The Potential Role of the Light Adjustable Lens in Flanged Intrascleral Haptic Fixation

Abstract

Purpose: To compare maximum tensile strength between commonly used 3-piece intraocular lens (IOL) for flanged intrascleral haptic fixation (FISHF). Setting: Willis-Knight Eye Institute Design: Laboratory investigation Methods: Haptic tensile strength was compared with MA60AC, CT Lucia 602, AR40E, and the light-adjustable lens (LAL). Haptic strength with a 24D (diopter) IOL was compared across all lenses, as well as a range of 10-30D with the MA60AC. A custom device was created to hold the IOL in correct haptic orientation. The max tension (mean +/- standard deviation) was recorded in newtons (N) when the haptic lost tension or broke. Results: CT Lucia was the strongest at 1.53 +/- 0.11 N vs 1.00 +/- 0.15 (MA60AC), 0.87 +/- 0.19 (AR40E), and 0.83 +/- 0.14 N (LAL), P<0.001. The LAL and AR40E were similar to a 9-0 polypropylene suture while being significantly stronger than 10-0 polypropylene suture, P<0.001. No difference in haptic tension for the MA60AC from 10-30D, P>0.05. High magnification revealed the highest haptic fractures for MA60AC at 40% compared to LAL, AR40E, and CT Lucia at 0%. CT Lucia and AR40E had 100% of haptics disinserted from the IOL without any damage compared to 60% LAL and 60% MA60AC. CT Lucia, AR40E, and LAL have a flatter haptic angulation at 5 degrees. Conclusion: Haptic strength, durability, and angulation of the LAL may support the possibility of FISHF in the hands of experienced surgeons. However, further testing is strongly recommended to verify if physiologic conditions or light treatments may compromise long-term haptic stability.