• Intro
• Abstract
• The Cornea
• Equipment
• Results
• Methods
• Papers
• The team
• References

Pachymetry Study Abstract

Purpose: To compare the accuracy of central corneal thickness measurements with optical low-coherence reflectometry (OLCR) (Lenstar LS900; Haag Streit, Koniz, Switzerland), ultrasound pachymetry (US) (DGH Pachmate, DGH Technologies Inc, Exton, Pennsylvania, USA) and spectral-domain optical coherence tomography (OCT) (Spectralis OCT, Heidelberg Engineering, Hemel Hempstead Hertfordshire,United Kingdom).

Methods: The right eyes of 25 subjects were measured. Two independent observers took the measurements. Patients with previous corneal surgery or pathology were excluded. A series 5 scans were taken with OLCR and 25 with US and the average determined. With OCT 5 scans were taken and the best image was chosen for analysis.

Results: Mean central corneal thickness measurements were 541 micrometres (um) 38um (1 standard deviation) for OLCR, 568 38um for US and 567 38um for OCT. There was very strong correlation between the three measurement systems with R values of 0.88 between LCR and US, 0.89 between OCT and US and 0.93 between OLCR and OCT. There were no significant difference in thickness measurements between US and OCT but measurements were significantly less with OLCR compared to US and OCT (p 0.001).

Conclusions: There was very strong correlation between the three instruments but with mild, but statistically significant underestimation of central thickness with OLCR.