The IOL and haptics are made of a hydroxyethyl methacrylate-polyethylene glycol phenylether acrylate–styrene copolymer that is cross-linked with ethylene glycol dimethacrylate. This structure is unique in that the IOL is made of a hydrophobic material that was approved by the FDA as being free of glistenings, and is believed to be the only IOL hydrophobic material to have such a claim.
The lens comes packaged in 0.9% sterile saline solution to maintain its water content in equilibrium. It is this feature that is believed to prevent glistening formation. The lens has water content of 4%, in contrast to other hydrophobic IOLs in which the water content ranges from 0.35% to 0.5%. The IOL has a high refractive index of 1.54 and a low affinity for silicone oil.
The IOL also has a high V number (40.5), which is higher than that of the AcrySof IOL (Alcon Laboratories) V number (37.58).
Dr. Packard, a consultant surgeon at Prince Charles Eye Unit, Windsor, England, said that the higher the V number, the less chromatic aberration and the better the resultant retinal image quality.
This IOL has a single-piece lens, an aspheric optic, a square posterior edge, and modified-C haptics. This design, with a 360° square posterior edge and a close capsular connection, is specifically intended to minimize the development of posterior capsule opacification (PCO) .
The lens has a 6-mm-diameter optic and is 12.5 mm in overall diameter.
"The aspheric, aberration-free optic delivers enhanced contrast sensitivity; uniform power, center to edge; and better visual acuity," Dr. Packard said.
IOL powers range from 0 to +34 D. The 0- to +10-D lenses and the +30- to +34-D lenses increase in 1-D increments, and from +10 to +30 D they increase in 0.5-D increments. The IOL is prehydrated, and because it is in equilibrium, the polymer does not gain or lose water.
"The material is stable, so excess water cannot accumulate," Dr. Packard said. "This eliminates the driving force for long-term water exchange when the lens is implanted."