Response of choroidal blood flow to carbogen breathing in smokers and non-smokers

• Published in: British journal of ophthalmology 2004-06, Vol.88 (6), p.776-781
• Main Authors: Wimpissinger, B, Resch, H, Berisha, F, Weigert, G, Schmetterer, L, Polak, K
• Format: Article
• Language: English
• Subjects: Adult; Analysis of Variance; Biological and medical sciences; Blood pressure; carbogen; Carbon Dioxide - administration & dosage; Case-Control Studies; Choroid - blood supply; choroidal blood flow; Cigarettes; Clinical Science - Scientific Reports; DBP; diastolic blood pressure; Disease; Family medical history; FPA; Fundus Oculi; fundus pulsation amplitude; Gases; Humans; Inhalation; Laser-Doppler Flowmetry; Lasers; LDF; Male; mean arterial blood pressure; Medical sciences; Nitric oxide; ONH; Optic Disk - blood supply; Optic Disk - drug effects; Optic nerve; optic nerve head; Oxygen - administration & dosage; pulse rate; RBC; red blood cell; Regional Blood Flow - drug effects; Retina; retinal vessel analyser; Retinal Vessels - anatomy & histology; Retinal Vessels - drug effects; RVA; SBP; Single-Blind Method; Smoking; Smoking - adverse effects; Studies; systolic blood pressure; Tobacco, tobacco smoking; Toxicology; Urine; Vasoconstriction; Veins & arteries
• ISSN: 0007-1161; 1468-2079
• DOI: 10.1136/bjo.2003.031773

Aim: To investigate a potential difference in ocular vascular reactivity during carbogen breathing in optic nerve head, choroid, and retina between healthy smokers and non-smokers. Methods: 25 (13 smokers and 12 non-smokers) healthy male volunteers participated in this observer masked, two cohort study. During inhalation of carbogen (5% CO2 and 95% O2) over 10 minutes measurements were taken using laser Doppler flowmetry to assess submacular choroidal and optic nerve head blood flow, laser interferometry to assess fundus pulsation amplitudes, and retinal vessel analyser (RVA) to assess retinal vessel diameters. Results: At baseline choroidal blood flow was higher (p = 0.018, ANOVA) in smokers than in non-smokers. During administration of carbogen the response in choroidal blood flow was significantly different between the two groups: there was an increase in non-smokers after carbogen breathing (p = 0.048) compared with relatively stable blood flow in smokers (p = 0.049 between groups, ANOVA). A similar response pattern was seen for fundus pulsation amplitude, which increased notably after carbogen breathing in non-smokers but not in smokers (p