Baseline characteristics of eyes according to retinal oxygen saturation
| Groups according to percentiles of arteriolar oxygen saturation | P value | ||
| Group A | Group B | ||
| Arteriolar oxygen saturation (%) | 91.1 (89.8–92.3) | 100.1 (96.6–103.5) | |
| n | 17 | 18 | |
| Age (years) | 64.0 (55.5–72.5) | 58.8 (53.5–64.0) | 0.25 |
| Sex (% women) | 17.7 | 16.7 | 0.94 |
| Duration of diabetes (years) | 12.9 (5.9–19.9) | 9.7 (3.2–16.2) | 0.48 |
| Haemoglobin A1c (mmol/mol) | 64.2 (52.6–75.9) | 62.6 (51.1–74.2) | 0.84 |
| Body mass index (kg/m2) | 28.0 (25.3–30.7) | 28.9 (25.3–32.4) | 0.63 |
| Mean arterial pressure (mm Hg) | 101.0 (94.6–107.4) | 102.5 (95.5–109.5) | 0.68 |
| Smoking (pack years) | 12.2 (2.2–22.1) | 14.2 (4.2–24.3) | 0.73 |
| Best corrected visual acuity (ETDRS letters) | 74.7 (72.5–76.8) | 69.5 (64.0–75.0) | 0.08 |
| Central retinal thickness (µm) | 367.1 (334.4–399.8) | 410.9 (349.6–472.2) | 0.20 |
| Groups according to percentiles of venular oxygen saturation | |||
| Venular oxygen saturation (%) | 56.4 (53.8–59.0) | 69.3 (66.6–71.9) | |
| n | 18 | 17 | |
| Age (years) | 60.4 (55.0–65.8) | 62.3 (52.8–71.8) | 0.72 |
| Sex (% women) | 16.7 | 17.7 | 0.94 |
| Duration of diabetes (years) | 14.4 (7.6–21.1) | 7.9 (1.2–14.6) | 0.18 |
| Haemoglobin A1c (mmol/mol) | 66.0 (56.4–75.6) | 60.6 (46.3–74.8) | 0.52 |
| Body mass index (kg/m2) | 28.1 (25.3–30.8) | 28.8 (25.0–32.6) | 0.72 |
| Mean arterial pressure (mm Hg) | 101.6 (94.6–108.5) | 102.0 (95.2–108.8) | 0.91 |
| Smoking (pack years) | 17.6 (5.3–29.9) | 8.6 (0.33–16.8) | 0.22 |
| Best corrected visual acuity (ETDRS letters) | 73.1 (69.8–76.3) | 70.9 (65.7–76.1) | 0.46 |
| Central retinal thickness (µm) | 397.8 (339.7–456.0) | 380.9 (346.8–414.9) | 0.61 |
Continuous data presented as mean with (95% CIs) and categorical data as per cent. Differences between groups of eyes with the lowest and highest retinal arteriolar oxygen saturations, respectively, were tested employing cluster robust standard errors for linear regression models.
ETDRS, Early Treatment Diabetic Retinopathy Study.