97th DOG Annual Meeting 1999
DO LARGE POSITIONING HOLES IMPROVE THE STABILITY OF ENDOCAPSULAR FIXATION?
A PROSPECTIVE, RANDOMIZED STUDY WITH TWO TYPES OF PLATE-HAPTIC INTRAOCULAR LENSES
O. Schwenn, U. Kottler, B. Dick, N. Pfeiffer
Purpose: Luxation, decentration and rotation of plate-haptic silicone intra-ocular lenses (IOLs) with small positioning holes have been described. A larger positioning hole may ensure a securely fixed postion due to capsular synechia or proliferation of lens epithelial cells through the hole. Especially for the use of plate-haptic toric IOLs, a stable fixation without postoperative rotation is important.
Patients and Methods: In a prospective, randomized study 51 Chiroflex C10 (size of positioning hole: 0.3 mm) and 56 C11 (size of positioning hole: 1.15 mm) IOLs were implanted. IOL position at the end of the operation was recorded. Lens position was photodocumented by retro-illumi-nation and Scheimpflug images one day and five months post-operatively. Ultrasound biomicro-scopy of the positio-ning holes was performed at 5 months.
Results: On the first postoperative day no IOL of either group was decentered more than 1.0 mm. On follow up, 33% (13/39) of the C10 IOL showed a decentration of 0.5-1.0 mm and 13% more than 1.0 mm (5/39, max. 1.23 mm). In the C11-group, 45% (21/47) of the implants were decentered 0.5-1.0 mm and 9% more than 1.0 mm (4/47, max. 1.41 mm). Compared to the intraoperative status, 25% of the C10-group (12/47) and 36% of the C11-group (19/53) demonstrated a rotation of more than 20°. No tissue or capsular adhesion was detectable in the plate haptic holes in the majority of both groups using ultrasound biomicroscopy.
Conclusion: The enlarged positioning hole did not prevent IOL-decen-tration or rotation. Therefore, we recommend not to use currently available toric silicone IOLs with plate-haptics for astigmatic correction .
Department of Ophthalmology, University of Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany