Purpose:
This study was performed to compare the effectiveness of scanning laser polarimetry with variable corneal compensation (GDx VCC) and optical coherence tomography (Stratus OCT) for the detection of loss of the retinal nerve fiber layer (RNFL) in preperimetric glaucomatous eyes.
Methods:
In thirty subjects with preperimetric glaucoma (30 eyes) and 19 normal subjects (19 eyes), we measured the retinal nerve fiber layer (RNFL) thickness with GDx VCC and Stratus OCT and analyzed the results by 12-clock-hour RNFL measurements . The AROC (area under the receiver operating characteristic curve) was calculated to determine the diagnostic parameters, and the data from all clock hour segments were compared using regression analysis
Results:
The mean RNFL thickness for GDx VCC was 49.00±17.23 µm and 59.4±68.38 µm (P<0.01), and for Stratus OCT it was 86.43±20.49µm and 106.61±9.57 µm (P<0.01) in the patients with preperimetric glaucoma and normal subjects, respectively. The mean RNFL thickness for the clock hour evaluations were significantly different in comparisons between the patients with preperimetric glaucoma and the normal subjects (P<0.05). In patients with preperimetric glaucoma, the AROC was the highest for the 12 o’clock hour RNFL thickness for GDx VCC (0.905), and the 7 o’clock hour RNFL thickness for the Stratus OCT (0.903). GDx VCC and Stratus OCT RNFL measurements had a significantly high correlation in the superior and inferior quadrants (r>0.750) and low correlation at the nasal quadrant (r=0.210).
Conclusions:
Both GDx VCC and Stratus OCT instruments had similar results at each clock hour segment and both were useful in the early detection of patients with preperimetric glaucoma.
Keywords: imaging/image analysis: clinical