AbstractPurpose To evaluate the strength and pattern of the relationship between the ganglion cell–inner plexiform layer (GCIPL) thickness measured with Cirrus high‐definition (HD)‐OCT and visual field (VF) assessed by standard automated perimetry (SAP).Methods Ninety‐three eyes of 49 glaucoma patients were enrolled. In all patients, parameters of both GCIPL and the peripapillary retinal nerve fiber laye(pRNFL) thickness were measured by Cirrus HD‐OCT (Carl Zeiss Meditec, Dublin, CA). Mean sensitivity(MS) was recorded on the decibel (dB) and 1/L scales. The relationship between function and structure (GCIPL, pRNFL) was sought.Results Correlations were seen between GCIPL sectors and RNFL sectors patients with glaucoma. (r = 0.38–0.792). Average GCIPL thickness and MD correlated most strongly of a strength similar to that demonstrated between average pRNFL thickness and MD. The highest correlations were observed between superior VF cluster (in dB scale) and inferior GCIPL thickness(R2=0.49) or inferior RNFL thickness (R2 = 0.51). Correlations were slightly greater with dB scale than 1/L scale.Conclusion There was a moderate association between the GCIPL thickness and SAP. Cirrus HD‐OCT measurements of the GCIPL relate well with functional loss in patients with glaucomatous optic neuropathy.