The retina is characterized by being a thin layer of nervous tissue located at the back of the eye, and is responsible for transforming light into nerve stimuli, which allows the formation of images in the brain.
There are several congenital and acquired diseases that affect the retina in dogs and cats. However, the most common ones are Progressive Retinal Atrophy (PRA) and Sudden Acquired Retinal Degeneration (SARDS).
Progressive Retinal Atrophy is due to a degeneration of cells in the retina (called photoreceptors). At an early stage, the disease is characterized by loss of night vision. Unfortunately, after a period of one or two years, vision can be lost in its entirety.
Sudden Acquired Retinal Degeneration consists of a set of morphological and permanent changes in several layers of the retina. In clinical terms, pets present sudden blindness and dilated pupils.
The cause of both diseases is currently unknown, and their diagnosis is obtained through a complete ophthalmological examination, including a study of the fundus of the eye. Loss of retinal function can be confirmed by a test designated electroretinography.
Currently, there is no effective treatment for these diseases. However, these are painless, and pets adapt relatively well to the loss of vision, especially with the help of their tutors, as they use their remaining senses to compensate for the lack of vision.
The retina is characterized by being a thin layer of nervous tissue located at the back of the eye, and is responsible for transforming light into nerve stimuli, which allows the formation of images in the brain.
There are several congenital and acquired diseases that affect the retina in dogs and cats. However, the most common ones are Progressive Retinal Atrophy (PRA) and Sudden Acquired Retinal Degeneration (SARDS).
Progressive Retinal Atrophy is due to a hereditary degeneration of the photoreceptors present in this intraocular structure. At an early stage, the disease is characterized by loss of night vision. Unfortunately, after a period of one or two years, vision can be lost in its entirety. Additionally, bilateral cataracts sometimes develop a few years after the onset of clinical signs. Clinical findings on ophthalmoscopy include tapetal hyperreflectivity and retinal vascular attenuation.
Sudden Acquired Retinal Degeneration consists of a set of morphological and permanent changes in several layers of the retina, of unknown cause. Clinically, pets experience blindness over a period of days or 1-2 weeks, and mydriasis. At an early stage, no changes are identifiable on ophthalmoscopy, although these may appear over time. Affected pets are generally healthy, although some present a clinical condition suggestive of hyperadrenocorticism.
The diagnosis of both diseases is obtained through a complete ophthalmological examination, including slit lamp ophthalmoscopy, which allows a morphological study of the retina. The study of retinal function, through electroretinography, and together with the clinical sings, allows us to distinguish between PRA and SARDS. Currently, there is no effective treatment or curative for PRA and SARDS. Oral antioxidants may sometimes be prescribed, which have already demonstrated some beneficial effects in degenerative retinal diseases in humans. However, its effectiveness has not yet been scientifically proven in animals. Nevertheless, these diseases are painless, and pets adapt relatively well to the loss of vision, especially with the help of their tutors, as they use their remaining senses to compensate for the lack of vision.