Sector retinitis pigmentosa

Posterior Polar Annular Choroidal Dystrophy: Genetic Insights and Differential Diagnosis in Inherited Retinal Diseases

“…Such cases often exhibit a diminished maximum ERG response amplitude, reflecting the localized nature of the disorder. These ERG alterations can be similar to those recorded in PPACD patients [1,3,5,6,55].…”

“…RP is responsible for about half of these cases. This condition is characterized by heterogeneous clinical features, including variability in the age of onset, progression speed, the involvement ratio of rod-to-cone photoreceptors, and the extent of RPE involvement [19,54,55].…”

“…Sector RP is characterized by symmetrical retinal degeneration confined to a single quadrant or retinal hemifield. Sector RP accounts for approximately 2% of all RP subtypes, with a steady or slow progression compared to the progression of classic RP [55,59]. As mentioned above, distinctive clinical features include optic disc pallor, bone-spicule pigmentation, and attenuation of retinal vessels, which have not yet been described in PPACD.…”

“…In SD-OCT of sector RP, a correlation between the external limiting membrane (ELM) and ellipsoid zone (EZ) integrity and the hyper-autofluorescent bands identified on FAF has been described [19,54,59]. In contrast, areas with retinal thinning, particularly where the OS of the photoreceptors and the outer nuclear layer are no longer present, are typically associated with decreased autofluorescence signals [55]. In cases of sector RP, SDOCT typically reveals initial pathological changes characterized by the disruption of the interdigitation zone, progressing to the EZ band, and ultimately affecting the ELM [54].…”