Bimanual implantation of the capsular tension ring: minimizing capsular stress, optimizing surgical outcome and efficacy

Editor, The development of capsular tension rings (CTRs) (Hara et al. 1991; Legler et al. 1993; Nagamoto & Bissen-Miyajima 1994) has made phaco surgery safer. The function of the CTR is to stretch the capsule. This is achieved by the fact that the outer circumference of the CTR is greater then the circumference of the capsular bag. As the average diameter of the capsular bag is considered to be 10.6 mm (Legler et al. 1993), even a small CTR with a diameter of 12 mm expands the capsular bag, stretching it to the periphery, that is, to the capsular equator. Various designs and applications of CTRs were recently reviewed (Menapace et al. 2000; Hasanee et al. 2006). No in-depth study describing the potentially dislocating effects of CTR insertion is currently available. Most common current insertion methods implant the CTR in its totally relaxed form. These include the single-handed insertion technique, which exposes the capsular bag to considerable stress in the horizontal and antero-posterior planes. This may cause significant traction on the zonulae, with a temporary risk of overstretching them. Most techniques involve the simple mono-manual insertion of the CTR through the cataract incision with or without an injector. This has replaced the initial hand-over-hand technique referred to by Gimbel & Sun (2002). We report on a modified, bimanual implantation technique, which appears to enhance the stability of the capsular bag during CTR insertion. It has so far been used in more than 60 cases and has proved to be easy, quick and effective. The implant is held bimanually (Fig. 1) and gently rotated into the bag (Fig. 2), avoiding any actual contact with the capsule. When the leading loop held by the Sinskey hook overlaps the end loop held by the forceps, both should be released at the same time (Fig. 3). This exposes the capsular bag to an instant and even 360° centrifugal force. The edge of the initial hole is held with the Sinskey hook. The edge of the initial hole is held with the Sinskey hook while the body of the ring is slid gently into the bag. Positioning the outer hole with the forceps inside the edge of the capsular bag. This bimanual CTR insertion technique is reliable and safe and should be considered along with the use of iris retractors for capsular bag fixation and the slow-motion phacoemulsification approach (Osher 1993) when weak zonules are present. The method can also be applied when using an injector, which may be beneficial as it avoids the contamination of the CTR by the ocular surface. In its current form, this method can probably only be used after removal of the crystalline lens in an empty capsular bag. We have now successfully tested the method in cases where the CTR needs to be implanted earlier in the cataract procedure.