A method for generating an augmented reality image for supporting the adjustment of the position of a surgical instrument during sinus surgery comprising the steps of: selecting at least one of sinus cells, cavities and orifices of the sinus in a pre-operative image by marking them with at least one geometric primitive or tube shaped object； using real-time intra-operative imaging for displaying the operating field； determining the relative positions at least between the real-time imaging of the patient and the pre-operative image data； computing a virtual image corresponding to a real-time image comprising at least one marked geometric primitive or tube shaped object based on the determined relative positions； combining the virtual image and the real-time intraoperative image for visualization in an augmented reality image.
