Abstract
PurposeTo explore factors influencing the inner plexiform layer (IPL) in healthy subjects and to test the hypothesis that IPL thickness is preferentially decreased in glaucoma as compared with ganglion cell layer (GCL) thickness.MethodsNinety-nine glaucomatous eyes and 66 healthy eyes (165 subjects) underwent macular spectral-domain optical coherence tomography (SD-OCT) imaging and GCL and IPL were segmented creating 8 × 8 arrays of 3° × 3° superpixels. The central 24 superpixels were categorized into three levels of eccentricity (∼1.5°, 4.5°, and 7.5° from the foveal center). Linear mixed models were used to determine predictive parameters for IPL thickness in healthy subjects and to explore the influence of diagnosis of glaucoma on IPL thickness taking into account the effect of GCL thickness and other covariates.ResultsBeing located at 4.5° eccentricity predicted thicker IPL compared with 1.5° eccentricity (P < 0.001) in multivariable models in healthy subjects, whereas older age (P = 0.001) and Asian ethnicity (P = 0.021) were associated with thinner IPL. Diagnosis of glaucoma was not associated with thinner IPL regardless of eccentricity after accounting for age and ethnicity. The results were similar when only eyes with mean deviation greater than –6 dB were analyzed.ConclusionsEthnicity and distance from the fovea are the main determinants of IPL thickness in the central macula. Preferential thinning of the macular IPL, compared with GCL, could not be detected in this study regardless of glaucoma stage.Translational RelevanceThere is no evidence for preferential thinning of the macular IPL in glaucoma compared with GCL based on currently available SD-OCT–imaging technology.
Highlights
Detection of glaucoma and its progression is important to treat the disease in a timely manner and to prevent visual disability
Glaucoma eyes had an average visual field mean deviation (MD) of À7.1 (65.2) dB compared with À0.2 (61.2) dB in healthy eyes
Visual field MD was better than À6.0 dB in 52 eyes, was between À6.0 and À12.0 dB in 29 eyes, and worse than À12.0 dB in 18 eyes
Summary
Detection of glaucoma and its progression is important to treat the disease in a timely manner and to prevent visual disability. Glaucoma is caused by retinal ganglion cell (RGC) axonal injury at the level of the optic nerve head. There is growing evidence that measurement of the RGC mass in the macula can contribute to our understanding of neural loss in glaucoma as more than 30% of the RGCs are located within 168 from the fovea.[1] Macular thickness parameters have been demonstrated to perform well for detection of early glaucoma.[2,3] variability of various macular structural parameters is very low and comparable to that of RNFL parameters.[4,5] Improvements in the resolution of spectraldomain optical coherence tomography (SD-OCT)
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.
