Characteristics and diabetic retinopathy stages of subjects with type 1 diabetes
| Level 1 | Level 2 | Level 3 | |
| Number | 20 | 27 | 12 |
| Age (years) | 22.9 (4.2) | 23.7 (4.5) | 22.1 (4.0) |
| Glucose plasma levels (mg/100 ml) | 121.3 (57.9) | 164.3 (67.0) | 194.8 (84.4) |
| HbA1c (%) | 7.7 (1.1) | 8.5 (1.0) | 10.7 (1.5) |
| Systolic blood pressure (mm Hg) | 127.9 (7.1) | 121.1 (10.5) | 124.8 (8.0) |
| Diastolic blood pressure (mm Hg) | 66.3 (12.1) | 60.6 (10.1) | 60.0 (7.3) |
| Pulse rate (min) | 72.4 (11.4) | 73.4 (11.2) | 74.3 (10.5) |
↵According to Modified Airlie House Classification (level 1: no retinopathy, level 2: microaneurysms (one or more) only, level 3: microaneurysms and one or more of the following: retinal haemorrhages, but total haemorrhages and microaneurysms (H/Ma) less than standard photo No 2; hard exudates (HE) <standard photo No 3; soft exudates (SE) questionably present; intraretinal microvascular abnormalities (IRMA) questionably present, venous beading (VB) questionably present or venous focal narrowing or loops definitely present.