia progression in myopia. Although undercorrection was widely practiced, it was shown to increase myopia progression. Up until 2010, the only options available to control myopia with spectacle-based strategies were progressive addition or bifocal spectacles. By Krupa Philip, PhD, Brien Holden Vision InstituteĪlthough 2020 is a year that many will consider as best forgotten or relegated to history, for spectacle-based myopia management strategies, it marks the end of a decade of rapid and significant improvements to slow myopia. ![]()
0 Comments
Leave a Reply. |