Masato Kikuchi

Intravitreal injection of bevacizumab for macular edema secondary to branch retinal vein occlusion:results after 12 months and multiple regression analysis.

Purpose: To evaluate the 12-month follow-up results of intravitreal bevacizumab therapy for macular edema secondary to branch retinal vein occlusion and to identify the pretreatment factors that were associated with an improvement of the final visual outcome. Methods: Fifty eyes of 50 patients with macular edema secondary to branch retinal vein occlusion received an injection of 1.25 mg/0.05 mL bevacizumab. Additional injections were done when recurrence of macular edema occurred or the treatment was not effective. The best-corrected visual acuity and foveal thickness were measured. Stepwise multiple regression analyses were also performed. Results: The mean logarithm of the minimum angle of resolution visual acuity improved significantly from 0.53 to 0.26, and the mean foveal thickness decreased significantly from 523 to 305 &mgr;m during the 12-month follow-up period. The mean number of injections was 2.0 (range, 1–4). Stepwise multiple regression analyses showed that younger patients had both better visual acuity at 12 months and greater improvement of visual acuity during 12 months. In addition, better pretreatment visual acuity was associated with better visual acuity at 12 months but with less improvement of the visual acuity. Conclusion: Intravitreal bevacizumab therapy can be a long-term effective treatment for macular edema secondary to branch retinal vein occlusion.

C9-R95X Polymorphism in Patients with Neovascular Age-Related Macular Degeneration

PURPOSE A non-sense mutation at codon 95 in the gene encoding complement factor C9 (C9-R95X) is found most frequently among Japanese. The authors investigated the association between C9-R95X and Japanese patients with neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV). METHODS The presence of the C9-R95X polymorphism was assessed by direct sequencing in Japanese patients with either PCV (n = 105) or neovascular AMD (n = 198) and 396 control subjects. Multivariate regression analyses were conducted. Photocoagulation was applied in the eyes of mice with a heterozygous defect in the C3 gene and control wild-type mice. Photocoagulation was also applied to wild-type mice before either anti-C9 antibody or isotype IgG was injected into the eyes. The eyes were collected later for measurement of vascular endothelial growth factor (VEGF) and histological evaluation of choroidal neovascularization (CNV). RESULTS The frequency of those with one or two C9-R95X variants was lower in neovascular AMD (2.02%) than in PCV (5.71%) and controls (6.05%). The presence of C9-R95X conferred a 4.7-fold reduction (95% confidence interval, 1.2-18.1; P = 0.021) in the risk for neovascular AMD after adjusting for the major AMD risk factors. A heterozygous defect in the C3 gene was associated with the reduced growth of laser-induced CNV, as was intraocular injection of anti-C9 antibody. This reduced CNV growth was accompanied by a decreased level of secreted VEGF in the intraocular fluid. CONCLUSIONS These findings support the notion that the haploinsufficiency of C9, a terminal complement complex component, engenders reduced intraocular secretion of VEGF and decreased risk for CNV development.

Seasonal variations of acute massive submacular haemorrhage associated with age-related macular degeneration

Aims: To determine whether there is a seasonal variation in the onset of acute, massive submacular haemorrhage associated with age-related macular degeneration. Methods: Sixty eyes of 59 patients diagnosed between April 1998 and March 2005, were studied retrospectively. For each patient, the month and season of onset of the submacular haemorrhage and the mean monthly ambient temperature in Nagoya were analysed. Any history of systemic hypertension was also recorded, and the seasonal variations were also investigated in hypertensive and non-hypertensive groups. Results: The number of cases peaked in winter with a trough in summer, and this seasonal variation was significant (Roger’s R = 12.03, p<0.01). The monthly incidence was inversely correlated with the temperature (Spearman’s rank correlation coefficient r = 0.89, p<0.01). The seasonal variations were significant in the hypertensive group but not in the non-hypertensive group. Conclusion: The considerable seasonal variations suggests that the mechanism for the haemorrhage is strongly correlated with the systemic blood pressure.

New algorithm to analyze optical coherence tomographic images quantitatively

PurposeTo determine whether an algorithm we have developed can be used to measure the retinal thickness on optical coherence tomography (OCT) images.MethodsSix radial linear scans of 6 mm were made with the OCT instrument. The retinal thickness and volume determined with the built-in algorithm for the OCT instrument for 50 eyes of 50 control subjects with normal retinal boundaries were compared to the values obtained with our algorithm. The macular volume was also measured in 26 eyes of 25 subjects before and after photodynamic therapy (PDT).ResultsThe values obtained by the two algorithms in normal retinas were strongly correlated (R = 0.99). Bland-Altman plots of the mean differences between the two algorithm measurement values showed excellent agreement. The mean macular volume determined before and 1 week after PDT with the built-in algorithm was significantly larger than that measured with our algorithm (P = 0.035 pre-PDT; P = 0.004 1 week after PDT).ConclusionsOur algorithm can be used to obtain a valid measurement of retinal thickness in normal retinas. The macular volume before and 1 week after PDT obtained with the built-in algorithm was larger than those measurements obtained with our algorithm.