Ocular pulse amplitude is reduced in patients with advanced retinitis pigmentosa

Background/aims-The choroid, a low resistance vascular structure carrying 8 5% of the ocular blood flow, provides nourishment to and removal of potenti al toxic waste products from the adjacent non-vascularised outer layers of the retina, macula, and optic disc regions. Choroidal perfusion may be redu ced in retinitis pigmentosa (RP) and might contribute to retinal pigment ep ithelium (RPE) degeneration. The aim of this study was to determine whether choroidal perfusion is reduced in RP and whether this is correlated with t he stage of disease. Methods-Ocular pulse amplitude (OPA) evaluated with the ocular blood flow ( OBF) system, applanation intraocular pressure (IOP), visual fields, blood p ressure (BP), and heart rate (HR) were measured in 75 RP patients having st age RP-I (stage I: visual field size: 7.85-14.67 cm(2); n = 22), stage RP-I I (stage II: visual field size: 2.83-7.84 cm(2); n = 29), or stage RP-III ( stage III: visual field size: 0.52-2.82 cm(2); n = 24) were compared with m atched healthy controls and each other. Results-Neither IOP nor systemic perfusion parameters were significantly (p >0.1) altered, but OPA (mm Hg) in RP patients beginning with stage RP-II ( 1.6 (0.1), 27.3%, p<0.0001), and RP-III (1.2 (0.1), 45.5%, p<0.0001) was si gnificantly reduced when compared with matched subgroups from a pool of hea lthy controls (2.2 (0.1), n = 94). Conclusions-OPA can be used neither for early clinical detection of RP nor to follow the natural course of the disease. However, our data show that in advanced stages of RP not only the retina but also the choroidal circulati on is affected.