The Heidelberg Retina Tomograph (HRT) II is a confocal scanning laser device used to acquire images of the optic nerve head. In this paper the authors report a novel use of this device in the assessment of papilledema in a patient with pilocytic astrocytoma of the pineal region. They also present a new technique to objectively produce 3D data of the optic nerve head. An 11-year-old girl presented with headache and bilateral papilledema; magnetic resonance imaging revealed a lesion in the pineal region. A suboccipital craniectomy was performed, and HRT images were obtained both before (baseline) and after (follow-up) the operation. The authors analyzed the height variation of the retinal surface along the vertical and horizontal cross-lines passing the center of the optic nerve head. The postoperative images, studied on the 2nd day after operation, demonstrated visible reduction of the papilledema. The height variation of the retinal surface along the contour line created by the software demonstrated that elevation of the optic nerve head became depressed due to resolved swelling. The height variation of the retinal surface along vertical and horizontal cross-lines demonstrated significant differences between the elevated preoperative curve and the postoperative curve (p \u3c 0.001), consistent with improvement of her symptoms. Initial data suggest that changes in the optic nerve head topography after surgical decompression can be quantitatively documented by 3D data from the HRT II