A method of processing C-scan data comprising a sequence of B-scans (210, 220) of an imaging target, which has been acquired by an optical coherence tomography, OCT, imaging system, to generate correction data for compensating for axial displacements (d) between B-scans (210, 220) in the sequence of B-scans (210, 220) caused by a relative motion of the OCT imaging system and the imaging target that varies a distance therebetween during acquisition of the B-scans (210, 220) by the OCT imaging system, and to further generate a reliability indicator which indicates a reliability of the generated correction data, the method, when executed by a processor, comprising the steps of: generating the correction data by determining, for each pair of adjacent B-scans (210, 220) of a plurality of pairs of adjacent B-scans (210, 220) in the sequence, a respective indicator of an axial shift between respective representations of a common ocular feature in the adjacent B-scans (210, 220); and generating the reliability indicator by: calculating, using pairs of B-scans (210, 220) in the sequence of B-scans (210, 220), respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans (210, 220) were acquired; determining if at least a predetermined number of the calculated values of the metric exceed a threshold value; in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting (S40A) the reliability indicator to indicate that the correction data is unreliable; and in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting (S40B) the reliability indicator to indicate that the correction data is reliable. generating the correction data by determining, for each pair of adjacent B-scans (210, 220) of a plurality of pairs of adjacent B-scans (210, 220) in the sequence, a respective indicator of an axial shift between respective representations of a common ocular feature in the adjacent B-scans (210, 220); and generating the reliability indicator by: calculating, using pairs of B-scans (210, 220) in the sequence of B-scans (210, 220), respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans (210, 220) were acquired; determining if at least a predetermined number of the calculated values of the metric exceed a threshold value; in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting (S40A) the reliability indicator to indicate that the correction data is unreliable; and in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting (S40B) the reliability indicator to indicate that the correction data is reliable. calculating, using pairs of B-scans (210, 220) in the sequence of B-scans (210, 220), respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans (210, 220) were acquired; determining if at least a predetermined number of the calculated values of the metric exceed a threshold value; in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting (S40A) the reliability indicator to indicate that the correction data is unreliable; and in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting (S40B) the reliability indicator to indicate that the correction data is reliable.