Is There a Relationship between Central and Peripheral Corneal Thickness in Glaucoma Patients?

Abstract

Abstract: : Purpose: To determine the correlation between central and peripheral corneal thickness in glaucoma patients. Materials and Methods: Corneal thickness (CT) was measured with a Micropach 200P+ ultrasonic pachymeter (Sonomed Ultrasound, Inc, Lake Success, NY) in 48 eyes of 24 glaucoma patients that had no prior ocular surgery and were not contact lens wearers. CT measurements were taken centrally (CCT) and at four peripheral (PCT) points 0.75 mm from the limbus: superiorly (SCT) (12 o'clock), inferiorly (ICT) (6 o'clock), nasally (NCT) (3 o'clock OD and 9 o'clock OS), and temporally (TCT) (9 o'clock OD and 3 o'clock OS). Results: CCT for all eyes was lower than any of the PCT (p<0.05, ANOVA, post-hoc Bonferoni t-test). TCT was also lower (p<0.05) than ICT, NCT, SCT, while ICT, NCT, and SCT were similar. Mean CCT and PCT were similar (p>0.05) for contralateral eyes. Correlations between pairs of CT measurements in the same eye was poor with Spearman correlation coefficients (R²) ranging between 0.0125 and 0.2098. CCT of contralateral eyes correlated well with each other (Pearson R²=0.711), however PCT of contralateral eyes correlated poorly with R² (Pearson) ranging from 0.001-0.416. Conclusions: It has been suggested that thin central corneas may indicate an underlying structural deficiency of the eye that results in reduced support to other structures such as the ones surrounding the optic nerve fibers. We found poor correlation between CCT and PCT, suggesting that reduced CCT cannot be used to predict the status of adjacent anterior segment support structures of the eye. Central and Peripheral Corneal Thickness (mm)  

Keywords: intraocular pressure • cornea: clinical science • anterior chamber