Wachtl Josephine, Töteberg-Harms Marc, Frimmel Sonja, Roos Malgorzata, Kniestedt Christoph
Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland2Talacker Eye Center Zurich, Zurich, Switzerland.
Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland.
JAMA Ophthalmol. 2017 Jun 1;135(6):601-608. doi: 10.1001/jamaophthalmol.2017.1012.
Accurate determination of intraocular pressure (IOP) is crucial for the diagnosis and management of glaucoma. Objective clinical evaluation of the correction equations for Goldmann applanation tonometry (GAT) is lacking.
To investigate the difference between corrected and conventional GAT and Pascal dynamic contour tonometry (DCT) measurements, as well as the correlation between discordant IOP values and stage of glaucoma.
DESIGN, SETTING, AND PARTICIPANTS: This prospective cross-sectional case series was conducted at the Department of Ophthalmology, University Hospital Zurich, and Talacker Eye Center between July 1, 2011, and May 31, 2016, among 112 white patients with glaucoma.
Intraocular pressure measurements were performed with GAT and DCT in a randomized order. Goldmann applanation tonometry measurements were modified with 5 correction equations.
The primary end point was degree of concordance between corrected or uncorrected GAT and DCT measurements. The secondary end point was association between discordant IOP measurements and the stage of glaucoma, as assessed by the Glaucoma Severity Score.
Among the 112 patients (67 women and 45 men; mean [SD] age, 66.3 [13.1] years), 63 of the eyes in the study (56.3%) were left eyes and 85 patients (75.9%) were taking ocular antihypertensive medications. Mean (SD) IOP was 20.3 (4.5) mm Hg (95% CI, 19.4-21.1) as measured by DCT and 17.0 [4.1] mm Hg (95% CI, 16.3-17.8) as measured by GAT. The mean (SD) discordance between DCT and GAT measurements was -3.3 (2.0) mm Hg (95% CI, 2.9-3.6). The 5 corrected GAT values ranged from -2.7 to -5.4 mm Hg compared with DCT. The mean (SD) result of the Dresdner correction formula (17.6 [4.1] mm Hg) was closer to the DCT measurement than the original GAT measurement. The mean (SD) Glaucoma Severity Score was 4.7 (3.4) (95% CI, 4.1-5.4). The uncorrected discordance IOPDCT - IOPGAT showed a positive correlation with the Glaucoma Severity Score (rs = 0.33; P < .001) and a negative correlation with central corneal thickness (rs = -0.22; P = .02).
In comparison with DCT measurements, these data suggest that GAT values are significantly discordant in eyes with thin corneas and advanced glaucoma. Application of GAT-based correction formulas involves a possible risk of creating an even greater number of unpredictable measurement errors. Hence, we advise with caution, especially pertaining to eyes with thin corneas, to not place reliance on GAT readings, and abandon any correction formula.
clinicaltrials.gov Identifier: NCT01474070.
准确测定眼压（IOP）对于青光眼的诊断和管理至关重要。目前缺乏对戈德曼压平眼压计（GAT）校正公式的客观临床评估。
研究校正后的GAT与传统GAT以及帕斯卡动态轮廓眼压计（DCT）测量值之间的差异，以及眼压值不一致与青光眼分期之间的相关性。
设计、地点和参与者：这项前瞻性横断面病例系列研究于2011年7月1日至2016年5月31日在苏黎世大学医院眼科和塔拉克尔眼科中心进行，纳入了112例白人青光眼患者。
使用GAT和DCT以随机顺序测量眼压。戈德曼压平眼压计测量值用5种校正公式进行修正。
主要终点是校正或未校正的GAT与DCT测量值之间的一致性程度。次要终点是眼压测量值不一致与青光眼分期之间的关联，通过青光眼严重程度评分进行评估。
在112例患者（67例女性和45例男性；平均[标准差]年龄，66.3[13.1]岁）中，研究中的63只眼（56.3%）为左眼，85例患者（75.9%）正在使用眼部降压药物。DCT测量的平均（标准差）眼压为20.3（4.5）mmHg（95%置信区间，19.4 - 21.1），GAT测量的为17.0[4.1]mmHg（95%置信区间，16.3 - 17.8）。DCT与GAT测量值之间的平均（标准差）差异为 - 3.3（2.0）mmHg（95%置信区间，2.9 - 3.6）。与DCT相比，5种校正后的GAT值范围为 - 2.7至 - 5.4mmHg。德累斯顿校正公式的平均（标准差）结果（17.6[4.1]mmHg）比原始GAT测量值更接近DCT测量值。平均（标准差）青光眼严重程度评分为4.7（3.4）（95%置信区间，4.1 - 5.4）。未校正的眼压差异IOPDCT - IOPGAT与青光眼严重程度评分呈正相关（rs = 0.33；P <.001），与中央角膜厚度呈负相关（rs = - （续）0.22；P = 0.02）。
与DCT测量值相比，这些数据表明在角膜薄和青光眼晚期的眼中，GAT值存在显著差异。应用基于GAT的校正公式可能存在产生更多不可预测测量误差的风险。因此，我们谨慎建议，尤其是对于角膜薄的眼睛，不要依赖GAT读数，并放弃任何校正公式。
clinicaltrials.gov标识符：NCT01474070。
