Olga Furashova

Central retinal venous pulsation pressure in different stages of primary open-angle glaucoma

Background To evaluate the central retinal venous pulsation pressure (CRVPP) in patients with intraocular pressure (IOP)-controlled early, moderate and advanced open-angle glaucoma and a healthy control group. Methods CRVPP was measured with a contact lens dynamometer calibrated in mm Hg (Meditron GmbH, Voelklingen, Germany) in 34 patients with IOP-controlled open-angle glaucoma who were selected consecutively and according to the stage of their visual fields and 27 age-matched healthy controls. If a spontaneous venous pulsation was seen, CRVPP was considered to be equal to IOP. Visual fields were tested with the Humphrey 30-2 SST programme. The ocular perfusion pressure was conventionally calculated as OPP1=2/3MAP − IOP (MAP=systemic mean arterial blood pressure) and, using the measured CRVPP in the formula, as OPP2=2/3MAP − CRVPP. Statistical analysis was performed using the Kruskal–Wallis and the Mann–Whitney U test. Results Median CRVPP was 14.0 mm Hg (IQR 12.0–16.0) in controls, 15.0 mm Hg (IQR 14.0–17.0) in early, 38.9 mm Hg (IQR 29.9–48.4) in moderate and 34.6 mm Hg (IQR 23.9–51.0) in advanced glaucoma cases. The conventionally calculated OPP1 was 49.8 mm Hg (IQR 42.7–57.6) for controls, 56.9 mm Hg (IQR 55.3–58.8) for early, 56.6 mm Hg (IQR 51.2–64.4) for moderate and 59.3 mm Hg (IQR 53.9–61.6) for advanced cases. OPP2 was equal to OPP1 in the control group, 56.1 mm Hg (IQR 54.5–57.9) in early, 25.1 mm Hg (IQR 15.7–38.6) and 34.2 mm Hg (IQR 20.4–47.5) in moderate and advanced cases. This difference was statistically significant for moderate (OPP2 lower; p=0.003) and advanced (OPP2 lower; p=0.002) cases. Conclusions In more advanced cases of glaucoma, CRVPP seems to be much higher than previously thought. This might further compromise the perfusion pressure in the prelaminar region of the optic nerve head and be of clinical importance, especially in IOP-controlled more advanced cases. This should be considered as a possible risk factor for progression. Trial registration number ClinicalTrials.gov ID: NCT01503996.

Nocturnal blood pressure in primary open-angle glaucoma

To evaluate the nocturnal blood pressure (BP) dipping‐pattern in patients with manifest primary open‐angle glaucoma (POAG) and to find possible associations with the severity of visual field damage.

Comparison of Normal- and High-Tension Glaucoma: Nerve Fiber Layer and Optic Nerve Head Damage

Purpose: The aim of this study was to investigate differences in the nerve fiber layer and glaucoma-induced structural optic nerve head (ONH) damage in patients with normal- (NTG) and high-tension (HTG) glaucoma. Methods: In this retrospective pair-matched comparative study, 22 NTG and 22 HTG eyes were matched according to the same glaucomatous damage based on rim volume, rim area and disk size, as measured by Heidelberg retinal tomography (HRT III). Visual fields (VF) were assessed by Humphrey perimetry, and nerve fiber layer thickness was determined both by scanning laser polarimetry (GDxVCC) and spectral-domain optical coherence tomography (SD-OCT). Comparisons of all measured parameters were made between NTG and HTG groups. Results: Based on HRT results, both NTG and HTG eyes displayed comparable structural damage to the ONH (NTG/HTG, mean: disk area, 2.30/2.31 mm2, p = 0.942; rim area, 1.02/0.86 mm2, p = 0.082; rim volume, 0.19/0.17 mm3, p = 0.398). NTG eyes had significantly less VF damage than HTG eyes (NTG/HTG, mean deviation: -4.23/-12.12 dB, p = 0.002; pattern standard deviation: 5.39/8.23 dB, p = 0.022). The inferior nerve fiber layer of NTG patients was significantly thicker than that of HTG patients (NTG/HTG, mean: GDx inferior: 53.5/46.3 µm, p = 0.046). SD-OCT revealed a significantly thicker nerve fiber in NTG compared with HTG patients in all quadrants (NTG/HTG, total mean: 72.72/58.45 µm, p = 0.002). Conclusion: At comparable glaucomatous stages, nerve fiber loss was more advanced in HTG patients compared with NTG patients.

Retinal Changes in Different Grades of Retinal Artery Occlusion: An Optical Coherence Tomography Study

Purpose To investigate layer-by-layer changes in retinal thickness and reflectivity regarding the severity grade of acute retinal artery occlusion (RAO) using spectral-domain optical coherence tomography (SD-OCT). Methods This study is a retrospective, observational case-control series that took place in an institutional setting and included 148 eyes from 74 patients diagnosed with acute RAO (central or branch). SD-OCT examinations were taken at baseline. Based on OCT findings, RAO was categorized into three grades (incomplete, subtotal, total). The thickness and reflectivity of selected retinal layers were measured from SD-OCT images. The data were compared across the three grades and against the contralateral eyes (controls). The main outcome measures were thickness and reflectivity of selected retinal layers. Results The thickness of the inner and middle retinal layers differed significantly across the three RAO groups (P < 0.001), whereas the outer retinal layer thickness remained not significantly different. Reflectivity values showed statistically significant differences in the inner, middle, and outer retinal layers, but not in the vitreous body (P < 0.001). Conclusions The reflectivity changes of selected retinal layers differ significantly regarding different grades of RAO. SD-OCT reflectivity measurement may be used as a noninvasive method to estimate the grade of retinal ischemia in RAO.