Choroidal caverns in pachychoroid neovasculopathy

Abstract

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.