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J.A. Duran, I.R. Agirretxe, Jr., A. Acera; Measurement of Central Corneal Thickness With Ultrasound, Orbscan and Optical Coherence Tomography in Ocular Hypertension . Invest. Ophthalmol. Vis. Sci. 2006;47(13):1337.
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© ARVO (1962-2015); The Authors (2016-present)
To compare central corneal thickness (CCT) measurements using ultrasonic pachymetry (US), Orbscan slit–scanning topography (ORB) and optical coherence tomography (OCT) in ocular hypertension (OHT).
CCT was measured in 50 eyes from 29 patients with OHT. OHT was defined as intraocular pressure (IOP) > 21 mmHg, normal optic disc and normal visual fields (Humprey SITA standard 24/2). Measurements were performed in the morning, within 2 hours of each other to minimize diurnal variations, with US (Tomey SP 2000), ORB (Orbscan II) and OCT (OCT3). Statistical comparisons were carried out with ANOVA test for repeated measurements. Concordance between instruments was analysed with intraclass correlation coefficients (ICC). Correlation between IOP and CCT was studied by Pearson coefficient. P < 0.05 was considered statistically significant
There were differences between instruments in measurement of CCT (US: 573.42 ± 35.3 µm; ORB: 583.98 ± 37.4; OCT: 564.15 ± 37.9; P<0.001 ANOVA). ORB was significantly higher than US and OCT (P<0.001, contrast analysis). There were no differences between US–OCT (P=0.42, contrast analysis). Concordance between instruments was high (ICC US–ORB: 0.9; ICC US–OCT: 0.91; ICC ORB–OCT: 0.88; P<0.001). There were no correlation between IOP–US (r=–0.18; P=0.2) and a weak negative correlation between IOP–ORB (r=–0.34; P=0.01) and IOP–OCT (r=–0.33; P=0.03).
There are no differences between US and OCT pachymetry in OHT patients. In contrast ORB measurements are higher than those made using US or OCT. There is a high concordance between instruments in CCT determination. In OHT patients there is no positive correlation between IOP and CCT.
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