Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
Department of Ophthalmology, Military Institute of Medicine, ul. Szaserów 128, 04-141, Warsaw, Poland.
Graefes Arch Clin Exp Ophthalmol. 2019 Nov;257(11):2449-2459. doi: 10.1007/s00417-019-04433-9. Epub 2019 Aug 3.
To ascertain whether changes in the spectral content of the corneal pulse (CP) signal, measured in vivo in primary open-angle glaucoma (POAG) patients, indirectly reflect changes in corneal biomechanics after canaloplasty.
Fifteen eyes of 15 POAG patients who underwent canaloplasty combined with phacoemulsification were enrolled. Standard ophthalmic examinations were conducted before washout, pre-operatively, at days 1, 7, and 1, 3, 6, and 12 months after surgery. Non-contact measurements of the CP signal were performed at pre-washout, pre-operatively, and at 3, 6, and 12 months post-operatively. Then, amplitudes of the CP first five harmonics associated with the heart rate were estimated. Temporal changes of all considered parameters were tested at a Bonferroni-adjusted significance level set to 0.005.
A decrease in the amplitude of the first harmonic and an increase in the normalized amplitude of the third harmonic (A) of the CP signal were noticed between the pre-washout and the pre-operative stages (p = 0.003 and p = 0.004, respectively). This corresponds to an increase in median intraocular pressure (IOP) values by 6.0 mmHg (p = 0.0045). After surgery, A reached the highest value at 3 months post-operatively, compared with pre-washout level (p = 0.0045).
Alterations in corneoscleral stiffness caused by surgery are reflected in changes in the A value. Hence, post-operative corneal biomechanics could be monitored indirectly by this supporting indicator that can be used to estimate the time at which measures of IOP are no longer biased by the changed cornea boundary conditions caused by canaloplasty.
NCT02908633.
确定原发性开角型青光眼（POAG）患者活体测量的角膜脉冲（CP）信号光谱内容的变化是否间接反映了小梁成形术后角膜生物力学的变化。
纳入 15 例接受小梁成形术联合超声乳化术的 POAG 患者的 15 只眼。在冲洗前、术前、术后第 1、7、1、3、6 和 12 个月进行标准眼科检查。在冲洗前、术前以及术后第 3、6 和 12 个月进行非接触式 CP 信号测量。然后，估计与心率相关的 CP 前五个谐波的幅度。在 Bonferroni 调整的显著性水平（设定为 0.005）下测试所有考虑参数的时间变化。
CP 信号的第一谐波幅度降低，第三谐波（A）的归一化幅度增加，这是在冲洗前和术前阶段观察到的（p=0.003 和 p=0.004）。这对应于眼内压（IOP）中位数升高 6.0mmHg（p=0.0045）。手术后，A 在术后 3 个月达到最高值，与冲洗前水平相比（p=0.0045）。
手术引起的角巩膜刚度变化反映在 A 值的变化中。因此，术后角膜生物力学可以通过这个支持性指标间接监测，该指标可用于估计 IOP 测量值不再受小梁成形术引起的角膜边界条件变化影响的时间。
NCT02908633。
