TY  - BOOK
AU  - Kirollos Joseph Guirguis Escander,
AU  - Sherif Aly Gamal El-Din
AU  - Ahmed Abdallah Mohalhal 
AU  - Alaa El-Din Abdelsalam Fayed
TI  - Peripapillary vascular tortuosity index as a sign of stasis precipitating retinal vein occlusion in primary glaucomas
U1  - 617.73 
PY  - 2024///
KW  - Visual and retinal nerve diseases
KW  - qrmak
KW  - Retinal vein occlusion
KW  - vascular tortuosity index
KW  - primary glaucomas
KW  - peripapillary
KW  - OCT-A
KW  - superficial capillary plexus
KW  - deep capillary plexus
N1  - Thesis (Ph.D)-Cairo University, 2024; Bibliography: pages 78-93; Issues also as CD
N2  - Background: Retinal vein occlusion (RVO) is one of the most common retinal vascular disorders. It is associated with the occurrence of glaucoma as one of its main risk factors. The exact pathogenesis is unknown, however several theories state that the vascular stasis precipitating venous occlusion may result from external compression, vascular obstruction, or vascular wall pathology.

Methods: This study was an observational, cross-sectional, case control study aiming at the evaluation of retinal peripapillary vascular tortuosity index (VTI) using OCT-A images as a sign of vascular stasis. 45 eyes were equally distributed among three study groups; healthy controls, glaucomatous eyes with no RVO and glaucomatous eyes with unilateral RVO. We also studied their OCT-A scans to obtain the vessel density of the peripapillary and macular capillary plexuses for evidence of capillary non-perfusion.

Results: Our study revealed a statistically significant difference in the VTI among the three groups (p-value < 0.001); the highest VTI was in the glaucoma + RVO group (1.13 ± 0.02, 1.16 ± 0.02) followed by the glaucoma with no RVO group (1.06 ± 0.01, 1.07 ± 0.01) and at last the healthy control group (1.04 ± 0.01,
1.05 ± 0.01).The vessel density was significantly less in the macular superficial capillary plexuses in glaucomatous compared to non-glaucomatous eyes, but deep capillary plexuses showed no statistically significant difference.
Conclusion: Primary glaucomas contribute to higher levels of peripapillary vascular stasis manifested by increased vascular tortuosity. This may precipitate retinal vein occlusion in these eyes even in the absence of other classic cardiovascular risk factors
ER  -