The retina is a thin layer of nerve tissue which lines the inside wall of the eye. Much like the film in a camera, the retina senses light which is focused by the eye’s cornea and lens, and converts the optical image to electrical and chemical signals which travel through the optic nerve to the vision center in the brain.
The central part of the retina which is most useful for detailed vision such as reading is called the macula. The retina is only about a quarter of a millimeter thick and may be examined in the office using a slit-lamp microscope after the eye is dilated with eyedrops. High-tech, non-invasive retinal imaging techniques such as optical coherence tomography can show the different cell layers of the retina and are important in the diagnosis and management of retinal diseases.
Common diseases which affect the retina include macular degeneration, diabetic retinopathy, retinal vein occlusion, epiretinal membrane, and retinal detachment. Retinal disease may cause blurry vision, distorted vision, or darkness in one part of the vision. Retinal disease may be treated with intra-ocular injections of medication, laser therapy, or surgery.
An ophthalmologist’s view of the surface of the retina using a slit-lamp microscope (after the eyes are dilated)