Ocular perfusion pressure and ophthalmic artery flow in patients with normal tension glaucoma

Abstract

BackgroundVascular insufficiency has been reported to be a cause of normal tension glaucoma (NTG). The aim of this study was to compare ocular perfusion pressure (OPP) and ophthalmic artery flow (OAF) between patients with NTG and those without glaucoma.MethodsWe considered one eye each from 31 NTG and 15 non-glaucoma control patients. Blood pressure and intraocular pressure (IOP) were measured in the sitting position, for calculation of OPP. Humphrey visual field (HVF) assessment was then carried out on NTG patients. All patients then underwent Transcranial Doppler ultrasound measurements of OAF parameters, including mean flow velocity (MFV), end diastolic velocity (EDV), peak systolic velocity (PSV) and resistive index (RI). We looked at differences in OPP and OAF parameters between the two groups, and their correlations in NTG patients. T-tests, χ2, ANOVA and Pearson Correlation tests were performed, with p < 0.05 considered statistically significant.ResultsThere were no statistically significant differences in OPP between the NTG and control groups (60.5+/-8.7 mmHg and 62.9+/-10.2 mmHg respectively, p = 0.393), and also no statistically significant differences in MFV, EDV, PSV and RI (all p > 0.05). In the NTG group, there were positive correlations between OPP and both MFV (r = 0.416, p = 0.020) and EDV (r = 0.369, p = 0.041). There were no statistically significant correlations between HVF mean deviation and OPP or OAF parameters (all p > 0.05).ConclusionThere is no difference in OPP and OAF parameters between patients with NTG and non-glaucoma controls, suggesting that vascular insufficiency or dysregulation by themselves may not account for the pathogenesis of NTG.

Ocular Perfusion Pressure and the Risk of Open-Angle Glaucoma: Systematic Review and Meta-analysis

“…Of these, 43 studies were finally included in the current systematic review and meta-analyses. Among them, 4 studies were population-based, cross-sectional studies 8,[22][23][24] and the others were hospital-based, clinical case-control studies 14, . These 43 studies included 3,009 patients with OAG (1,294 OAG, 926 POAG, and 789 NTG), 369 OHT patients, and 29,502 controls from 19 countries and their characteristics are summarized in the Table 1.…”

“…Second, several studies have suggested that NTG patients may have vascular dysregulation or weak www.nature.com/scientificreports www.nature.com/scientificreports/ vascular regulating system to defense against provocative stimulation. Thus, their vulnerability to vascular insults may not be revealed under normal (resting) condition 14,72 . All of the included studies measured OPP at resting and sitting position, and thus, our results could not reveal the OPP results in NTG patients under provocative stimulation.…”

Optical Coherence Tomography Angiography of the Peripapillary Retina in Primary Angle-Closure Glaucoma

“…These factors play a significant role in the development of damage in primary open-angle glaucoma (POAG), 3,5–10 especially in normal tension glaucoma (NTG). 11,12 Vascular factors may be involved in the pathogenesis of PACG and need further exploration.…”

Modern view on normal-tension glaucoma

“…Тем не менее другое недавнее исследование продемонстрировало противоположный результат: отсутствие статистически значимых различий в параметрах перфузионного давления и кровотока в глазной артерии у пациентов с ГНД и пациентов из группы контроля. Возможно, это указывает на то, что сосудистая недостаточность и дисрегуляция не играют решающей роли в патогенезе ГНД [28]. Противоречивость полученных данных свидетельствует, что точная роль сосудистого механизма на сегодняшний день еще неизвестна.…”