Categorization and Surgical Techniques of Weak Zonule Based on Findings at Capsulorhexis during Cataract Surgery
Journal of Clinical & Experimental Ophthalmology
Purpose: We categorize weak zonule during capsulorhexis. Design: Retrospective interventional case series. Methods: The study examined 5447 consecutive eyes of 3527 cases that underwent phacoemulsification (PEA) and intraocular lens (IOL) implantation between March 2006 and March 2014 at Showa University Fujigaoka Hospital, Kanagawa, Japan. Weak zonule was categorized based on findings at capsulorhexis and difficulty in performing continuous curvilinear capsulorhexis (CCC). The categorization
... he categorization definitions were as follows: (1) Group N (normal) with no or slight lens movement at the start of the CCC and no difficulty in performing CCC, (2) Group W (weak) with moderate lens movement frequently accompanied by fold formation during CCC and some difficulty in performing CCC, (3) Group VW (very weak) because of severe lens movement and difficulties with the initial puncture, CCC can be performed with the aid of a highly retentive and cohesive ophthalmic viscoelastic device (OVD; Healon 5 ® ), and (4) Group EW (extremely weak) with zonular deficiency in addition to the Group VW criteria and accounted for the cases of severe phacodonesis, lens subluxation, lens luxation into the anterior chamber, and dropped nucleus into the vitreous cavity that could be categorized preoperatively. We examined capsule stabilization device use during PEA, surgical lens removal, and IOL fixation in each group. Results: We defined 5098 eyes as Group N, 251 eyes as Group W, 55 eyes as Group VW, and 43 eyes as Group EW. As the zonule became weak, the use of the capsule stabilization device increased in PEA and intracapsular cataract extraction, and scleral suture fixation of IOL increased. Pars plana vitrectomy for lens removal was performed in 5 eyes (11.63%) categorized as Group EW. Conclusions: The categorization of weak zonule at CCC may be useful for selecting an appropriate capsule stabilization device and procedure during cataract surgery.