EC Ophthalmology

Many patients have difficulty in seeing in low light, which in medical terminology is called as nyctalopia, which may be due to various reasons such as pathological myopia, xerophthalmia (Vitamin A deficiency), advanced cases of open angle glaucoma, peripheral cortical cataract and retinitis pigmentosa. Night blindness is one of the earliest symptom of retinitis pigmentosa.

Retinitis pigmentosa is a type of retinal dystrophy, which predominantly affects rod photoreceptor cells of retina, with subsequent degeneration of cones. Rod photoreceptors are responsible for vision in low light levels; thus night blindness is one of the earliest feature of Retinitis pigmentosa. Night blindness may be present several years before pigment is visible in retina. The visual fields show concentric contraction, especially marked if the illumination is reduced. Fundus examination of a case of retinitis pigmentosa shows arteriolar attenuation, waxy pale optic disc, bony spicule pigmentation, shining reflex at macula, known as tapetal reflex.