Agreement Of Retinal Vessel Diameter Measurement And Its Application In RVO Evaluation

PART ⅠAGREEMENT BETWEEN TWO OCT SCAN MODES IN MEASURING RETINAL VESSEL DIAMETER Objective: To compare the agreement of two built-in scanning modes(circle scan and raster scan)in measuring retinal vessel diameter by using optical coherence tomography(OCT).Methods: A total of 79 healthy volunteers who underwent physical examination in our department from December 2018 to April 2019 were collected and analyzed according to the inclusion and exclusion criteria,including 40 males and 39 females;39 right eyes and 40 left eyes.OCT was used to obtain images centered on the optic disc to measure the diameter of the blood vessels and analyze the consistency of the two modes.Results: The venous and arterial diameters of the third line scan of raster scan and the circular scan were: veins(the third line: 164.87 ± 17.80μm vs.circular scans: 163.00 ± 17.50μm,P=0.07);arteries(the third line:132.34±14.13μm vs.131.22 ± 15.01μm,P=0.234).The third line scan and circular scan had good consistency in measuring vessel diameter(venous:intraclass correlation coefficient(ICC)= 0.87,P<0.001;arterial: ICC = 0.84,P<0.001).Conclusion: In measuring retinal vessel diameter,the third line scan and the circular scan have good agreement.PART Ⅱ CHANGES OF VESSEL DIAMETER IN BRANCH RETINAL VEIN OCCLUSION Objective: Fundus fluorescein angiography(FFA)of patients with branch retinal vein occlusion(BRVO)was used to analyze the difference between the diameter of the blood vessel in the affected quadrant and matching quadrant on the healthy side of the blood vessel trunk,and the vessel diameter before and after the occlusion point.The relationship between vessel diameter and retinal non-perfusion was also analyzed.Methods: Patients diagnosed with BRVO in the ophthalmology department of the Sixth People’s Hospital Affiliated to Shanghai Jiaotong University from January 2015 to December 2019 were selected according to the inclusion criteria.Vessel diameter was measured by using FFA images,and non-parametric tests were used to analyze the differences in vessel diameters between the affected and healthy sides,before and after the occlusion point,and between ischemic and non-ischemic BRVO.Receiver operating characteristic(ROC)was used to assess the relationship between vessel diameter and retinal non-perfusion.Results: Arterial trunk diameter:(affected quadrant: 104.57 ± 17.18μm vs.unaffected quadrant: 110.76±16.23μm,P < 0.001).Venous trunk diameter:(affected quadrant: 140.68±25.74μm VS.unaffected quadrant:156.67±15.89μm,P<0.001).In ischemic BRVO,the diameter of vein before the occlusion point was 77.82 ± 31.84μm,and the diameter of the arterial trunk of the affected quadrant was 101.05 ± 19.34μm.In non-ischemic BRVO,the diameter of vein before the occlusion point was 97.33 ±24.98μmμm(P=0.043),and the diameter of the arterial trunk of the affected quadrant was 108.96 ± 13.06μm(P=0.041).The area under curve(AUC)of drainage index(vein diameter before occlusion point / vein diameter after occlusion point)had the highest area under curve(AUC)of 0.815.Conclusion: Compared with vessels of matching quadrant on the healthy side,the arterial and venous trunks of the affected quadrant had narrowed blood vessel diameters,and the diameter of the arterial trunk of the affected quadrant and the degree of narrowing of the veins before the occlusion point,and smaller drainage index were related to retinal ischemia.