Abstract
Purpose :
To determine the time required for unfolding with complete optic recovery of a new generation hydrophobic acrylic intraocular lens (IOL) material relative to its base platform and a competitive material.
Methods :
Using a traditional IOL injector delivery system (BLIS, Bausch & Lomb, Rochester, NY), 75 fully-processed, mid-diopter (19.0 to 21.0D, Mean = 20.0D) IOLs of each model (MX60=33, MX60E =33, Acrysof = 9) were delivered into a container of water at incremental temperature conditions in the range of 18°C - 34°C. The temperature was controlled by a recirculating chiller/heater and the water bath temperature was continually monitored via a thermocouple data logger. The time required for each IOL to transition from its injector-folded configuration to a relaxed, unfolded state within the fluid filled bath of varying temperatures was recorded (in seconds) using a timer. Start time was defined as the moment the folded IOL completely exited the injector lumen. End time was defined as the moment IOL recovered to the manufacture’s dimensional specification based on an optic body overlay.
Results :
The average unfolding time at each temperature increment for all hydrophobic acrylic lens materials tested in this study are: MX60 (18°C = >900s, 20°C = >900s, 22°C = 599s, 24°C= 212 s, 25°C = 164s, 26°C = 124, 27°C = 82s, 28°C = 67s, 30°C = 39s, 32°C = 14s, 34°C = 9s), MX60E (18°C = 760s, 20°C = 286s, 22°C = 102s, 24°C= 60s, 25°C = 34s, 26°C = 27, 27°C = 17s, 28°C = 11s, 30°C = 6s, 32°C = 5s, 34°C = 2s), Acrysof (18°C = >900s, 25°C = 33s, 34°C = 3s).
Conclusions :
The unfolding properties of hydrophobic acrylic IOLs are influenced by the material’s glass transition temperature and the temperature of the environment to which they are introduced. Unfolding of the MX60E material was controlled across a wide range of temperatures encountered, with improved unfolding efficiency and optic recovery noted at lower temperatures (18°C to 30°C} compared to MX60. When compared to precursor material found in MX60, the MX60E IOL unfolding is less sensitive to variances in environmental temperature. Unfolding efficiency and time for optic recovery of MX60E was equivalent to that of the Acrysof material across the range of temperatures tested.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.