Sickenberg M, Gonvers M, van Melle G
Hôpital Ophtalmique Universitaire Jules Gonin, Lausanne, Switzerland.
J Cataract Refract Surg. 1998 Jul;24(7):925-30. doi: 10.1016/s0886-3350(98)80044-8.
To compare the change in continuous curvilinear capsulorhexis (CCC) size after implantation of four types of three-piece foldable intraocular lenses (IOLs) and determine whether initial CCC size and IOL characteristics play a role in the change.
This study comprised 133 eyes that had phacoemulsification and in-the-bag implantation of one of four types of foldable IOLs: Alcon AcrySof MA30BA (n = 36); lovision 127 (n = 29); Mentor ORC MemoryLens (n = 39); Allergan PhacoFlex II (n = 29). Photographs of the CCCs were taken with a digital retinograph 1 day and 6 months after surgery. Using image-analysis software, the CCC surface was measured and changes between 1 week and 6 months were evaluated. Characteristics of the IOLs including overall diameter, optic thickness, and haptic centrifugal force were measured with micrometric tools.
The median change in CCC surface size at 6 months was +5.5% in the lovision group, indicating a slight enlargement. This finding was significantly different from that in the other three IOL groups (P < .0001), which had a tendency toward CCC contraction. Median change in CCC size was -2.3% in the MemoryLens group, -2.8% in the AcrySof group, and -6% in the PhacoFlex group. The MemoryLens was the most predictive IOL, with the smallest standard deviation; it was the only group in which no patient developed CCC contraction of more than 10%. Although the lovision and PhacoFlex IOLs have common physical characteristics except for optic thickness (lovision 30% thicker), the CCCs in the lovision group were significantly more stable (P < .0001). Results indicate that the high centrifugal haptic force associated with acrylate/methacrylate polymer optics of the AcrySof and MemoryLens IOLs may prevent CCC contraction of greater than 10% in 97.4% of cases.
Although there were statistically significant differences, patients in all four three-piece foldable IOL groups had good CCC stability. However, the more stable and predictable CCCs were in the IOL groups that had the strongest centrifugal haptic force and an acrylate/methacrylate polymer optic (AcrySof and MemoryLens).
