Optic disc changes of retinitis pigmentosa:

Retinitis pigmentosa (RP) is a type of retinal dystrophy predominantly effecting the rod photo receptor cells of the retina with subsequent degeneration of the cones Sporadic: most common Clinic - investigative features Night blindness May occur before the retinal changes appear. Fundus changes Retinal pigmentary changes occur in the form of perivascular deposition (jet black spots) of bony corpuscle pigments in the equatorial region which later spread both. Anteriorly and posteriorly Retinal aerioles are attenuated Optic disc becomes pale waxy ending in consecutive optic atrophy. Visual field changes Annular of ring scotoma Tubular vision in advanced cases - Electrophysiological changes Appears even before the subjective symptoms and signs Scotopic flash ERG: decrease in amplitude of the 'a' wave EOG is extinguished