Intraocular Photobonding to Enable Accommodating Intraocular Lens Function

Abstract

PurposeAccommodating intraocular lenses (A-IOLs) require capturing the ciliary muscle forces. Prior work demonstrated strong photo-initiated bonding between strips of capsular bag and poly(2-hydroxyethyl methacrylate); (pHEMA) polymer in an extraocular setting. We demonstrate that photobonding can be achieved intraocularly.MethodsPhacoemulsification was performed in porcine eyes (<24 hours postmortem). A commercial intraocular lens (IOL; pHEMA-MMA material) was inserted in the capsular bag. Surface contact between the lens and capsular bag was ensured by continuous air infusion into the anterior chamber of the eye, which provided sufficient pressure at the interface, as well as oxygen. The capsular bag and IOL then were stained with 0.1% photosensitizer Rose Bengal (RB) solution. A fiberoptic probe connected to a diode-laser (532 nm) was used to locally irradiate the capsular bag–IOL interface intraocularly. The bonding breaking load was evaluated in a uniaxial stretcher.ResultsPhotobonding occurred in the 0.8 to 1.6 W/cm2 irradiance range and 2.5 to 7 minutes irradiation time. Average forces of 0.12 N stretched but did not break the bond. These forces, applied uniaxially, are higher than the summed net accommodating force of the ciliary muscle along the entire equator (0.08 N). In two cases, the zonulae broke before the bonded region.ConclusionsPhotobonding between the capsular bag and IOL polymer can be achieved intraocularly, in a procedure compatible with standard cataract surgery. This technique will enable the mechanisms of A-IOLs not to rely on capsular bag integrity or natural haptic fibrosis.Translational RelevanceIntraocular photobonding holds promise to enable operation of A-IOLs to restore accommodation in presbyopia, affecting 100% of the population >45 years old. Intraocular bonding of polymer material to ocular tissue also may find other applications in ophthalmology.

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“…PTB is commonly mediated through green light and photoactive dyes such as rose bengal, which when photoactivated, facilitate amino acid crosslinking reactions mainly through the production of singlet oxygen . This repair method has shown to be valuable in a variety of surgical procedures involving the skin, eye, blood vessels, and vocal cords . However, using the dye alone with green light often does not provide enough mechanical strength in some procedures without extra support from grafts or sutures. , This disadvantage is also shared with many of the commercially available tissue adhesives, which have poor mechanical properties under high tensile loads .…”

Design and ex situ performance of a shape-changing accommodating intraocular lens

“…Rose Bengal photobonding (RBPh) had been shown to be effective for sealing corneal incisions [22] and for bonding amnion to the cornea [23]. We have shown that it is possible to use this photo-activated technique to bond polymers such as those typically used for contact lens and IOL manufacturing to capsular tissue [24] as well as full intraocular lenses following phaco-emulsification in a porcine eye model [25].…”

Optical imaging technologies and opto-biomechanical models for diagnostics and customized treatment in ophthalmology

“…Using the same photosensitizer and green light source, a hydrophilic polymer sample stained with Rose Bengal and in contact with capsular bag tissue can be quickly (5-10 min) bonded to the capsular bag, with recorded maximum forces higher than those found in the accommodative apparatus. The efficacy and viability of this method to bond hydrophilic polymer strips and entire commercially available IOLs to the capsular bag has been demonstrated, both ex vivo (Marcos et al, 2015) and intraocularly, in a porcine eye model, following cataract surgery procedures (Alejandre-Alba et al, 2018).…”