Captions on all figures and tables need to be complete. They should fully explain the illustration, even when taken out of context. Readers are often looking at tables and figures before they begin reading the text of your document or later when they want to quickly remind themselves of your findings. The caption should be detailed enough that the illustration can be understood without referring to the text. In addition, it is important that labelling (axes on graphs, column headings in tables etc) is full and complete. All units of measurement should be given. If abbreviations are used they need to be explained in the caption. All illustrations should be referred to in the body of the text of your document.
Here are two examples of captions taken from recent publications. You should look yourself at the style of caption used in publications you are referring to in your own literature review. Different journals will have different styles but the principles remain the same.
Example 1: Figure from Valletta JJ, Chipperfield AJ, Clough GF, Byrne CD (2014) Daily Energy Expenditure, Cardiorespiratory Fitness and Glycaemic Control in People with Type 1 Diabetes. PLoS ONE 9(5): e97534. doi: 10.1371/journal.pone.0097534 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0097534#pone-0097534-g004
Note that all abbreviations are explained in the caption, as are the meaning of the symbols. The axis used in both graphs spans the same range so the reader can easily compare them. All axes are fully labelled including units. The results are also interpreted for the reader.
Example 2: Figure from Kikawa K, Sakano D, Shiraki N, Tsuyama T, Kume K, et al. (2014) Beneficial Effect of Insulin Treatment on Islet Transplantation Outcomes in Akita Mice. PLoS ONE 9(4): e95451. doi: 10.1371/journal.pone.0095451 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0095451#pone-0095451-g003
Note that in this example the experimental protocol is briefly outlined and conclusions explained for the reader. Some abbreviations are not explained in the caption, and in my opinion it would be better if they were. However these are terms which are no doubt used throughout the paper and with which readers would be familiar.