Wide-angle viewing system with operating microscope OMS800-OFFISS and 120-diopter convex lens

Background : OMS800-OFFISS was designed for bimanual vitreous surgery. It can be converted into a wide-viewing system by substituting+40 diopter lens by a+120 diopter one and additional use of light pipe. The microscope can be operated independent of the convex lens. Purpose: To evaluate the maximum range of intraoperative observation with this system. Cases: A total of 1,056 eyes were operated using this system during the past 12 months. The series comprised 49 phakic eyes, 174 pseudophakic eyes, and 833 aphakic eyes. Results: Vitreous surgery could be performed without problem in these 1,056 eyes. In consecutive 110 eyes, ora serrata could be observed in 103 eyes (94%) without indenting the sclera. The vitreous base could be observed in the other 7 eyes. Conclusion: The present system enables observation of the fundus in wide angle, operation of microscope independent of convex lens, and is useful in observing the fundus during vitreous surgery.