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Photodynamic therapy
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
Darius M Moshfeghi, Gholam A Peyman
Flower55,56 has suggested that the major mechanism of PDT does not involve vascular occlusion, but rather is a sequelae of interruption of Sattler-layer blood vessel flow that feeds the choroidal neovascular membrane. Evidence to support this has been demonstrated by angiographic studies of normal and diseased maculas.57,58 Michels and Schmidt-Erfurth58 reported on the vascular remodeling following verteporfin therapy – they noted early leakage from the CNV and adjacent normal choroid, with occlusion delayed until 1 day and up to 1 week for these structures, respectively. This phenomenon of sequential closing of blood flow with subsequent reperfusion might explain the presence of the hypofluorescent spot seen after PDT, and also account for the high rate of recurrence of leakage seen with this therapy.57,58
Tamoxifen related chorioretinal structural changes
Published in Cutaneous and Ocular Toxicology, 2023
İnci Elif Erbahçeci Timur, Vehbi Açıkgöz, Nagihan Uğurlu, Bülent Yalçın, Mehmet Ali Nahit Şendur, Mutlu Hızal, Halil Kara
Although tamoxifen-related retinal toxicity is rare, central serous chorioretinopathy (CSCR) [9], pacyhchoroid pigment epitheliopathy (PPE) [10,11], and alterations in choroidal thickness [12] were recently reported as tamoxifen-related impairments. PPE and CSCR are pachychoroid spectrum disorders, which have been defined in 2013 as subfoveal choroidal thickness of 300 μm or more [13]. The choroid has the highest amount of vascular tissue of the human body and supplies the posterior segment of the eye, which consists of choriocapillaris, the outer layer with large blood vessels known as Haller’s layer and the inner layer with small and medium vessels known as Sattler’s layer. Measuring choroidal thickness using enhanced depth imaging (EDI) with spectral domain optical coherence tomography (SD-OCT), identifying the vascular layer and stroma of the choroid by the binarisation method is used to determine the pathophysiology of retinochoroidal conditions.
Three-Dimensional Choroidal Vascularity Index in High Myopia Using Swept-Source Optical Coherence Tomography
Published in Current Eye Research, 2022
Lu Liu, Chengcheng Zhu, Ying Yuan, Xiaojun Hu, Chaoyue Chen, Hong Zhu, Bilian Ke
The choroid, a highly vascularized layer located between the retina and the sclera is uniquely situated to supply nutrients to retinal pigment epithelial (RPE) cells and the outer retina11 but also relay retina-derived signals to the sclera to regulate ocular growth.12 It is composed of three vascular layers: the choriocapillaris; the medium choroidal vessels (Sattler’s layer); and the large choroidal vessels (Haller’s layer). Optical coherence tomography (OCT) has allowed more precise non-invasive quantitative assessment of the choroid. In recent years, clinical studies using OCT have demonstrated choroidal thinning with the development of myopia, and a negative correlation between choroidal thickness and axial length, suggesting a close association between choroidal thickness changes and ocular elongation.3,4,13–15 Given the fact that the choroid is primarily a vascular structure, changes in choroidal thickness may be attributable to changes in choroidal vasculature, thus leading to the progression of myopia.16
Retinal Microcirculation Defects on OCTA Correlate with Active Inflammation and Vision in Vogt–Koyanagi–Harada Disease
Published in Ocular Immunology and Inflammation, 2021
Anyi Liang, Chan Zhao, Shanshan Jia, Fei Gao, Xiaoxu Han, Minghang Pei, Yi Qu, Junyan Xiao, Meifen Zhang
However, only a few studies have evaluated OCTA manifestations of VKH patients.8–12 Aggarwal K and colleagues were the first to report OCTA findings of VKH, who discovered choriocapillary flow voids indicating choroidal hypoperfusion.8 Flow void was also found to be useful in follow-up and distinguishing VKH from CSC.9 Several case reports also identified hypoperfusions in retina, choriocapillaris, and Sattler’s layer.10,12 While previous studies revealed the value of OCTA in observing perfusion abnormalities in VKH, most of them are qualitative descriptions of the acute stage with relatively small number of cases. In this study, we aimed to summarize OCTA features from a large cohort of VKH patients at various disease stages and to explore the potential clinical values of quantitative OCTA measurements in the diagnosis, follow-up, and outcome prediction in VKH patients.