Purpose

To study the associations between optic nerve head (ONH) strains under intraocular pressure (IOP) elevation with retinal sensitivity in patients with glaucoma.

Design

Clinic-based cross-sectional study.

Participants

Two hundred twenty-nine patients with primary open-angle glaucoma (subdivided into 115 patients with high-tension glaucoma [HTG] and 114 patients with normal-tension glaucoma [NTG]).

Methods

For 1 eye of each patient, we imaged the ONH using spectral-domain OCT under the following conditions: (1) primary gaze and (2) primary gaze with acute IOP elevation (to approximately 35 mmHg) achieved through ophthalmodynamometry. A 3-dimensional strain-mapping algorithm was applied to quantify IOP-induced ONH tissue strain (i.e., deformation) in each ONH. Strains in the prelaminar tissue (PLT), the retina, the choroid, the sclera, and the lamina cribrosa (LC) were associated (using linear regression) with measures of retinal sensitivity from the 24-2 Humphrey visual field test (Carl Zeiss Meditec). This was performed globally, then locally according to a previously published regionalization scheme.

Main Outcome Measures

Associations between ONH strains and values of retinal sensitivity from visual field testing.

Results

For patients with HTG, we found (1) significant negative linear associations between ONH strains and retinal sensitivity (P < 0.001; on average, a 1% increase in ONH strains corresponded to a decrease in retinal sensitivity of 1.1 decibels [dB]), (2) that high-strain regions colocalized with anatomically mapped regions of high visual field loss, and (3) that the strongest negative associations were observed in the superior region and in the PLT. In contrast, for patients with NTG, no significant associations between strains and retinal sensitivity were observed except in the superotemporal region of the LC.

Conclusions

We found significant negative associations between IOP-induced ONH strains and retinal sensitivity in a relatively large glaucoma cohort. Specifically, patients with HTG who experienced higher ONH strains were more likely to exhibit lower retinal sensitivities. Interestingly, this trend in general was less pronounced in patients with NTG, which could suggest a distinct pathophysiologic relationship between the two glaucoma subtypes.

中文翻译：

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正常和高眼压青光眼患者视神经头应变与视野缺损之间的不同关联

目的

研究青光眼患者眼压 (IOP) 升高时视神经乳头 (ONH) 应变与视网膜敏感性之间的关系。

设计

基于临床的横断面研究。

参加者

229 名原发性开角型青光眼患者（细分为 115 名高眼压性青光眼 [HTG] 患者和 114 名正常眼压性青光眼 [NTG] 患者）。

方法

对于每位患者的一只眼睛，我们在以下条件下使用光谱域 OCT 对 ONH 进行成像：(1) 主要注视和 (2) 通过眼力测量法实现的急性 IOP 升高（至约 35 mmHg）的主要注视。应用 3 维应变映射算法来量化每个 ONH 中 IOP 诱导的 ONH 组织应变（即变形）。层前组织 (PLT)、视网膜、脉络膜、巩膜和筛板 (LC) 中的应变与 24-2 Humphrey 视野测试 (Carl Zeiss Meditec) 的视网膜敏感性测量相关联（使用线性回归） ). 这是在全球范围内执行的，然后根据先前发布的区域化方案在本地执行。

主要观察指标

ONH 菌株与视野测试的视网膜敏感性值之间的关联。

结果

对于 HTG 患者，我们发现 (1) ONH 应变与视网膜敏感性之间存在显着的负线性关联（P < 0.001；平均而言，ONH 应变增加 1% 对应于视网膜敏感性降低 1.1 分贝 [dB]）， (2) 高应变区域与高视野损失的解剖学映射区域共定位，以及 (3) 在上部区域和 PLT 中观察到最强的负相关。相反，对于 NTG 患者，除 LC 的颞上区域外，未观察到应变与视网膜敏感性之间存在显着关联。

结论

我们发现 IOP 诱导的 ONH 菌株与相对较大的青光眼队列中的视网膜敏感性之间存在显着的负相关。具体而言，经历过较高 ONH 应变的 HTG 患者更有可能表现出较低的视网膜敏感性。有趣的是，这种趋势在 NTG 患者中通常不太明显，这可能表明两种青光眼亚型之间存在明显的病理生理学关系。