Purpose: Closed 9.5-mm-diameter endocapsular equator rings (E-rings) prevent posterior capsular opacification (PCO). However, in our research, some highly myopic patients unexpectedly developed late, extensive PCO that required capsulotomy. We also report for the first time how the capsule reacted to neodymium-doped yttrium aluminium garnet (Nd:YAG) laser shots.
Methods: Sixty-two eyes (39 patients; average age, 48 ± 13.2 years) were implanted with a closed, square-edged silicone E-ring (outer diameter, 9.5 mm) and an intraocular lens between April 16, 2008, and November 30, 2011.
Results: During the postoperative, minimal 2-year follow-up, PCO requiring Nd:YAG laser capsulotomy developed in six (9.7 %) of 62 eyes, of which five had -8.75 to -12.5 diopters (D) of myopia preoperatively. The axial lengths of those eyes ranged from 25.86 to 29.97 mm. However, none of the 13 eyes with higher myopia had severe PCO that required capsulotomy. All capsulotomies were performed uneventfully.
Conclusion: The standard 9.5-mm-diameter closed E-ring does not prevent extensive PCO in eyes with preoperative myopia ranging between -8.75 and -12.5 D and an axial length between 25.86 and 29.97 mm. Posterior capsulotomies were performed safely. Further study is needed to determine why PCO did not occur in more high myopic eyes (larger axial length eyes).
Keywords: Capsulotomy; Endocapsular equator ring; Nd:YAG laser; Posterior capsular opacification.