New technology for sizing the continuous curvilinear capsulorhexis:: Prospective trial

PURPOSE: To evaluate the deviation of the continuous curvilinear capsulorhexis (CCC) from the target size and shape when a data-injection ring is used. SETTING: University Eye Clinic, Bochum, Germany. METHODS: In a randomized clinical trial, the horizontal and vertical intraoperative and postoperative CCC diameters in 96 eyes having cataract surgery were measured and compared with a 5.1 mm target size. The eyes were randomly assigned to 1 of 2 groups: (1) data-injection ring system, in which a reference ring was projected through the light source of the operating microscope to the anterior capsule surface to guide the CCC procedure, and (2) no data-injection system. The primary clinical endpoint was the identification of a statistically significant difference in CCC diameter and in the scatter around the target diameter between Group 1 and Group 2. RESULTS: No statistically significant between-group differences were found in mean CCC diameter or horizontal and vertical diameter deviation from the target size. Significant differences were found in the scatter around the target CCC diameter. Intraoperatively, the horizontal CCC diameter was within the normal reference range (4.9 to 5.3 mm) in 92% of eyes in Group 1 and 27% of eyes in Group 2 (P <.001). The vertical diameter was within the normal range in 83% and 21%, respectively. Postoperatively, the same tendency persisted (P <=.002). CONCLUSION: Use of the data-injection ring system by an experienced surgeon led to more accurate CCC diameters in relation to the scatter around a reference zone.