A review of the human retina with emphasis on nerve fibre layer and macula thicknesses

The retina is the innermost neural layer of the eye, and is the site of transformation of light energy into a neural signal. Knowledge and assessment of the human retinal structural parameters are important for the appropriate diagnosis and management of various ocular diseases. For instance, potentially blinding eye diseases, such as glaucoma and age-related macular degeneration, cause structural changes in the retina. Clinical evidence with ocular coherence tomography also suggests that eyes with glaucoma lose retinal nerve fibre layer and ganglion cells axons before loss of visual function. These losses appear as a visible change in the optic nerve head and can be seen before visual field abnormalities are noticed by the patient. This review discusses certain aspects (anatomical structures, structural changes with eye diseases, and assessment methods) involving the human retina, their clinical importance, and factors that may influence them. The content of this article will be useful to optometrists and ophthalmologists who assess these parameters in normal patients as well as in those with eye conditions such as glaucoma.