The Occurrence and Features of the Atypical Birefringence Pattern in Scanning Laser Polarimetry Using GDxVCC in Healthy Children and Its Impact on the Retinal Nerve Fiber Layer Thickness Values
Abstract
Purpose:To investigate the occurrence and features of the atypical birefringence pattern(ABP) images in scanning laser polarimetry with GDxVCC in healthy children and to assess their impact on retinal nerve fiber layer (RNFL) thickness. Methods:GDxVCC scans in 120 healthy school-aged children were evaluated using typical scan score(TSS)and by subjective grading of the scans.
Results:The ABP was found in 15% of subjects at cutoff value of TSS < 80. Subjective evaluation of the scans raised the frequency of ABP to 20% of subjects.
The mean+/-SD values of TSNIT Average, Superior Average and Inferior Average in 26 eyes with ABP versus 214 eyes with normal birefringence pattern were 66.99+/-7.29um versus 58.00+/-6.22um(P=7.2E to-11),78.43 +/-9.72um versus 72.33+/-8.72um(P=0.001) and 80.87+/-12.01 versus 70.00+/-10.20um(P=0.000001)respectively.Conclusion:The occurrence of ABP in children is not rare and may significatly distort the measured values of the RNFL thickness in TSNIT parameters using GDxVCC.