Ganglion Cell Complex Assessed by Spectral-Domain Optical Coherence Tomography in Normal Older Adults from the City of Parintins, Brazilian Amazon Region

Abstract

Purpose: To provide normative values of ganglion cell complex (GCC) and its possible associations with retinal nerve fiber layer (RNFL) thickness in a subset of participants of a population-based ocular eye survey using spectral-domain optical coherence tomography (SD-OCT).

Methods: The Brazilian Amazon Region Eye Survey (BARES) is an ongoing population-based prevalence study of visual impairment, blindness and ocular diseases in adults aged 45 years and older from urban and rural areas of Parintins city, Brazil. GCC and RNFL measurements were obtained through dilated pupils using iVue-100 SD-OCT in a subset of participants with presenting distance visual acuity≥20/32, normal eye exam and absence of previous ocular surgery. CCG and RNFL thickness (µm) was measured overall and also for superior (SH) and inferior hemispheres (IH). Data from one randomly-chosen eye of each participant were analyzed and a multiple linear regression model was performed to investigate the effects of age, gender and cup-to-disc area ratio on CCG. Pearson’s correlation was used to compare GCC with RNFL parameters.

Results: Out of 1180 participants, 64 (36 females) were eligible for this study. Age ranged from 45 to 65 years (mean=52±5 years). Considering GCC parameters, overall, SH and IH thickness were respectively 94.42±9.25µm, 95.98±8.22µm and 94.79±7.78µm. The mean overall RNFL thickness was 104.16±9.15µm, with thickest RNFL in the SH (107.03±10.55µm), followed by the IH (104.36±10.81µm). Pearson correlation showed moderate and significant association (p<0.001) between GCC and RNFL for overall (r=0.588), SH (r=0.542) and IH (r=0.537). There were no significant correlations of GCC thickness with gender, age and cup-to-disc area ratio.

Conclusions: The current results provided a normative database of ganglion cell complex parameters as well as its association with retinal nerve fiber layer in this cohort. These data might be useful for glaucoma diagnosis and progression monitoring in this population.