Complement activation by nylon- and polypropylene-looped prosthetic intraocular lenses

Area of Science:

• Ophthalmology
• Immunology
• Biomaterials Science

Background:

• Cataract extraction with intraocular lens (IOL) implantation can elicit a greater inflammatory response than simple lens extraction.
• Prosthetic IOL components may activate the complement system, generating peptides that mediate acute inflammatory reactions.

Purpose of the Study:

• To investigate the in vitro inflammatory potential of IOLs by examining their ability to activate the human complement system.
• To determine if specific IOL components, such as loop materials, contribute to complement activation and subsequent inflammatory responses.

Main Methods:

• Incubation of normal human serum with various intraocular lenses (polymethylmethacrylate with nylon/polypropylene loops, and polymethylmethacrylate without loops).
• Analysis of serum for complement component C3 and C5 cleavage products using crossed immunoelectrophoresis and single-dimension radioimmunoelectrophoresis.
• Assessment of C5-derived chemotactic activity for human polymorphonuclear leukocytes.

Main Results:

• Polymethylmethacrylate IOLs with nylon and polypropylene loops induced cleavage of C3 and C5 in human serum.
• These looped IOLs generated C5-derived chemotactic activity, indicating the formation of inflammatory mediators.
• Polymethylmethacrylate IOLs without loop supports did not exhibit significant complement-activating or chemotactic activity.

Conclusions:

• Certain intraocular lenses, specifically those with nylon and polypropylene loops, are not biologically inert.
• These IOL components can activate the complement system in vitro, leading to the generation of inflammatory peptides.
• The findings suggest a potential mechanism for the increased inflammatory response observed with some IOLs during cataract surgery.