Evaluation of a new scoring system for retinal nerve fiber layer photography using HRA1 in 964 eyes

Abstract

Purpose: To evaluate retinal nerve fiber layer (RNFL) defect by a new scoring system for RNFL photography using the Heidelberg Retina Angiograph 1 (HRA1).

Methods: This retrospective study included 128 healthy eyes and 836 primary open-angle glaucoma eyes. The RNFL photography using HRA1 was interpreted using a new scoring system, and correlated with visual field indices of standard automated perimetry (SAP). Using the presence of RNFL defect, darkness, width, and location, we established the new scoring system of RNFL photos.

Results: The mean RNFL defect score I in the early, moderate, severe, and control groups were 7.3, 9.2, 10.4, and 3.6, respectively. The mean RNFL defect score II in the early, moderate, severe, and control groups were 14.5, 28.5, 43.4, and 3.4, respectively. Correlations between the RNFL defect score II and the mean deviation of SAP was the strongest of the various combinations (r=-0.675, P<.001).

Conclusions: Using a new scoring system, we propose a method for semi-quantitative interpretation of RNFL photographs. This scoring system may be helpful to distinguish between normal and glaucomatous eyes, and the score is associated with the severity of visual field loss.

Fig. 1

Location scores of retinal nerve fiber layer defect scoring system. Score "1" represents inferotemporal or superotemporal area, "2" represents nasal area, and "3" represents temporal area.

Fig. 2

(a) Correlations between the retinal nerve fiber layer defect score I and mean deviation of standard automated perimetry(SAP). Y=6.192-0.251 X, r=-0.528, P<0.001. (b) Correlations between the retinal nerve fiber layer defect score II and mean deviation of SAP. Y=9.515-1.772 X, r=-0.675, P<0.001. MD=mean deviation; RNFL=retinal nerve fiber layer.

Fig. 3

(a) Correlations between the retinal nerve fiber layer defect score I and pattern standard deviation of standard automated perimetry (SAP). Y=5.841+0.380 X, r=0.481, P<0.001. (b) Correlations between the retinal nerve fiber layer (RNFL) defect score II and pattern standard deviation (PSD) of standard automated perimetry (SAP). Y=7.642+2.542 X, r=0.581, P<0.001. PSD= pattern standard deviation; RNFL=retinal nerve fiber layer.

Fig. 4

Correlations between the retinal nerve fiber layer defect score II and mean deviation of standard automated perimetry in early stage glaucoma and control group. Y=2.849-2.386 X, r=-0.313, P<0.001. MD=mean deviation; RNFL=retinal nerve fiber layer.

Fig. 5

Examples of interpretation of the retinal nerve fiber layer photographs using HRA1. (a) Early stage glaucoma patient (MD -1.59 dB, PSD 2.60 dB). RNFL defect, darkness, width, and location score are 1 (suspicious defect), 1 (slight), 1 (< 45(), and 1 (superotemporal), respectively. RNFL defect score I is 4, and RNFL defect score II is 1. (b) Moderate advanced glaucoma patient (MD -6.77 dB, PSD 10.81 dB). RNFL defect, darkness, width, and location score are 2 (definite defect), 2 (moderate), 2 (45° - 90° ), and 1 (inferotemporal), respectively. RNFL defect score I is 7, and RNFL defect score II is 8. Blue lines indicated RNFL defect area.