A Novel Dual-wavelength, Dual-function Laser System for Presbyopia and Glaucoma Treatments

Abstract

Purpose: To update the accommodation mechanisms and propose a dual-wavelength, dual-function laser system for presbyopia and glaucoma treatments. Study Design: Laser sclera softening (LSS) for increased accommodation of presbyopic eyes. Place and Duration of Study: New Taipei City, Taiwan, between Jan., 2023 and Feb., 2023. Methodology: Accommodation gain (AG) can be improved by: (i) thermal shrinkage of the           scleral stroma and ciliary body, or (ii) softening of the scleral stroma (with temperature                    range of 700C to 900C), such that the the lens front and back curvature change (or lens               thickening), leading to the thickening of ciliary body and its apex, and the increase of the space of ciliary body and lens equation (SCL), and the length of the posterior vitreal zonules (PVZ) increases. Results: A novel dual-color laser system having wavelength A and B, acting on the front-zone and back-zone of the sclera, respectively, where laser-A has a deep thermal penetration the sclera and ciliary body (CB) (0.5 to 1.0 mm); and laser-B has a shallow penetration depth in the sclera (0.3 to 0.5 mm), based on the optical property of the sclera. Laser-A (having a wavelength about0.8 to 0.98 um) leads to thermal shrinkage of the ciliary body such that the CLS is increased for accommodation gain which is much more effective than the prior art. Conclusion: The increase of AG can be achieved by scleral softening and ciliary body shrinkage which increase the SCL. A proposed novel dual-color laser system acting on the front-zone and back-zone of the sclera, respectively, could provide higher AG than that of single wavelength, or prior arts using scleral ablation. However, further clinical studies are required to justified the proposed novel system with predicted advantages and efficacy based on the optical properties of sclera.