Abstract
Purpose :
To compare three circular peripapillary retinal nerve fiber layer (pRNFL) thickness measurements in three standardized diameter sizes from the Bruch’s membrane opening (BMO) center of optic nerve head (ONH) by spectral domain optical coherence tomography (SD-OCT) and to assess the specific diagnostic power for glaucoma detection.
Methods :
In this case-control, cross-sectional study, 642 eyes of 413 participants could be included. 445 eyes with diagnosed glaucoma and 197 eyes of healthy controls underwent SD-OCT of the ONH, visual field testing, and clinical examination. Peripapillary RNFL thickness was measured by circular scans in 3.5 mm (C1), 4.2 mm (C2) and 4.7 mm (C3) distance from the BMO center of the ONH. Receiver operating characteristics (ROC) analysis was used to assess diagnostic power for glaucoma detection.
Results :
BMO area was 1.89±0.04mm2. In C1, mean global pRNFL was 69.92±18.3µm in glaucomatous eyes and 93.45±9.9µm in controls. In C2, mean global pRNFL was 61.32±14.9µm in glaucomatous eyes and 80.40±8.3µm in controls. In C3, mean global pRNFL was 55.20±112.8µm in glaucomatous eyes and 70.77±6.7µm in controls. Using ROC analyses, the calculated area under the curve (AUC) to differentiate glaucoma was 0.852 for pRNFL in C1, 0.843 in C2, and 0.838 in C3. AUCs of pRNFL measurements in ONH sectors ranged from 0.699 to 0.841 for all three circles and did not excel AUC of the best scoring global parameter.
Conclusions :
In healthy and in glaucomatous ONH’s, peripapillary RNFL thickness decreased with increasing distance to the BMO center. In comparison of three standardized diameters to measure pRNFL, the inner circle at 3.5 mm distance to the BMO center showed the highest diagnostic power to differentiate glaucoma from healthy controls. Levels of diagnostic power of wider circular scans were comparable. Diagnostic power of sectorial pRNFL measurements was non-superior.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.