Patterns of progression of localized retinal nerve fibre layer defect on red-free fundus photographs in normal-tension glaucoma

Purposes To investigate patterns of progression of localized retinal nerve fibre layer (RNFL) defect on red-free fundus photographs and to quantify extents of progression in normal-tension glaucoma (NTG) patients. Methods Sixty-five eyes of consecutive 65 NTG patients who had shown progression of localized RNFL defect on serial red-free fundus photographs were selected for this study. Patterns of progression of localized RNFL defect on red-free fundus photographs were categorized and extents of progression were quantified. Serial assessments of disc stereophotographs and visual fields were also performed to detect progression. Results The most common pattern of progression was widening of the defect towards the macula (n = 37; 56.9%) followed by deepening of the defect (n = 25; 38.5%), appearance of a new defect (n = 6; 9.2%), and widening of the defect away from the macula (n = 5; 7.7%). Eight eyes simultaneously showed two patterns of progression. Mean angular widening of the defect towards the macula and away from the macula was 6.4 +/- 4.1 degrees (range: 1.1-17.1 degrees, n = 37) and 3.4 +/- 2.1 degrees (range: 1.1-5.2 degrees, n = 5), respectively. No progression was observed on the disc stereophotographs (n = 65) or in the visual fields (n = 55) in 64 eyes (98.5%) and 46 eyes (83.6%), respectively. Conclusions There were four patterns of progression of localized RNFL defect. In most cases, RNFL loss proceeded temporally. Eye (2010) 24, 857-863; doi:10.1038/eye.2009.209; published online 14 August 2009