No abstract

Aim To investigate whether the aqueous levels of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) are correlated to the vitreous levels of these substances and to the severity of macular oedema in branch retinal vein occlusion (BRVO). Methods Aqueous and vitreous samples were obtained during cataract and vitreous surgery from 24 patients (24 eyes) with macular oedema in BRVO. The VEGF and IL-6 levels in aqueous humour, vitreous fluid, and plasma were determined by enzyme-linked immunosorbent assay. The degree of retinal ischaemia was evaluated in terms of the area of capillary nonperfusion using the Scion Image. The severity of macular oedema was evaluated using the OCT. Results The aqueous level of VEGF was significantly correlated with the vitreous level of VEGF (Po0.0001). Vitreous levels of VEGF and IL-6 were significantly correlated with the nonperfusion area of BRVO (Po0.0001, P ¼ 0.0061, respectively), as were the aqueous levels of VEGF and IL-6 (Po0.0001, P ¼ 0.0267, respectively). Furthermore, the vitreous levels of VEGF and IL-6 and the aqueous level of VEGF were significantly correlated with the severity of macular oedema of BRVO (P ¼ 0.0001, P ¼ 0.0331, P ¼ 0.0272, respectively). Conclusion Our results suggest that the aqueous level of VEGF may reflect its vitreous level. Measurement of the aqueous level of VEGF may be clinically useful to indicate the severity of macular oedema with BRVO.

The levels of VEGF and IL-6 are increased in patients with macular edema with BRVO and are significantly correlated with the size of the nonperfusion area and the severity of macular edema. Therefore, they may play a role in macular edema with BRVO.

Recent evidence argues against a high threshold dose for vision-impairing radiation-induced cataractogenesis. We conducted logistic regression analysis to estimate the dose response and used a likelihood profile procedure to determine the best-fitting threshold model among 3761 A-bomb survivors who underwent medical examinations during 2000-2002 for whom radiation dose estimates were available, including 479 postoperative cataract cases. The analyses indicated a statistically significant dose-response increase in the prevalence of postoperative cataracts [odds ratio (OR), 1.39; 95% confidence interval (CI), 1.24-1.55] at 1 Gy, with no indication of upward curvature in the dose response. The dose response was suggestive when the restricted dose range of 0 to 1 Gy was examined. A nonsignificant dose threshold of 0.1 Gy (95% CI, <0-0.8) was found. The prevalence of postoperative cataracts in A-bomb survivors increased significantly with A-bomb radiation dose. The estimate (0.1 Gy) and upper bound (0.8 Gy) of the dose threshold for operative cataract prevalence was much lower than the threshold of 2-5 Gy usually assumed by the radiation protection community and was statistically compatible with no threshold at all.

To obtain the best statistical model for a previous study of cataract prevalence in atomic-bomb survivors, we tested the fitness of the threshold model in an updated dataset of the study, utilizing re-diagnosis by a single ophthalmologist, use of the DS02 dosimetry system, and separation of the in utero group. The results suggest that, in 730 atomic-bomb survivors, we cannot conclude thresholds are greater than 0 Sv in cortical cataract and posterior sub-capsular opacity since the lower 90% confidence limits of the thresholds were 0 Sv. Threshold dose point estimates were 0.6 Sv (90% CI, <0.0-1.2 Sv) and 0.7 Sv (90% CI, <0.0-2.8 Sv) for cortical cataract and posterior sub-capsular opacity, respectively. Detailed regression analyses with no threshold model showed that nuclear color and nuclear opacity have no dose responses (p > 0.40). Cortical cataract showed a significant dose effect (p = 0.002), with an odds ratio (OR)/Sv of 1.30 (95% CI, 1.10-1.53) and no dose-effect modifiers. Posterior sub-capsular opacity showed a significant dose effect (p < 0.001), with an OR/Sv of 1.44 at age of exposure of 10 y (95% CI, 1.19-1.73). The dose effect decreased significantly with increasing age at exposure (p = 0.022). No dose response was observed for in utero survivors (p > 0.20).