J Korean Ophthalmol Soc.  2002 Jan;43(1):17-22.

The Effects of Dry Eye on the Corneal Thickness Measured by Orbscan and Ultrasonic Pachymetry

• Han YS
• Ahn JH
• Lew HM

Abstract

PURPOSE: To evaluate the effect of dry eye on the corneal thickness measured by Orbscan and ultrasonic pachymetry.
METHODS
The central corneal thickness was measured by both ultrasonic and Orbscan pachymetry in 30 eyes with dry eye (dry eye group) and in 30 eyes of normal subjects (control group). Dry eye was diagnosed when a Schirmer test result was less than 10 mm (after topical anesthesia) and the test for tear osmolarity was also performed.
RESULTS
Tear osmolarity was 364.4+/-42.9 mOsm/L in dry eye group and 337.8+/-34.5 mOsm/L in control group. It was significantly higher in dry eye group than in the control group (p=0.011). Mean central corneal thickness measured by Orbscan pachymetry was 547.5+/-27.3 microgram in dry eye group and 562.0+/-20.4 microgram in the control group. It was significantly thinner in dry eye group than in the control group (p=0.023). Mean central corneal thickness measured by ultrasonic pachymetry was 535.7+/-27.2 microgram in dry eye group and 547.6+/-20.1 microgram in the control group with out significant difference between the two groups (p=0.059).
CONCLUSIONS
The corneal thickness measured by ultrasonic pachymetry is less affected by dry eye compared to that measured by Orbscan pachymetry.

Keyword

Central corneal thickness; Dry eye; Orbscan; Ultrasonic pachymetry

MeSH Terms

Osmolar Concentration
Ultrasonics*