Ophthalmic Engineering & Innovation Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore.
Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.
Invest Ophthalmol Vis Sci. 2018 Jan 1;59(1):260-272. doi: 10.1167/iovs.17-21982.
To compare in vivo lamina cribrosa (LC) strains (deformations) following acute IOP elevation in healthy, glaucoma, and ocular hypertensive subjects.
There were 20 healthy, 20 high-tension primary open-angle glaucoma (POAG), 16 primary angle-closure glaucoma (PACG), and 20 ocular hypertensive (OHT; with normal visual fields) eyes studied. For each test eye, the optic nerve head was imaged three times (at baseline IOP, following an acute elevation of IOP to approximately 35 then 45 mm Hg using an ophthalmodynamomter) using optical coherence tomography (OCT). A three-dimensional (3D) strain-mapping algorithm was applied to both sets of baseline and IOP-elevated OCT volumes to extract IOP-induced 3D strains. Octant-wise LC strains were also extracted to study the pattern of local deformation.
The average LC strain in OHT subjects (3.96%) was significantly lower than that measured in healthy subjects (6.81%; P < 0.05). On average, POAG subjects experienced higher strain than the PACG subjects (4.05%), healthy subjects experienced higher strains than the POAG and PACG subjects, but these difference were not statistically significant. Local LC deformations showed lowest strain in the infero-temporal and temporal octant in the POAG and OHT subjects.
We demonstrate measurable LC strains in vivo in humans as a response to acute IOP elevation. In this population, our data suggest that OHT LCs experience lower IOP-induced strains than healthy LCs.
比较健康人、青光眼和高眼压人群急性眼压升高后活体视盘筛板（LC）的应变（变形）。
研究对象包括 20 名健康人、20 名高眼压原发性开角型青光眼（POAG）患者、16 名原发性闭角型青光眼（PACG）患者和 20 名高眼压（OHT；视野正常）患者。对于每只测试眼，使用光学相干断层扫描（OCT）在基线眼压（IOP）、使用眼压计将IOP 升高至约 35 然后 45mmHg 后，对视盘进行三次成像。将三维（3D）应变映射算法应用于两组基线和IOP 升高的 OCT 体积，以提取IOP 诱导的 3D 应变。还提取了八角形 LC 应变，以研究局部变形的模式。
OHT 受试者的平均 LC 应变（3.96%）明显低于健康受试者（6.81%；P<0.05）。平均而言，POAG 患者的应变高于 PACG 患者（4.05%），健康受试者的应变高于 POAG 和 PACG 患者，但这些差异无统计学意义。POAG 和 OHT 受试者的下颞和颞八角区的 LC 变形显示出最低的应变。
我们证明了人类活体 LC 在急性眼压升高时会产生可测量的应变。在该人群中，我们的数据表明，OHT 的 LC 经历的 IOP 诱导应变低于健康的 LC。
