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Abstract
Purpose
We compared the measurements of corneal thickness and anterior chamber depth (ACD) using three different methods Orbscan, Pentacam and ultrasound pachymetry.
Methods
In healthy volunteers, central corneal thickness was measured with Orbscan, Pentacam and ultrasound pachymetry. Estimation of peripheral corneal thickness and ACD were done by Orbscan and Pentacam. All results were compared statistically.
Results
The mean central corneal thickness of 64 eyes measured by Orbscan, Pentacam and ultrasound pachymetry were 509.1±61.0 μ m, 539.2±51.7 μ m and 527.4±48.3 μ m, respectively. There were statistically significant differences in the results among the three methods (repeated-measures analysis of variance (ANOVA), p<0.05). There were significant correlations between the ultrasonic pachymetry, the Orbscan and the Pentacam (Pearson correlation, r >0.90, p<0.05). The temporal and nasal peripheral corneal thicknesses were thinner in the Pentacam than in the Orbscan (paired t-test, p<0.05). The superior and inferior corneal thickness and ACD were not significantly different.
References
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Figure 1.
The correlation plot of the central corneal thickness (CCT) measured by Ultrasound pachymetry (US), Orbscan (ORB) and Pentacam (in μm). (A) US CCT and ORB CCT (r=0.968, p=0.000), (B) US CCT and Pentacam CCT (r=0.927, p=0.000), (C) Pentacam CCT and ORB CCT (r=0.965, p=0.000).
Figure 2.
The correlation plot of the anterior chamber depth (ACD, in mm) measured by Orbscan (Orb) and Pentacam (r=0.67, p<0.05)
Table 1.
The central corneal thickness (m) measured by Ultrasound pachymetry (Ultrasound), Orbscan and Pentacam (Mean± standard deviation)
| | Ultrasound | Orbscan | Pentacam | p value* |
|---|---|---|---|---|
| CCT† (m) | 527.4±48.3 | 509.1±61.0 | 539.4±51.7 | 0.000 |
Table 2.
The comparison of corneal thickness (means± standard deviation) between Orbscan and Pentacam
| |
Corneal thickness |
||
|---|---|---|---|
| Orbscan (μm) | Pentacam (μm) | p value* | |
| Center | 515.94±56.75 | 544.51±47.89 | 0.00 |
| Thinnest | 510.16±58.07 | 540.69±49.54 | 0.00 |
| Temporal | 582.21±35.90 | 573.14±35.90 | 0.01 |
| Nasal | 613.43±43.46 | 593.90±49.75 | 0.00 |
| Superior | 613.67±40.84 | 586.96±41.24 | 0.93 |
| Inferior | 586.96±41.24 | 580.49±42.56 | 0.05 |
Table 3.
The comparison of anterior chamber depth (means± standard deviation) between Orbscan and Pentacam
| |
Anterior chamber depth |
||
|---|---|---|---|
| Orbscan (mm) | Pentacam (mm) | p value* | |
| Center | 3.15±0.40 | 3.24±0.51 | 0.09 |
| Deepest | 3.25±0.40 | 3.34±0.55 | 0.13 |
| Temporal | 2.93±0.32 | 2.90±0.33 | 0.30 |
| Nasal | 2.58±0.41 | 2.59±0.41 | 0.88 |
| Superior | 2.74±0.37 | 2.69±0.47 | 0.30 |
| Inferior | 2.93±0.39 | 3.02±0.33 | 0.13 |
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