Retinal disorders of metabolic origin - common roots, different manifestations and endogenous protective mechanisms

Abstract

The visual world is the most important environmental information source for humans. Approximately 70% of the sensory cues reach us through vision. None of the other sensory signals is processed by as many cortical areas as forms and colors. The first steps of visual processing happen in a thin sheath of neural tissue at the back of the eye, called retina. Photoreceptors transduce light into neural signals and these are further shaped by the retinal circuitry. There is only one source of visual signals to the brain: the retina. Therefore any damage to the retinal tissue may immediately result in vision loss and sometimes blindness. Sight-threatening neurodegenerative diseases of the retina may affect as many as 5-7% of the human population. They can be either of genetic origin, e.g. retinitis pigmentosa and microphthalmia [1] or metabolic disorders including glaucoma, ischemia, macular degeneration and diabetic retinopathy [2]. Age is also listed among the major risk factors affecting proper retinal function.