Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the
retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to
various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and
vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel
enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments.
This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans.
The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation
shows the proposed filter is better than several known techniques and is comparable to the state of the art when
evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to
demonstrate the effectiveness of the enhancement filter.