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

Abstract

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 ¼ 37; 56.9%) followed by deepening of the defect (n ¼ 25; 38.5%), appearance of a new defect (n ¼ 6; 9.2%), and widening of the defect away from the macula (n ¼ 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±4.11 (range: 1.1-17.11, n ¼ 37) and 3.4±2.11 (range: 1.1-5.21, n ¼ 5), respectively. No progression was observed on the disc stereophotographs (n ¼ 65) or in the visual fields (n ¼ 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.

Association between the Frequency of Optic Disk Hemorrhage and Progression of NTG Related with the Initial Location of RNFL Defect

“…An RNFL defect in NTG is reported to occur most frequently at the inferotemporal area followed by the superotemporal area [20-22]. DHs have also been observed most frequently in the inferotemporal quadrant [8] followed by the superotemporal quadrant [4, 9].…”

Characteristics of patients with a localized retinal nerve fiber layer defect and normal optic disc appearance

“…To consider some patients in which angle b might be changed, we measured angle g. As we have mentioned above, RNFL defects that changed angle b was 12.5%, and 61.5% of eyes revealed a change in angle a in the report by Suh et al 14 Considering the ratio of the changes in angle a and angle b, we arbitrarily defined angle g to more accurately reflect the initial location of the RNFL defect. Angle g was the angle made by lines 'L' and 'R', which divides angle y into a 2 : 1 ratio from line 'A' to line 'B'.…”

“…We attempted to find the initial location of an RNFL defect to compare the RNFL defect in group A with the glaucomatous RNFL defect in group B. In a report regarding the patterns of progression of RNFL defects in NTG, 14 the widening of the defect away from the macula, corresponding to a change in angle b, occurs in 12.5% of the 65 studied NTG eyes. In the rest of the eyes, angle b was unchanged.…”

Management of Glaucoma in the Era of Modern Imaging and Diagnostics

“…It was noted that almost 95% of these patients exhibited widening of the defect towards the macula, and deepening of the existing defect. Interestingly, no progression was clinically observed on the disc stereo photographs (n=65) or in the visual fields (n=55) in 64 eyes (98.5%) and 46 eyes (83.6%), respectively 61 . Although useful, reproducible high quality red-free images are often difficult and expensive to obtain.…”

“…Prior to the modern imaging techniques further described below, clinicians relied on careful fundoscopic examination and red-free photography to visualize the retinal nerve fiber layer. A recent study by Suh, et al analyzed progressing normal tension glaucoma patients with red-free photography, visual fields, and stereo disc photography 61 . Four characteristic progression patterns were noted including: widening of the existing defect towards the macula, deepening of the defect without expansion, appearance of a new defect, and finally widening of a defect away from the macula.…”