A tool was developed that assists surgeons in manipulating surgical instruments more precisely than is possible manually. The tool is a telemanipulator that scales down the surgeon's hand motion and filters tremor in the motion. The signals measured from the surgeon's hand are transformed and used to drive a six-degrees-of-freedom robot to position the surgical instrument mounted on its tip. A pilot study comparing the performance of the telemanipulator system against manual instrument positioning was conducted at the University of Southern California School of Medicine. The results show that a telerobotic tool can improve the performance of a microsurgeon by increasing the precision with which he can position surgical instruments, but this is achieved at the cost of increased time in performing the task. We believe that this technology will extend the capabilities of microsurgeons and allow more surgeons to perform highly skilled procedures currently performed only by the best surgeons. It will also enable performance of new surgical procedures that are beyond the capabilities of even the most skilled surgeons.

Objective: To describe the clinical characteristics and survival experience of a prospectively followed up group of patients with small choroidal melanoma.Methods: The Collaborative Ocular Melanoma Study (COMS) is a set. of clinical trials designed to compare the role of radiotherapy and enucleation in the treatment of medium and large-size choroidal melanoma. From December 1986 to August 1989, patients with small choroidal melanoma, not large enough to be eligible for the COMS clinical trials, were offered participation in a nonrandomized prospective follow-up study. Small choroidal melanomas were defined as 1.0 to 3.0 mm in apical height and al least 5.0 mm in basal diameter. A total of 204 patients were enrolled in the study. Patients were followed up annually through August 1989. Two additional assessments of treatment status and mortality were conducted in 1993-1994 and 1995-1996. The median length of follow-up was 92 months. Eight percent of patients were treated at the time of study enrollment and an additional 33% were treated during follow-up.Results: Twenty-seven patients have died; 6 deaths were reported by the clinical center as due to metastatic melanoma. The Kaplan-Meier estimate of 5-year all-cause mortality was 6.0% (95% confidence interval, 2.7%-9.3%) and 8-year all-cause mortality was 14.9% (95% confidence interval, 9.6%-20.2%).Conclusions: Otherwise healthy patients, average age of GO years, without a previous diagnosis of malignant disease who have small choroidal lesions judged to be melanoma have a low risk of dying within 5 years.