Retinitis pigmentosa. Ophthalmoscope view of the retina of the eye, showing retinitis pigmentosa. Here, a pattern of dark spots and star-shaped blotches occurs across the retina. This is due to degeneration of the light-sensitive layer of the eye, leading to loss of vision. The first symptom of retinitis pigmentosa is usually an awareness that vision is poor in low light. Sight testing reveals a ring-shaped area of blindness, that progresses to involve an increasing area of the visual field. The central retina (in the region of the macula) is more resistant & so central vision may be retained, often for many years. Retinitis pigmentosa usually has a genetic basis.