Efficacy of equator rings in an experimental rabbit study
T. Hara, T. Hara, K. Sakanishi and Y. Yamada
Hara Eye Hospital, Utsunomiya, Japan.
OBJECTIVE: To determine the efficacy of the equator ring in maintaining the
circular contour of the capsule bag equator and transparency of the
posterior capsule after crystalline lens extraction in 12 rabbit eyes.
METHODS: After phacoemulsification through a 5-mm window made by continuous
circular capsulorrhexis in the central anterior capsule, a flexible
silicone ring (outer diameter, 11.0 mm; width, 1.5 mm; and thickness, 1.5
mm) was implanted in the capsule in seven rabbit eyes. A 13.0-mm
Sinskey-style posterior chamber intraocular lens was then implanted inside
the ring. Three other eyes received only equator rings, and two others
received only intraocular lenses. Eyes were followed up for 3.5 +/- 1.4
months (mean +/- SD) before enucleation and evaluation by stereomicroscopy;
they then underwent light microscopic examination. RESULTS: The two eyes
that received only the intraocular lens had equatorial distortion and
severe posterior capsule opacification. In nine (90%) of the 10 eyes that
were implanted with the rings, the circular contour of the equator was
preserved, and seven (70%) of these 10 eyes had transparent posterior
capsules. CONCLUSION: Implantation of the equator ring effectively
maintained the circular contour of the capsule bag equator and inhibited
cells at the bag equator from proliferating toward the center of the
posterior capsule in the rabbit.
