Abstract
PurposeTo report an asymmetry analysis of macular inner retinal layers using swept-source optical coherence tomography (OCT) and to evaluate the utility for glaucoma diagnosis.DesignObservational, cross-sectional study.ParticipantsSeventy normal healthy subjects and 62 glaucoma patients.MethodsThree-dimensional scans were acquired from 70 normal subjects and 62 open angle glaucoma patients by swept-source OCT. The thickness of the retinal nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), ganglion cell complex, and total retina were calculated within a 6.2×6.2 mm macular area divided into a 31×31 grid of 200×200 μm superpixels. For each of the corresponding superpixels, the thickness differences between the subject eyes and contra-lateral eyes and between the upper and lower macula halves of the subject eyes were determined. The negative differences were displayed on a gray-scale asymmetry map. Black superpixels were defined as thickness decreases over the cut-off values.ResultsThe negative inter-ocular and inter-hemisphere differences in GCIPL thickness (mean ± standard deviation) were -2.78 ± 0.97 μm and -3.43 ± 0.71 μm in the normal group and -4.26 ± 2.23 μm and -4.88 ± 1.46 μm in the glaucoma group. The overall extent of the four layers’ thickness decrease was larger in the glaucoma group than in the normal group (all Ps<0.05). The numbers of black superpixels on all of the asymmetry maps were larger in the glaucoma group than in the normal group (all Ps<0.05). The area under receiver operating characteristic curves of average negative thickness differences in macular inner layers for glaucoma diagnosis ranged from 0.748 to 0.894.ConclusionsThe asymmetry analysis of macular inner retinal layers showed significant differences between the normal and glaucoma groups. The diagnostic performance of the asymmetry analysis was comparable to that of previous methods. These findings suggest that the asymmetry analysis can be a potential ancillary diagnostic tool.
Highlights
Healthy organ pairs mostly show symmetric anatomic features
The numbers of black superpixels on all of the asymmetry maps were larger in the glaucoma group than in the normal group
The diagnostic performance of the asymmetry analysis was comparable to that of previous methods. These findings suggest that the asymmetry analysis can be a potential ancillary diagnostic tool
Summary
The retinal layers show significant symmetry between the right and left eyes. The occurrence and progression of clinical disease are often asymmetric between the right and left eyes. This opens up the possibility that evaluation of the inter-ocular symmetry of retinal layers can help detect glaucomatous changes. Several studies have reported the inter-ocular asymmetry of the peripapillary retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT). A recent study showed significant inter-ocular symmetry of ganglion cell-inner plexiform layer (GCIPL) thickness measured by spectral-domain OCT in normal healthy eyes. A recent study showed significant inter-ocular symmetry of ganglion cell-inner plexiform layer (GCIPL) thickness measured by spectral-domain OCT in normal healthy eyes. [7] SullivanMee et al have evaluated diagnostic capabilities of inter-ocular differences in total macular thickness, and inter-ocular macular thickness asymmetry showed the highest diagnostic sensitivity between early glaucoma patients and controls. [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
