High refractive index polysiloxane as injectable, in situ curable accommodating intraocular lens

Area of Science:

• Biomaterials Science
• Ophthalmology
• Polymer Chemistry

Background:

• Current intraocular lenses (IOLs) often lack the ability to restore the natural accommodative function of the eye.
• Developing injectable, in situ curable materials for accommodating IOLs (A-IOLs) is crucial for improving vision correction outcomes.

Purpose of the Study:

• To synthesize functionalised siloxane macromonomers for injectable, in situ curable A-IOLs.
• To control polymer properties like viscosity, modulus, and refractive index for optimal lens performance.
• To evaluate the accommodative potential and biocompatibility of the developed A-IOLs.

Main Methods:

• Re-equilibration of phenyl group-containing polysiloxane with specific cyclosiloxanes (D₄ and D₄(AM)) using a catalyst.
• Control of molecular weight using hexaethyldisiloxane as an end group.
• In situ curing via photo-initiation under blue light irradiation.
• Mechanical testing, refractive index measurement, and accommodation amplitude assessment.
• In vitro cytotoxicity and in vivo ocular biocompatibility studies.

Main Results:

• Successfully prepared injectable polysiloxane polymers with tunable viscosity and modulus.
• Achieved rapid in situ curing (within 5 min) under blue light irradiation.
• Demonstrated a significant increase in accommodation amplitude (up to 4 D) in cadaver lenses.
• Confirmed non-cytotoxicity and excellent ocular biocompatibility in rabbit models.
• Precisely controlled refractive index by adjusting aromatic content.

Conclusions:

• Functionalised siloxane macromonomers can be effectively synthesized for A-IOL applications.
• The developed A-IOLs exhibit desirable properties for injection, in situ curing, and accommodation restoration.
• The materials show promising biocompatibility, supporting their potential use in ophthalmic surgery.