Comparison of macular choroidal thickness in patients with pseudoexfoliation syndrome to normal control subjects with enhanced depth SD-OCT imaging

Abstract

Purpose: To test the hypothesis that macular choroidal thickness is lower in patients with pseudoexfoliation syndrome (PXS) as compared to healthy control subjects. Methods: In this cross-sectional, observational study, 38 non-glaucomatous PXS subjects and 37 healthy volunteers were enrolled in a tertiary care Glaucoma Clinic. The macular region was scanned with the enhanced depth imaging (EDI) protocol of a spectral domain optical coherence tomography (SD-OCT) device (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany). Macular choroidal thickness and volumes were compared in nine sectors of the Early Treatment Diabetic Retinopathy Study (ETDRS) layout profile across the central 3.45 mm zone after manual segmentation of the choroidal thickness. Linear mixed modeling was used to adjust for confounding variables. Results: Six PXS eyes and 8 control eyes were excluded due to poor image quality leaving 32 PXS and 29 control eyes for final analyses. The average age and axial length of the PXS and control groups were 67.94 ± 7.30 vs 64.86 ± 7.04 and 22.91 ± 0.77 vs 23.24 ± 0.66 mm, respectively, (P = 0.10 and 0.20). There was no significant difference in retinal nerve fiber layer (RNFL) thickness between the two groups (P = 0.24). The choroidal thickness was significantly lower in the central subfield subfoveal area (P = 0.02) and in the inner superior (P = 0.03) and inner nasal quadrants (P = 0.03) in the PXS group compared to the control group, as was the choroidal volume (P = 0.02). No significant difference was found in macular choroidal thickness after adjusting for age, gender, and axial length. While there was a significant negative association between age and central subfield choroidal thickness in the control group (r = −0.48, P = 0.01), this association was not significant in the PXS group (r = −0.08, P = 0.68). Conclusions: Our findings demonstrate that the choroid does not seem to be significantly altered in PXS eyes. Choroidal thickness changes need to be explored in PXS eyes with glaucoma. Keywords: Pseudoexfoliation, Choroid, Optical coherence tomography