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May 28, 2006
Pentacam Vs Ultrasound in corneal thickness measurment
Review Of Ophthalmology May 2006
In an independent study, researchers from Montreal and Paris say the Oculus Pentacam produces very accurate corneal thickness measurements when compared to ultrasonic pachymetry.The clinicians tested both eyes of 22 normal subjects. At one visit, an observer acquired three Pentacam elevation maps, then measured corneal thickness in nine different locations with ultrasonic pachymetry: central; superior; nasal-superior; nasal; nasal-inferior; inferior; temporal-inferior; temporal; and temporal-superior. They obtained three successive ultrasonic measurements in each location. At another visit, within one to six weeks of the first, two observers acquired three more Pentacam maps. The order of the visits, observers and eyes were all randomized.The researchers say that repeatability of the three successive measurements performed during the same visit ranged from substantial to almost perfect. The average intraclass correlation coefficient values, which measure the reliability/reproducibility of a measurement (with a value of 1 being perfect), were 0.94 for right eyes and 0.948 for left eyes. The lowest ICCs were obtained for the superior location measurements.Compared to ultrasound’s “true” values, the clinicians say the Pentacam’s accuracy was almost perfect for all locations. ICCs ranged from 0.863 to 0.993 with an average of 0.933 for OD and from 0.891 to 0.988 with an average of 0.936 for OS. Central pachymetries yielded the highest values.Researchers say that accuracy at this level means the Pentacam could be used in place of ultrasonic pachymetry
Posted by mehdi khanlari at May 28, 2006 11:40 PM