Which of the following is seen retinitis pigmentosa?
High-Yield Explanation
Retinitis pigmentosaApoptosis of rodsAR - most common RISK FACTOR- Consanguineous marriagesC/F- Nyctalopia- Ring scotoma +nt- Progress to tubular vision (constriction of visual fields) O/E- TRIAD- Pale waxy disc- Aeriolar attenuation- BONE SPICLUE PIGMENTATION (characteristic) - Gold standard for Dx - ERG- Measures the potential difference ofNeuro sensory layerNORMAL ERG- Negative 'a' -wave- Positive 'b' -wave- Small 'c' -wave (sometimes)- a-wave - measures the potential difference of photoreceptors- b-wave - measures the potential differenceOf Muller's cells (neuroglia) & bipolarCells (neuronal cells) In Retinitis Pigmentosa- ERG becomes FLAT