Table 2. Correlation analysis of all parameters within Stargardt disease patients.
| Parameter | STGD1 patients (n = 80), Mean (SD) or n (%) | C3d (mg/l) | C3 (mg/l) | C3d/C3 ratio | |
|---|---|---|---|---|---|
| Cross-sectional parameters related to STGD1 pathology | |||||
| Age at onset in years | 33 (19) | Spearman’s Correlation P value |
-0.127 0.262 |
-0.044 0.700 |
-0.117 0.303 |
| Disease duration in years | 13 (12) | Spearman’s Correlation P value |
-0.061 0.589 |
0.020 0.863 |
-0.030 0.789 |
| VA in decimals, average of both eyes | 0.40 (0.40) | Spearman’s Correlation P value |
-0.130 0.249 |
-0.020 0.858 |
-0.127 0.261 |
| DDAF area in mm2, average of both eyes | 10 (18) | Spearman’s Correlation P value |
-0.009 0.938 |
-0.011 0.929 |
0.019 0.873 |
| Retrospective parameters related to STGD1 progression (available for 50 patients) | |||||
| VA decline in decimals/year, average of both eyes | 0.02 (0.08) | Spearman’s Correlation P value |
0.138 0.311 |
-0.010 0.941 |
0.134 0.324 |
| DDAF growth in mm2/year, average of both eyes | 0.94 (1.53) | Spearman’s Correlation P value |
-0.014 0.926 |
-0.230 0.108 |
0.094 0.517 |
| Demographic and behavioural factors | |||||
| Age in years | 46 (18) | Spearman’s Correlation P value |
-0.168 0.135 |
-0.037 0.744 |
-0.150 0.183 |
| Sex | Males, 36 (45%) Females, 44 (55%) |
Level in males, mean (SD) Level in females, mean (SD) Mean Difference (95% CI) T-test, P value |
3.7 (1.1) 3.7 (1.4) -0.712 (-0.634–0.492) 0.110 |
1025 (112) 1159 (228) -134 (-212 - -56) 0.001 a |
3.6 (1.2) 3.3 (1.2) 0.302 (-0.315–0.920) 0.396 |
| BMI | 25 (4) | Spearman’s Correlation P value |
0.124 0.273 |
0.463 <0.001a |
-0.173 0.124 |
| Smoking 3 categories | Current smokers, 11 (14%) Past smokers, 22 (27%) Non-smokers, 47 (59%) |
Level in current smokers, mean (SD) Level in past smokers, mean (SD) Level in non-smokers, mean (SD) ANOVA, p value |
4.2 (2.0) 3.4 (0.8) 3.7 (1.2) 0.273 |
1122 (232) 1104 (193) 1091 (192) 0.894 |
4.0 (2.6) 3.1 (0.6) 3.5 (1.2) 0.211 |
| Smoking in packyears | 5 (11) | Spearman’s Correlation P value |
0.021 0.855 |
0.033 0.774 |
-0.054 0.631 |
ap value <0.05. C3, complement component 3; C3d, complement component 3d; CI, confidence interval; SD, standard deviation; STGD1, Stargardt disease.