Long-term Study of Posterior Capsular Opacification Prevention With Endocapsular Equator Rings in Humans

Abstract

Objective: To confirm the effect of a square-edged, closed endocapsular equator ring (E-ring) for preventing posterior capsular opacification (PCO) after cataract extraction. Methods: Fifty-one eyes underwent cataract surgery associated with E-ring implantation between October 2002 and March 2008. Group 1 included 14 patients (14 eyes) who received an E-ring and intraocular lens (IOL) in 1 eye before March 2006. Their fellow eyes received only an IOL as controls. Group 2 included 23 patients (37 eyes) who received an E-ring and IOL in 1 or both eyes after March 2006 and another 37 age-matched control eyes with only IOL implants. After cataract removal, the E-ring (1.0 mm wide and thick and 9.0 or 9.5 mm long) was implanted in the capsule and an IOL was fixed in the ring. In the control eyes, only an IOL was implanted. The follow-up periods were 2 to 7 years. The PCO value was determined using the Hayashi method. Results: Two years postoperatively in group 1, the PCO value in the central area of the eyes with an E-ring was significantly lower than in the controls (4.4 vs 11.4, respectively; P=.005). No eyes with an E-ring required Nd:YAG laser posterior capsulotomy postoperatively compared with 23 of 51 control eyes (45%). The posterior capsule in the eyes with an E-ring remained transparent without touching the IOL optic. The 9.5-mm ring fit all eyes. Conclusion: The 9.5-mm E-ring, which fit all eyes, prevented PCO in human eyes 2 to 7 years postoperatively.

Posterior capsular opacification in highly myopic eyes with an endocapsular equator ring

“…E-rings prevent posterior movement of the postoperative metamorphosed lens epithelial cells (LECs) at the equator [2,3], thus preventing PCO that requires capsulotomy [4,5].…”

“…However, no capsulotomies are required among eyes with myopia exceeding -12.5 D, despite longer followup periods. PCO posterior capsular opacification, D diopters Table 1 Preoperative and postoperative data from six eyes with extensive posterior capsular opacification after implantation of an E-ring Mean ± SD 51 ± 6.8 corneoscleral incisions as reported previously [5]. The average time of the initial surgery was 9 ± 1.6 min.…”

“…The device is a closed flexible silicone ring with a square edge that prevents posterior movement of the metamorphosed lens epithelial cells at the equator. Following studies of E-ring implantation in rabbit [2], monkey eyes [3], and a human eye [4], we reported the clinical results from 51 eyes in 2011 [5]. Despite the closed construction of the ring, only one size with an outer diameter of 9.5 mm was used for all cases.…”

“…Various values were measured in the same manner as reported previously [5]. The ocular axial length was measured using a non-contact optical device (IOL Master version 5, Carl Zeiss Meditec Co. Ltd., Tokyo, Japan).…”

“…Neodymium-doped yttrium aluminium garnet (Nd:YAG) laser capsulotomy was performed when the patients had considerable visual disturbances. The capsulotomy was performed in the same manner used for control eyes [5]. Patients were followed for at least 2 years (average, 44 ± 12.1 months; range 23-64 months), with the exception of one eye followed for 23 months.…”