Choriocapillaris flow loss in center-involving retinitis pigmentosa: a quantitative optical coherence tomography angiography study using a novel classification system

• Published in: Graefe's archive for clinical and experimental ophthalmology Vol. 259; no. 11; pp. 3235 - 3242
• Main Authors: Ong, Sally S., Liu, T. Y. Alvin, Li, Ximin, Singh, Mandeep S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2021; Springer Nature B.V
• Subjects: Angiography; Choroid; Clinical trials; Eye; Fluorescein Angiography; Humans; Medical imaging; Medicine; Medicine & Public Health; Neuroprotection; Ophthalmology; Photoreceptors; Retina; Retinal Disorders; Retinal Vessels - diagnostic imaging; Retinitis; Retinitis pigmentosa; Retinitis Pigmentosa - diagnosis; Tomography; Tomography, Optical Coherence; Visual Acuity; Fovea; Inherited retinal diseases; Vessel density; Visual acuity; Vascular insufficiency; Stem cell therapy; Gene therapy; Imaging biomarkers; Photoreceptor cells
• ISSN: 0721-832X; 1435-702X; 1435-702X
• DOI: 10.1007/s00417-021-05223-y

Purpose Choriocapillaris insufficiency may play a role in centripetal retinitis pigmentosa (RP) progression involving the fovea. However, the relationship between choriocapillaris integrity and foveal damage in RP is unclear. We examined the relationship between choriocapillaris flow and the presence of foveal photoreceptor involvement in RP. Methods We categorized the severity of central involvement in RP by the occurrence of foveal ellipsoid zone (EZ) disruption: present (severe RP) or absent (mild RP). Using optical coherence tomography angiography (OCTA, AngioVue, Optovue) in cases and unaffected age-matched controls, we compared vessel density (VD) between the groups using the generalized linear mixed model, controlling for age, gender, and scan quality. Results Fifty-seven eyes (20 severe RP, 18 mild RP, and 19 controls) were included. Foveal and parafoveal mean outer retinal thickness (µm) were lower in severe RP (fovea: 101.3 ± 14.5; parafovea: 68.4 ± 11.7) than controls (fovea: 161.2 ± 8.9; parafovea: 142.1 ± 11.8; p  ≤ 0.001) and mild RP (fovea: 162.0 ± 14.7; parafovea: 116.8 ± 29.4; p  ≤ 0.0001). Foveal choriocapillaris VD (%) was lower in severe RP (56.7 ± 6.8) than controls (69.9 ± 4.6; p  = 0.008) and mild RP (65.3 ± 5.3; p  = 0.01). The parafoveal choriocapillaris VD was lower in severe RP than controls (64.4 ± 5.9 vs. 68.3 ± 4.1; p  = 0.04) but no different than in mild RP ( p  = 0.4). Conclusion Choriocapillaris flow loss was associated with fovea-involving photoreceptor damage in RP. Further research is warranted to validate this putative association and clarify causation. Choriocapillaris imaging using OCTA may provide information to supplement structural OCT findings when evaluating subjects with RP in neuroprotective or regenerative clinical trials.