الفهرس 
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Abstract
Retinitis pigmentosa (RP) is a group of hereditary retinal diseases that result in progressive loss of rod and cone photoreceptors. It occurs in approximately one in 4000 individuals, with a worldwide prevalence of 1.5 million affected individuals. The inheritance of RP is variable, with autosomal dominant, autosomal recessive, X-linked and sporadic cases. There is variable clinical presentation with a wide range of severity, age of onset, progression and other phenotypic features.
Common clinical features of RP include night blindness, progressive loss of peripheral visual field with eventual loss of central vision, and characteristic retinal pigmentary changes that have a bone spicule-like appearance. Other findings include depigmentation of the retinal pigment epithelium (RPE), waxy pallor of the optic nerve, loss of photoreceptors and attenuated retinal vasculature. Electroretinograms are often reduced in amplitude in patients with advanced RP.
Clinically, attenuation of retinal vessels is a common finding in RP. Sclerosis and atrophy of the choriocapillaris has also been described in previous studies. Moreover, fluorescein angiography demonstrates choroidal vessel pathology in early and late stages of RP. The significance of these ocular blood flow alterations in the overall pathogenesis of RP remains unclear.
Nowadays, Imaging of the choroid with optical coherence tomography (OCT) has been greatly facilitated by swept source OCT (SS-OCT) allowing better visualization of both retinal and choroidal anatomy so we present a prospective study of subfoveal choroidal thickness measured by swept source and its correlation with visual acuity in one hundred eyes of 55 patients.
We found that mean of outer retinal layer thickness (ONL) was significantly higher in control group (105.3Um) than RP group (89.0), and significantly correlated with BCVA in RP group, we also found that significant thining of mean subfoveal choroidal thickness (SFCT) in RP group (288.4 Um versus control group 333.7Um), and also has a significant correlation with visual acuity.
As regard to IS/OS integrity, it was significantly correlated with BCVA and mean BCVA (LogMAR) was significantly better in intact IS/OS than disrupted IS/OS, that means that IS/OS line might be an important parameter that can be used to monitor RP patients.
Conclusion:
Finally we conclude that visual prognosis of RP patients could be detect and explained by SS-OCT. The outer retinal layer thickness, SFCT and integrity og IS/OS are important visual parameter can be used to monitor RP patients.
We recommend to do, SS-OCT for RP cases to detect any foveal abnormalities could explain poor vision.