Significant correlation between electroretinogram parameters and ocular vascular endothelial growth factor concentration in central retinal vein occlusion eyes.

PURPOSE: Central retinal vein occlusion (CRVO) leads to retinal ischemia, which then induces an upregulation of vascular endothelial growth factor (VEGF). The aim of this study was to determine whether a significant correlation exists between the ocular VEGF levels and the amplitudes and implicit times of different components of the electroretinogram (ERG) in eyes with a CRVO. METHODS: The medical records of the 20 consecutive patients who had macular edema secondary to CRVO and were examined at the Nagoya University Hospital from November 2008 to February 2010 were reviewed. Because all the patients were scheduled to receive an intravitreal injection of bevacizumab (IVB), it was possible to collect samples of the aqueous humor before the IVB. The correlation between the different components of the ERGs and the VEGF concentration in the aqueous was determined. RESULTS: The mean VEGF concentration of the aqueous humor was 416 pg/mL with a range of 100-1260 pg/mL. The b/a ratio of the single flash ERGs (P = 0.049; ρ = -0.45), implicit times of the cone a-wave (P = 0.028; ρ = 0.50), cone b-wave (P = 0.0059; ρ = 0.63), and 30 Hz flicker ERGs (P = 0.0058; ρ = 0.63) were significantly correlated with the VEGF concentration in the aqueous. CONCLUSIONS: The significant correlations between the different components of the ERGs and the aqueous VEGF concentration indicate that full-field ERGs can be used to detect the CRVO patients at a high risk of developing neovascularization of the iris.

Rebound of macular edema after intravitreal bevacizumab therapy in eyes with macular edema secondary to branch retinal vein occlusion.

PURPOSE: To determine the incidence of rebound macular edema after intravitreal bevacizumab in eyes with macular edema secondary to branch retinal vein occlusion and to identify the pretreatment factors that were significantly associated with the rebound. METHODS: The changes in the foveal thickness after the intravitreal bevacizumab (1.25 mg/0.05 mL) were studied in 65 eyes of 65 patients with macular edema secondary to branch retinal vein occlusion. A rebound of macular edema was defined as a ≥110% increase in the foveal thickness or a foveal thickness ratio of ≥110% (foveal thickness at the recurrence/foveal thickness at the baseline × 100). Multivariate logistic regression analyses and subgroup analyses were performed to determine which pretreatment factors were associated with the rebound. RESULTS: Seven of 65 eyes (10.8%) showed a rebound (≥110% of baseline thickness). Subgroup analyses showed that a thinner pretreatment fovea and a shorter interval between symptom onset to the initiation of the intravitreal bevacizumab were significantly associated with a rebound of macular edema (P < 0.01). The interval from symptoms onset to the initiation of treatment was <8 weeks in all 7 eyes with a rebound macular edema. CONCLUSION: These results suggest that a rebound of macular edema in eyes with branch retinal vein occlusion was more likely to occur when the intravitreal bevacizumab therapy is initiated before the macular edema reaches the maximum level. Rebound of macular edema may be effectively avoided by waiting at least 8 weeks after the onset of symptoms to begin the intravitreal bevacizumab.

Changes in areas of capillary nonperfusion after intravitreal injection of bevacizumab in eyes with branch retinal vein occlusion.

PURPOSE: : To study the effect of an intravitreal bevacizumab (IVB) on the retinal ischemia in eyes with a branch retinal vein occlusion. METHODS: : Fluorescein angiography was performed before and 1 month after the IVB (1.25 mg/0.05 mL) in 58 consecutive eyes of 58 patients with macular edema secondary to a branch retinal vein occlusion. The area of capillary nonperfusion was measured on an early-phase fluorescein angiography image by an area measurement program, and the area was expressed relative to the optic disk area (DA). A blockage of the fluorescence by the retinal hemorrhage was distinguished from nonperfusion by comparisons with retinal photographs. RESULTS: : Thirty-seven of 58 eyes did not have any capillary nonperfusion before the IVB, and capillary nonperfusion developed in 3 of these 37 eyes 1 month after the IVB. The area of nonperfusion in these 3 eyes was 0.13, 0.47, and 0.60 DA. Twenty-one of the 58 eyes had capillary nonperfusion before the IVB, and the mean (±SD) area of nonperfusion was 3.45 ± 4.66 DA before the IVB and 3.45 ± 5.19 DA 1 month after the IVB. This change was not significant (P = 0.36). An increase in the area of capillary nonperfusion of >1.0 DA after the IVB was seen in only 1 of all 58 eyes. CONCLUSION: : These results suggest that the incidence of a significant increase in the area of capillary nonperfusion (>1 DA) during the 1 month after the IVB is very low in eyes with branch retinal vein occlusion.

Comparison of effectiveness of two 10% carbamide peroxide tooth-bleaching systems using spectrophotometric measurements.

PURPOSE: The purpose of this study was to compare the color changes achieved with two commonly used bleaching systems on the basis of a spectrophotometric analysis. MATERIALS AND METHODS: Two commercially available 10% carbamide peroxide bleaching systems were used by a total of 48 individuals. Subjects who had intact natural maxillary anterior teeth void of any restorations or decay that had not been subjected to any prior bleaching were included. Opalescence 10% PF (Ultradent Products Inc., South Jordan, UT, USA) was used by 23 patients for 14 days, whereas Nite White Excel (Discus Dental, Culver City, CA, USA) was applied by 25 patients for the same duration. Tooth colors for the middle one-third region of maxillary central incisors and canines were measured with a spectrophotometer prior to bleaching and after 14 days of bleaching. Color difference deltaE and color coordinates L* (lightness), a* (redness), and b* (yellowness) of CIELAB color system (developed by the Commission Internationale de l'Eclairage) were calculated. RESULTS: Mean deltaE values for Opalescence ranged from 5.03 to 8.92 and from 5.84 to 9.61 for Nite White. The most significant factor of the color change was b* followed by L* and a*. L* values were higher after bleaching, whereas values for both a* and b* decreased. There were no significant differences between the two systems examined (p < .05).