Comparison of methods of central corneal thickness measurement in glaucoma
Reviewed by Jayavani Myneni

This prospective study was done to compare the accuracy and reproducibility of central corneal thickness measured by hand-held and disc-mounted ultrasound pachymeter in glaucoma patients. Sixty-five patients were included in the study. Patients with corneal diseases, corneal astigmatism >3 diopters or history of laser or intraocular surgery within the previous three months were excluded from the study. The hand-held pachymeter used was PachPen (Accutome) and desk-mounted pachymeter was PacScan (Sonomed). Three measurements were obtained with each instrument to minimise error and with both instruments within five minutes of each other to avoid possible diurnal variations. The mean central corneal thickness (CCT) was 526.5±44.8µ and 530.0±44.7µ in hand-held and desk-mounted pachymeters respectively. The mean difference between the measurements in eyes by the different techniques was 3.22 with 2SD=9.52µ. Both instruments showed high intraobserver correlation: 0.972 for hand-held pachymeter and 0.993 for the desk-mounted pachymeter. The limitations of this study were that the interobserver variability was not measured and the sample size was small.

Comparison of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeters in glaucoma patients.
Salim S, Du H, Wan J.
SEMINARS IN OPHTHALMOLOGY
2015;30(4):268-71.