Comparison of Central Corneal Thickness and Anterior Chamber Depth Measured Using Three Different Devices

PURPOSE: To compare measurements of central corneal thickness (CCT) and anterior chamber depth (ACD) obtained using Galilei(TM), Pentacam(R) (Oculus, Wetzlar, Germany) and Lenstar(R) (Haag-Streit, Koeniz, Switzerland) and analyze the measurement agreements. METHODS: CCT and ACD were measured using Galilei(TM), Pentacam(R) and Lenstar(R) in 47 eyes of 25 healthy subjects. The measurements were compared among the 3 devices. RESULTS: The average CCT measurements using Galilei(TM), Pentacam(R) and Lenstar(R) were 552.6 +/- 29.41 microm, 543.9 +/- 30.50 microm and 537.5 +/- 30.26 microm, respectively. The measurements significantly correlated with each other (r > 0.9, p 0.9, p < 0.001), but were statistically significantly different (p = 0.034). The CCT 95% limits of agreement (LoA) between Galilei(TM) and Pentacam(R), Pentacam(R) and Lenstar(R) and Lenstar(R) and Galilei(TM) were 31.95 microm, 44.76 microm and 46.57 microm, respectively and 95% ACD LoA were 0.46 mm, 0.32 mm and 0.28 mm, respectively. CONCLUSIONS: CCT and ACD measured using the 3 devices were highly correlated with each other but the measurements were statistically different. Therefore, the measurements were not interchangeable and these differences should be considered in clinical use.

Comparison of Anterior Segment Measurements Using Scanning-Slit Topography and Optical Low-Coherence Reflectometry (OLCR) Biometry

PURPOSE: To compare the results of anterior segment biometry including white-to-white (WTW) between scanning-slit topography (ORBscan IIz(R), Bausch & Lomb), optical low-coherence reflectometry (OLCR) biometry (Lenstar(R), Haag-Streit), and Castroviejo calipers. METHODS: Measurements on 72 eyes of 36 patients that underwent refractive surgery were measured using ORBscan(R), Lenstar(R), and calipers and compared. Ocular biometry parameters used in this study included the WTW, central corneal thickness, anterior chamber depth (ACD), keratometry, and pupil size. RESULTS: The WTW measurements using ORBscan(R) and calipers (11.57 +/- 0.35 mm and 11.58 +/- 0.34 mm, respectively) were statistically similar. However, the measurement using Lenstar(R) (12.05 +/- 0.40 mm) was significantly greater than with the other methods (p < 0.001). Central corneal thickness and keratometry measurements using ORBscan(R) were greater than when using Lenstar(R) (p = 0.01 for both). ACD and pupil size measurement using Lenstar(R) were greater than when using ORBscan(R) (p < 0.001 for both). CONCLUSIONS: Because WTW and ACD measurements using Lenstar(R) were greater than when using ORBscan(R) and calipers, unexpected high-vaulting may be observed due to the selection of a larger-sized posterior chamber phakic intraocular lens. Therefore, the differences in measurements obtained when using these methods should be considered.

Comparison of Anterior Segment Measurements Using Scanning-Slit Topography and Optical Low-Coherence Reflectometry (OLCR) Biometry

PURPOSE: To compare the results of anterior segment biometry including white-to-white (WTW) between scanning-slit topography (ORBscan IIz(R), Bausch & Lomb), optical low-coherence reflectometry (OLCR) biometry (Lenstar(R), Haag-Streit), and Castroviejo calipers. METHODS: Measurements on 72 eyes of 36 patients that underwent refractive surgery were measured using ORBscan(R), Lenstar(R), and calipers and compared. Ocular biometry parameters used in this study included the WTW, central corneal thickness, anterior chamber depth (ACD), keratometry, and pupil size. RESULTS: The WTW measurements using ORBscan(R) and calipers (11.57 +/- 0.35 mm and 11.58 +/- 0.34 mm, respectively) were statistically similar. However, the measurement using Lenstar(R) (12.05 +/- 0.40 mm) was significantly greater than with the other methods (p < 0.001). Central corneal thickness and keratometry measurements using ORBscan(R) were greater than when using Lenstar(R) (p = 0.01 for both). ACD and pupil size measurement using Lenstar(R) were greater than when using ORBscan(R) (p < 0.001 for both). CONCLUSIONS: Because WTW and ACD measurements using Lenstar(R) were greater than when using ORBscan(R) and calipers, unexpected high-vaulting may be observed due to the selection of a larger-sized posterior chamber phakic intraocular lens. Therefore, the differences in measurements obtained when using these methods should be considered.

Comparison of Ocular Biometry Measured by Ultrasound and Two Kinds of Partial Coherence Interferometers

PURPOSE: To evaluate the reproducibility and repeatibility of biometry in cataractous eyes, pseudophakic eyes and eyes having undergone refractive surgery. The OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments were compared, as were. The accuracies of the refractive results after cataract surgery. METHODS: The biometries of 45 cataractous eyes, 31 pseudophakic eyes, and 32 eyes having undergone refractive surgery were measured by two practitioners using OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) instruments. The paired t-test was used to compare the reproducibilities in the three groups. RESULTS: There were no differences in axial length among the groups when using any of the instruments. There was no significant difference in the repeatibility regardless of the instrument used, although. In the cataractous eyes, pseudophakic eyes and eyes with refractive surgery, OcuScan(R)RxP showed the highest repeatability. However, we knew that all three instruments were excellent in the repeatability because the difference was less than 1.5%. The Prediction error of the instruments with regard to refractive results could not be determined after cataract surgery. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments. CONCLUSIONS: In all groups, OcuScan(R)RxP, LENSTAR(R) and IOL Master(R) showed no significant differences with regard to reproducibility or prediction of refractive power after surgery. Among three groups, the repeatability was rather high in the existing ultrasound method than in the partial coherence interferometers. In some patients with severe cataract, measurement was impossible for both the LENSTAR(R) and IOL Master(R) instruments.