This paper examines the process of developing key performance indicators (KPIs) for evaluating the use of high definition video (HD) to video (V2V) communication for tele-monitoring patients in a healthcare setting. The research is performed in the context of the European Commission funded LiveCity project and uses as a case study the monitoring of glaucoma patients using V2V technology. Initially, a set of KPIs are defined for V2V use in eHealth services based on literature and secondary research and these KPIs are then refined based on interviews with medical staff involved in the treatment of glaucoma patients. The obtained KPIs are used to analyse the potential of using V2V services in the context of tele-monitoring glaucoma patients.