Objective　To determine the effect of posterior vitreous detachment on the prognosis of branch retinal vein occlusion　(BRVO).　Methods　One hundred and sixteen patients (116 eyes) with BRVO who underwent vitreous examination were retrospectively studied.The relationship of vitreous conditions to posterior segment neovascularization and macular edema was statistically investigated.　Results　In 40 ischemic cases,12 of 25 eyes (48.0%) with no posterior vitreous detachment (PVD) or partial PVD developed retinal or optic disc neovascularization ,or both,but only one of the 15 eyes (6.7%) with complete PVD developed neovascularization during a mean follow-up period of 10.7±2.2 months　(P＜0.05).Diffuse macular edema was found in 45 eyes　(38.8%).The incidence of macular edema was significantly higher in eyes with vitreomacular attachment　(51.5%)　than in those with vitreomacular separation　(22.0%)(P＜0.01).　Conclusion　It was suggested that complete PVD may play a role in protecting eyes with BRVO from posterior segment neovascularization and macular edema.

Objective To diagnose a rare variant Hb Shaare Zedek in a Chinese family,and describe its clinical feature.Methods Blood samples of seven members of three generation were collected.Standard blood routine analysis,hemoglobin electrophoresis and blood gas analysis were used for phenotype analysis.Gap-PCR and reverse dot blot analysis were used to detect common thalassemia mutations.DNA sequence analysis of the human α and β globin genes were used to identify the mutation site of these samples.Results The result of blood routine analysis was normal in the proband,but a abnormal hemoglobin band (22.4％,capillary assay) was found by hemoglobin electrophoresis.In the blood gas analysis,the partial pressure of oxygen and blood oxygen saturation were 72.0 mm Hg ( 1 mm Hg =0.133 kPa) and 93.0％ in the proband.The heterozygous mutations in αl globin gene at codon 56 ( AAG ＞ GAG)which leaded Glu substitution to Lys were identified in the proband.Other family members who carried the same mutation showed similar phenotype,with abnormal hemoglobin band ( 22.4％ - 23.9％,capillary assay),low partial pressure of oxygen (59.0 - 72.0 mm Hg) and blood oxygen saturation (91.0％ -93.0％).Conclusions The heterozygote of Hb Shaare Zedek leads to slight symptoms with abnormal hemoglobin band,decreased partial pressure of oxygen and blood oxygen saturation.Discovery of this mutation enriches the abnormal hemoglobin spetrum of Chinese people,and it is useful for the clinical diagnosis and genetic counseling of hemoglobinopathies.