Copt R P, Thomas R, Mermoud A
Hôpital Ophtalmique Jules Gonin, University of Lausanne, Switzerland.
Arch Ophthalmol. 1999 Jan;117(1):14-6. doi: 10.1001/archopht.117.1.14.
To determine the effect of central corneal thickness (CCT) on the measurement of intraocular pressure (IOP) and on the resultant reclassification of patients as having primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), or ocular hypertension (OHT).
Intraocular pressure (Goldmann applanation tonomety) and CCT (ultrasound pachymetry) were measured in 22 patients with NTG, 49 with POAG, 44 with OHT and in 18 control subjects. The CCT was used to obtain a corrected value for the IOP and to reclassify the type of glaucoma.
There was no significant difference in CCT between controls (552 +/- 35 microns) and patients with POAG (543 +/- 35 microns), but the CCT in the group with NTG (521 +/- 31 microns) was significantly lower than that in the control group or the group with POAG (P < .001), and the CCT in the group with OHT (583 +/- 34 microns) was significantly higher than in controls or patients with POAG (P < .001). Correcting IOP for corneal thickness, 31% of the patients with NTG could be reclassified as having POAG, and 56% of the patients with OHT as normal.
Patients with NTG have a thinner CCT than do patients with POAG or controls. Underestimation of the IOP in patients with POAG who have thin corneas may lead to a misdiagnosis of NTG, while overestimation of the IOP in normal subjects who have thick corneas may lead to a misdiagnosis of OHT.
确定中央角膜厚度（CCT）对眼压（IOP）测量结果的影响，以及对原发性开角型青光眼（POAG）、正常眼压性青光眼（NTG）或高眼压症（OHT）患者最终重新分类的影响。
对22例NTG患者、49例POAG患者、44例OHT患者以及18名对照者进行眼压测量（Goldmann压平眼压计测量）和CCT测量（超声测厚仪测量）。利用CCT获得眼压的校正值，并对青光眼类型进行重新分类。
对照组（552±35微米）与POAG患者组（543±35微米）的CCT无显著差异，但NTG组（521±31微米）的CCT显著低于对照组或POAG组（P<.001），OHT组（583±34微米）的CCT显著高于对照组或POAG患者组（P<.001）。校正角膜厚度后的眼压显示，31%的NTG患者可重新分类为POAG，56%的OHT患者眼压正常。
NTG患者的CCT比POAG患者或对照者更薄。角膜薄的POAG患者眼压被低估可能导致NTG误诊，而角膜厚的正常受试者眼压被高估可能导致OHT误诊。
