Asymmetry Analysis of the Retinal Nerve Fiber Layer Thickness in Normal Eyes using Optical Coherence Tomography

Abstract

In normal subjects without significant anisometropia, there was significant asymmetry of the RNFLT for each eye as well as between the right and left eye.

Intereye asymmetry of optic nerve head parameters and retinal nerve fibre layer thickness in patients with open angle glaucoma detected by spectral domain optical coherence tomography

“…In our study, the mean difference in all quadrants was 4.23 µm. This observation is consistent with the results of other authors, but the difference was smaller and ranged from 0.52 µm to 3.27 µm [8][9][10]. The only difference in ONH parameters was the larger RV in the right eyes.…”

“…The introduction of optical coherence tomography (OCT) into clinical practice has allowed direct measurement of the RNFL thickness. To date, studies that implemented both time domain OCT (TdOCT) and spectral domain OCT (SdOCT) have focused either on circumpapillary RNFL (cpRNFL) analysis or measurement of RNFL thickness in the macular area [8][9][10][11]. These studies have demonstrated a significant increase in the asymmetry of the cpRNFL and total retinal thicknesses at the macula in patients with POAG when compared with a normal population [12][13].…”

Facilitating Glaucoma Diagnosis With Intereye Retinal Nerve Fiber Layer Asymmetry Using Spectral-Domain Optical Coherence Tomography

“…[41][42][43][44][45][46]53,54 This study focuses on asymmetry analysis using the second method and demonstrates that OAG eyes exhibit significantly greater intereye mean RNFL asymmetry compared with normal eyes (Fig. 1).…”

“…RNFL thickness asymmetry can be an early sign of glaucomatous damage and has been explored by OCT technology using 2 main methods: (1) assessing RNFL thickness asymmetry between vertically opposing quadrants of the same eye 41,46,[50][51][52][53] ; and (2) assessing intereye RNFL asymmetry for global average and for quadrants and sectors. [41][42][43][44][45][46]53,54 This study focuses on asymmetry analysis using the second method and demonstrates that OAG eyes exhibit significantly greater intereye mean RNFL asymmetry compared with normal eyes (Fig.…”

“…38 For example, it is well known from population-based studies that 6% to 14% of the normal population have an intereye cup-disc (C/D) ratio asymmetry of 0.2 or more 39,40 ; however, the literature has less information on what is the normal range of RNFL asymmetry as determined by TD-OCT or SD-OCT. In fact, only 4 TD-OCT studies [41][42][43][44] and 2 SD-OCT studies 45,46 have looked at normal intereye RNFL asymmetry. One SD-OCT study was conducted using the Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA) 45 and the other was conducted using the Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany).…”