Trans-Conjunctival Laser Delivery For Scleral Elastomodulation In Accommodation Restoration

Scleral elasticity increases with age and contributes significantly to the loss of accommodation. While the crystalline lens also becomes more elastic with age, it’s elastic rigidity lags behind that of the sclera, making the sclera a better target tissue in presbyopic eyes. In this study, we aim to restore accommodation by changing the elastic modulus of the sclera with a non-invasive, mid-IR laser.

Laboratory: Senogen GmbH, Palo Alto, CA, USA

A 1.55 um battery operated diode laser can be mounted onto a slit lamp for non-contact delivery of a laser annulus pattern (4 quadrants, 12-18 mm) onto the anterior sclera. Finite element modeling of non-destructive scleral shrinkage and increasing scleral compliance are optimized and tested on multiple pig and cadaver eyes with OCT and OCE verification of safety and effectiveness. Clinical validation with non-contact delivery of a 2.1 um precursor wavelength in 150 eyes using a similar pattern was performed with ethics approval to demonstrate clinical safety and efficacy with one year follow up of DCNVA, UNVA (Jaeger), and IOP. Further clinical studies with the optimized 1.55 um laser wavelength are underway.

With the 1.55 um laser wavelength, FEM simulations and ex-vivo testing with pilocarpine confirms a 250 um forward and inward movement of the ciliary body in cadaver eyes. OCT data shows a uniform depth of tissue-modifying specular reflection, and OCE shows up to a 50% reduction in elastic rigidity in porcine and cadaver sclera. Clinically at 2.1 um, no adverse events were reported on all 150 patients, and near vision improved from J11 to J3 at the last follow-up of 12 months. Additional clinical efficacy and safety of the 1.55 um wavelength will be reported.

Mid-Infrared laser scleral modulation and ciliary body translocation in aging eyes shows promise as a low cost, portable method of achieving extra-lenticular accommodation restoration. The global implications of providing such a low cost, portable therapy makes it of special interest in the quest to reduce the worldwide burden of visual impairment.