Comparison of 3 Designs of PCO-Preventing Rings
To investigate three designs of open capsule ring (OCR) with different size and density of side wall apertures on PCO and Sommering's ring formation.
Twenty-four NZW rabbits' eyes were divided to 3 groups. 3 different OCRs were implanted into the capsular bag after crystalline lens evacuation. Group A (n=8): 190 degrees of large side wall apertures, group B (n=9): 90 degrees of small side wall apertures, and group C (n=7): 175 degrees of small side wall apertures. The same intraocular lens was then implanted into the OCR. A weekly slit lamp exam was performed for the 6 weeks of the study duration. After 6 weeks the rabbits were scarified, the eyes were enucleated and fixated and then evaluated using the Miyake-Apple view and histology.
Similar low PCO levels and Sommering's ring formation were found in all the study groups. Six weeks slit lamp PCO level were: A: 0.4±0.7, B: 0.8±0.8, C: 0.5±0.8; p=0.5. Histology PCO level were: A: 0±0, B: 0.7±0.1, C: 0.4±1.1; p=0.25, Sommering's Ring area(%): A: 29+17, B: 26+12, C: 25+15; p=0.38. Area of Sommering's ring protrusion inside the OCR (%): A: 18+14, B:13+10, C: 16+13, P=0.31.
The three OCR designs showed similar PCO and Sommering's ring prevention. There seems to be a tendency for lower Sommering's ring protrusion inside the OCR in the low density small side wall apertures but the difference was not statistically significant.