Abstract
Purpose::
To compare the measurement of central corneal thickness (CCT) by Visante anterior segment optical coherence tomography (AS-OCT) with that made by ultrasound pachymetry
Methods::
This was part of a population-based cross-sectional study of 3,280 Malay subjects in Singapore. Subjects were Singaporean Malay adults aged 40-80 years residing in the south-western part of Singapore. They were invited to a centralized clinic for a standardized assessment of best-corrected visual acuity, interview, clinical examination and ocular imaging. Approximately 10% of subjects underwent evaluation of CCT by both AS-OCT (Visante, Carl Zeiss Meditec, Dublin, CA) and ultrasound pachymetry (Sonomed A2500, Haag-Streit). CCT measured by AS-OCT and ultrasound were compared using Bland Altman analysis.
Results::
285 consecutive subjects were included. There were 145 men (50.9%) and 140 women (49.1%) examined, and the mean age was 57.9 + 10.8 years. The mean CCT measured by AS-OCT and ultrasound pachymetry were 527.0 ± 34.1 and 542.3 ± 36.7 respectively. CCT as measured by ultrasound pachymetry was highly correlated with the equivalent AS-OCT reading (Spearman’s correlation coefficient = 0.93, p<0.001). However, Bland-Altman analysis showed that ultrasound pachymetry measurements were significantly higher, with mean difference of 16.7 ± 11.9microns (p < 0.001, 95% CI: 15.5 to 18.1).
Conclusions::
CCT measured by Visante AS-OCT is highly correlated with that of ultrasound pachymetry. However, CCT readings by Visante AS-OCT were consistently less than that of ultrasound pachymetry.
Keywords: cornea: basic science • clinical (human) or epidemiologic studies: systems/equipment/techniques • depth