Measurement of Optic Disc Size and Rim Area with Spectral-Domain OCT and Scanning Laser Ophthalmoscopy

Abstract

HRT overestimated optic disc area as compared to SD-OCT. A portion of the difference in HRT and SD-OCT disc measurements is due to HRT's magnification correction algorithm. Rim area measurements from HRT were larger than from SD-OCT, likely a result of different definitions for the reference plane and differences in disc area measurements. Disc parameters from the two devices are not interchangeable.

Change in choroidal thickness and the relationship with accommodation following myopic excimer laser surgery

“…34 Eye magnification was corrected using Bennett's formula (axial length-corrected measurements) in previous studies. 35 In our study, there was no significant difference in axial length before and after surgery and we speculated that there was no significant magnification effect in CT of the same individual before and after surgery.…”

Gender- and Ethnicity-Related Differences in Optic Nerve Head Topography in Healthy Indian and Caucasian Participants

“…4,5,17 The Copernicus OCT device used in the present study was able to resolve up to 3 mm in the axial plane, which is significantly better than most other commercially available OCT devices. Improvements in axial resolution are likely to lead to more accurate measurement of disk margins in the future due to less ambiguity in resolving the edges of the RPE.…”

Quantifying Structures in the Ocular Fundus

“…1 The measurements correspond better with an attempt to correct for optical magnification (by taking into account axial length of the eye). However, the definition of ''the edge of the disc,'' which enters into calculations of the disc area and rim area, is not the same for these two instruments.…”