Helvacioglu reproducibility index: a new algorithm to evaluate the effects of misalignments on the measurements of retinal nerve fiber layer by spectral-domain OCT

• Published in: International journal of ophthalmology 2015, Vol.8 (5), p.1008-1012
• Main Authors: Helvacioglu, Firat, Uyar, Osman Murat, Sencan, Sadik, Tunc, Zeki, Kapran, Ziya
• Format: Article
• Language: English
• Subjects: Clinical Research; misalignment; optical coherence tomography; repeatability; reproducibility; retinal nerve fiber layer
• ISSN: 2222-3959; 2227-4898
• DOI: 10.3980/j.issn.2222-3959.2015.05.28

To evaluate the effect of misalignment on the measurements of retinal nerve fiber layer (RNFL) by spectral-domain optical coherence tomography (OCT). A total of 42 eyes from 21 healthy young subjects underwent RNFL measurements with RTVue spectral-domain OCT (Optovue Inc., Fremont, California, USA). Two baseline measurements with perfectly aligned central circle to the borders of the optic nerve and four misaligned measurements which were misaligned towards to four quadrants were taken. The differences in RNFL between the baseline and misaligned measurements were analyzed with a new algorithm called Helvacioglu reproducibility index (HRI) which is designed to measure the reproducibility of the scans by evaluating the RNFL changes in the four main quadrants. The average RNFL scores of the first two baseline measurements have good correlation (c=0.930) and good reproducibility scores (0.15±0.07). Superior misaligned measurements had significantly lower superior quadrant score and higher inferior quadrant score, similar nasal and little higher temporal scores (P1, P2