Evaluation of iris color stability in ocular prosthesis

Area of Science:

• Ocular prosthetics
• Materials science
• Colorimetry

Background:

• Accurate iris reproduction is crucial for esthetic ocular prostheses.
• Anophthalmic patients require prostheses that closely match their remaining eye.
• The longevity of ocular prostheses depends on the color stability of the prosthetic iris.

Purpose of the Study:

• To evaluate the color stability of acrylic paints used in ocular prostheses.
• To analyze the impact of acrylic resin polymerization temperature on paint stability.
• To assess the effect of ultraviolet (UV) radiation on paint colorfastness.

Main Methods:

• Fabrication of prosthetic iris specimens in blue, yellow, black, brown, and green.
• Colorimetric readings before and after polymerization cycle simulation.
• Accelerated aging assay using UV-A radiation over 3 weeks with weekly colorimetric readings.
• Statistical analysis including Levine's test, Student's t-test, and Friedman's test.

Main Results:

• Yellow paint showed clinically unacceptable color change (Delta E* > 3.3) after polymerization.
• Accelerated aging resulted in statistically significant color changes over time for green, brown, black, and blue paints (p<0.05).
• Brown and black paints remained within clinically acceptable limits after aging; green was slightly above, and blue showed significant degradation.

Conclusions:

• Yellow paint's color stability was not compromised by accelerated aging.
• Green paint exhibited degradation slightly exceeding clinical acceptability.
• Blue paint showed significant, clinically unacceptable degradation over time, while brown and black paints remained stable.