Mini-haptics to improve capsular fixation of plate-haptic silicone intraocular lenses

Purpose: To evaluate the effects of a new mini-hepatic design on the strength and stability of capsular bag fixation of plate-hepatic silicone intraocular lenses (IOLs) and determine whether this design encourages the growth of regenerating lens material or fibrous tissue around the hepatic biomaterial and thus improves lens fixation in the capsular bag. Setting: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Department of Ophthalmology, Charleston, South Carolina, USA. Methods: Six rabbits had bilateral continous curvilinear capsulorhexis, phacoemulsification, and plate-hepatic silicone IOL implantation. Each rabbit had a small-hole plate IOL (Chiron C10UB) implanted in the right eye and a mini-hepatic plate IOL (Chiron C40UB) in the left eye. All rabbits were killed at 2 months. The force required the extract one haptic from the capsular bag was measured with a digital force gauge. Histopathologic analysis was performed on all specimens. Results: The mini-hepatic style IOLs required significantly more extraction force than the small-hole design (P = .011). Histopathologically, proliferating lens epithelial cells were observed growing circumferentially around the mini-haptics, causing a 360 degree synechia formation. This formation did not occur with the conventional small-hole plate IOLs used as the control. Conclusions: Lens epithelial cell proliferation around the mini-haptics significantly improved capsular bag fixation of the plate-haptic silicone IOL. This should decrease the incidence of clinical decentration and dislocation.