title: Relationship between grades of macular perfusion and foveal thickness in branch retinal vein occlusion.
abstract: BACKGROUND
  To study the relationship between retinal perfusion around the macula and the foveal thickness in branch retinal vein occlusion (BRVO).
  
  
  METHODS
  Seventy-four eyes of 74 consecutive patients with BRVO were enrolled. We developed a new grading system to evaluate the status of retinal perfusion around the macula in three grades: full perfusion area (FPA), partial perfusion area (PPA), and nonperfusion area (NPA), using fluorescein angiography. The correlation was assessed between these grades and the central foveal thickness (CFT) measured by optical coherence tomography. We also determined the area with the closest correlation between the perfusion status and the foveal thickness by comparing the correlation coefficient in areas of 1-, 2-, and 3-disc diameter (DD) horizontal hemicircles centered at the fovea. The correlation was determined between the extent of each perfusion grade and CFT.
  
  
  RESULTS
  We found a significant negative correlation between the CFT and the FPA (r = 0.31, P = 0.006) and a significant positive correlation between the CFT and the PPA (r = 0.45, P < 0.001) in the three areas. The most significant correlations were found in the 2-DD area. Interestingly, the NPA has not correlated with the foveal thickness in any areas.
  
  
  CONCLUSIONS
  The areas of partial but not complete capillary loss seem to be responsible for the macular edema associated with BRVO. Treatments targeting leakage from the dilated capillaries in the PPA should be investigated.
authors: Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Japan.
authors: Susumu
authors: S
authors: Sakimoto
authors: Motohiro
authors: M
authors: Kamei
authors: Mihoko
authors: M
authors: Suzuki
authors: Shinsaku
authors: S
authors: Yano
authors: Nagakazu
authors: N
authors: Matsumura
authors: Hirokazu
authors: H
authors: Sakaguchi
authors: Fumi
authors: F
authors: Gomi
authors: Kohji
authors: K
authors: Nishida
keywords: branch retinal vein occlusion; foveal thickness; macular edema; macular perfusion