The retinal image is a trusted modality in biomedical image-based diagnosis of many ophthalmologic
and cardiovascular diseases. Periodic examination of the retina can help in spotting these abnormalities in the early
stage. However, to deal with today's large population, computerized retinal image analysis is preferred over manual
inspection. The precise extraction of the retinal vessel is the first and decisive step for clinical applications. Every year,
many more articles are added to the literature that describe new algorithms for the problem at hand. The majority of the
review article is restricted to a fairly small number of approaches, assessment indices, and databases. In this context, a
comprehensive review of different vessel extraction methods is inevitable. It includes the development of a first-hand
classification of these methods. A bibliometric analysis of these articles is also presented. The benefits and drawbacks of
the most commonly used techniques are summarized. The primary challenges, as well as the scope of possible changes,
are discussed. In order to make a fair comparison, numerous assessment indices are considered. The findings of this
survey could provide a new path for researchers for further work in this domain.