Changes in Cut Surface and Weight of Colored Acrylic IOLs After Severe Accelerated Deterioration Test
Narrative Responses:
Purpose
We previously reported that long-term immersion of intraocular lenses (IOLs) in water at high temperature leads to their opacification and deterioration, depending on differences in materials. This study aimed to examine changes in the cut surface and weight of colored acrylic IOLs.
Methods
Colored IOLs manufactured by various companies were immersed in 50-mL screw-tube bottles containing ultrapure water at 100°C for 115 days (equivalent to 20 years). External appearance and cut surfaces were observed before and after drying of the IOLs, and then percent changes in weight before and after treatment were determined. IOLs used: We used 3 colored IOLs of each of the following 5 types manufactured by different companies & hibar; SN60WF (Alcon) and AN6K (KOWA) by the cast-molding method and NY-60 (HOYA), NX-60 (Santen), and NS-60YG (NIDEK) by the lathe-cut method.
Results
External appearance: Opacification was observed to a varying degree in all IOLs except AN6K and NX-60. After drying at a room temperature of 25°C for 48 hours, opacification disappeared in all IOLs except SN60WF. Cut surfaces: Opacification was observed to a varying degree for all IOLs. After drying, opacification was observed in all except NS-60YG. Percent changes in weight: Weight before the deterioration test was 16.0 – 18.6 mg. The changes after drying were -1.5% for SN60WF, -9.8% for AN6K, -2.7% for NY-60, -3.7% for NX-60, and -1.5% for NS-60YG.
Conclusion
Although no opacification was observed on the external appearance of AN6K and NX60, there was slight opacification on the cut surfaces. Percent changes in weight of AN6K (decreased to -9.8%) may be attributable to different methods of manufacturing acrylic resin.