R Sun1, H V Gimbel. 1. Gimbel Eye Centre, Calgary, Alberta, Canada.
Abstract
BACKGROUND AND OBJECTIVE: In vitro evaluation of the capsular tension ring for managing zonular dialysis in cataract surgery. MATERIALS AND METHODS: Pig and cadaver eye models were used in this study. Lens material was removed with phacoemulsification, then the zonules were cut in one quadrant of the meridian to induce capsular bag decentration. Posterior chamber intraocular lenses (PC IOLs) were implanted into the bag with or without the tension rings. The IOL and the tension ring positions were viewed using the Miyaki technique. PC IOLs were also implanted into isolated capsular bags with or without tension rings, and bag configuration was examined. RESULTS: The IOL decentration was observed when the IOLs were implanted into the eyes without zonular support in one quadrant of the meridian. No IOL decentration was observed when the tension ring and the IOL were implanted together. When only the IOLs were inserted into the isolated bags they became oval, whereas the circular bags were preserved when both the IOL and the tension ring were placed in-the-bag. CONCLUSION: The authors' in vitro model demonstrated that the capsular tension ring maintained the circular contour of the capsular bag and IOL centration in the eyes with broken zonules. The results suggest that capsular tension rings may provide an alternative means to manage zonular dialysis during phacoemulsification and PC IOL implantation.
BACKGROUND AND OBJECTIVE: In vitro evaluation of the capsular tension ring for managing zonular dialysis in cataract surgery. MATERIALS AND METHODS:Pig and cadaver eye models were used in this study. Lens material was removed with phacoemulsification, then the zonules were cut in one quadrant of the meridian to induce capsular bag decentration. Posterior chamber intraocular lenses (PC IOLs) were implanted into the bag with or without the tension rings. The IOL and the tension ring positions were viewed using the Miyaki technique. PC IOLs were also implanted into isolated capsular bags with or without tension rings, and bag configuration was examined. RESULTS: The IOL decentration was observed when the IOLs were implanted into the eyes without zonular support in one quadrant of the meridian. No IOL decentration was observed when the tension ring and the IOL were implanted together. When only the IOLs were inserted into the isolated bags they became oval, whereas the circular bags were preserved when both the IOL and the tension ring were placed in-the-bag. CONCLUSION: The authors' in vitro model demonstrated that the capsular tension ring maintained the circular contour of the capsular bag and IOL centration in the eyes with broken zonules. The results suggest that capsular tension rings may provide an alternative means to manage zonular dialysis during phacoemulsification and PC IOL implantation.