Author: Leonie Keidel
Co-authors: Benedikt Schworm, Julian Langer, Nikolaus Luft, Tina Herold, Felix Hagenau, Siegfried Priglinger, Jakob Siedlecki
Abstract
Purpose. The exact pathophysiology of pachychoroid has yet to be fully elucidated. The aim of this study is to answer the question of whether scleropathy is present as an ocular risk factor for the development of central serous chorioretinopathy (CCS) and pachychoroid neovascularisation (PNV).Setting/Venue. Single center (University Eye Hospital, Ludwig-Maximilian University Munich, Germany), randomized, prospective case-control study between December 2020 and January 2021.
Methods. Patients with CCS or PNV were recruited from the outpatient clinic. A random sample of normal control subjects was recruited and matched by age and refraction. In every patient a complete ophthalmologic examination was performed, as well as Swept Source OCT using an anterior segment module (Dri OCT Triton, Topcon, Tokyo Japan) and posterior segment enhanced depth spectral domain optical coherence tomography (EDI SD-OCT; Spectralis; Heidelberg Engineering GmbH, Heidelberg, Germany). The anterior scleral thickness (AST) was measured underneath the insertion site of the lateral rectus muscle using Swept Source OCT. Subfoveal choroidal thickness (SFCT) was assessed on standard macular volume scans (EDI SD-OCT) by manual measurements of the distance between the Bruch’s membrane and the choroidal-scleral interface below the foveola. AST and SFCT were then compared to an age and -refraction-matched control group.
Results. In total, 46 eyes of 46 patients were included in this study, with 23 eyes in the CCS/PNV and 23 eyes in the control group. There was no difference in mean age (51.5 ± 8.0 (36 to 65) vs. 47.0 ± 12.9 (30 to 83) years; p=0.122) or spherical equivalent (0.60 ± 2.23 (-5.5 to 4.6) vs. -0,93 ± 2.45 (-4.9 to 5.8); p=0.441). A significantly higher AST was found in the CCS (403.5 ± 68.6 (278 to 619) µm) as compared to the control group (362.5 ± 62.6 (218 to 498); p=0.028). The CCS/PNV group showed a higher SFCT (392.8 ± 92.8 (191 - 523) µm), as compared to the control group (362.5 ± 62.6 (218 – 493) µm, p=0,06).
Conclusions. Compared to age- and refraction-matched controls, patients with CCS and PNV show a significantly thicker anterior sclera. Our data indicate that a significantly thickened sclera may represent an ocular outflow resistance for the vortex veins in eyes with CCS and PNV and secondarily cause a chronic overload of the venous system, congruent with the pathophysiology of UES. A chronic backflow into the venous system of the choroid may, on the one hand, cause anterograde filling delay of the choriocapillaris with formation of ischemic areas and, on the other hand, may result in thickening of the Haller layer. These two factors combined may ultimately lead to the development of the typical pachychoroidal features.
Financial disclosures: No author reports any financial interest relevant to this study.
Leonie Keidel received previous speaker fees and/or travel expenses from Recordati Rare Diseases Inc. and Roche Diagnostics GmbH.
Benedikt Schworm received previous speaker fees and travel expenses from Novartis Pharma GmbH and Topcon Corporation.
Julian Langer has no financial disclosures to declare.
Nikolaus Luft received income from honoraria as a lecturer from Alcon Laboratories Inc., NIDEK Co. Ltd and CenterVue SpA.
Tina Herold has no financial disclosures to declare.
Felix Hagenau received previous speaker fees and travel expenses from Allergan GmbH and Novartis Pharma GmbH. Siegfried Priglinger received previous speaker fees and/or travel expenses from Novartis Pharma GmbH, Oertli AG, Bayer AG, Alcon Pharma GmbH and Pharm-Allergan GmbH.
Jakob Siedlecki received previous speaker honoraria, personal consultations honoraria and travel expenses from Novartis Pharma GmbH, Bayer AG, Roche AG, Carl Zeiss Meditec AG, Oculentis OSD Medical GmbH and Allergan GmbH.