Abstract
Purpose: :
To evaluate sensitivity to detect glaucoma by observer-dependent nerve fiber layer imaging and evaluation using a scanning laser ophthalmoscope.Patients and
Methods: :
One hundred-thirteen eyes of patients with open angle glaucoma (OAG, age 61 ± 12 years, MD -9.87 ± 8.22dB) and 65 eyes of control subjects (age 47 ± 14 years) were included in a retrospective study. Nerve fiber layer imaging was performed manually using a confocal scanning laser ophthalmoscope (SLO, Rodenstock Instr., Argon laser 488nm). Digitized images of the nerve fiber layer were graded off-line by two masked experienced observers. The nerve fiber layer was graded for every single degree (defect or no defect) at 1.7 and 3.4 mm distance to the optic nerve head omitting the nasal 109 degrees. Sensitivity and specificity levels were calculated using ROC-curve analysis.
Results: :
Patients with OAG exhibited nerve fiber layer defects of 103° ± 94° (1.7mm distance) and of 100° ± 93° (3.4mm distance), significantly larger compared to controls (4° ± 13° (1.7mm, p<0.0001) and 4° ± 11° (3.4 mm, p<0.0001)). Sensitivity at 90% specificity was 83% (1.7mm, criterion: defects > 6°) and 79% (3.4mm, criterion: defects > 11°). In early glaucoma (MD < -6dB, n= 39) sensitivity decreased to 77% (1.7mm) and 75% (3.4mm).
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic nerve • imaging/image analysis: clinical