Asan Kochkorov

Relationship between ocular pulse amplitude and systemic blood pressure measurements

Purpose:  This study aimed to determine whether ocular pulse amplitude (OPA) measured with dynamic contour tonometry (DCT) is related to systemic blood pressure (BP) parameters.

Choroidal Blood Flow Response to Isometric Exercise in Glaucoma Patients and Patients with Ocular Hypertension

PURPOSE To analyze submacular choroidal blood flow (ChBF) response to isometric exercise in untreated patients with glaucoma and ocular hypertension. METHODS ChBF was examined by means of confocal laser Doppler flowmetry during 5 minutes of baseline, during 90 seconds of isometric exercise with a Martins vigorimeter and during 15 minutes of recovery. Values from one randomly chosen eye of 45 healthy subjects, the eye with more advanced damage in 45 primary open-angle glaucoma (POAG) patients, and the eye with higher native intraocular pressure in 45 patients with ocular hypertension (OHT) were acquired, and parameters of ChBF as well as blood pressure response were analyzed. RESULTS Healthy eyes demonstrated higher ChBF at baseline than did the eyes in both the other groups (5126 ± 1487, 4186 ± 1011, and 4437 ± 1372 arbitrary units, ANOVA P = 0.003). Both mean and diastolic arterial blood pressures at baseline were lower in POAG patients than in those with OHT and healthy controls (P < 0.03); however, the response of mean blood pressure to isometric exercise was comparable across groups (P = 0.79). The ChBF response to exercise was stronger in the POAG group (ANOVA P = 0.02), it was twice as high as in the controls (+8.1% ± 8.0% vs. +3.7% ± 6.7%; P = 0.007) and borderline higher than in the OHT patients (+5.0% ± 8.0%; P = 0.051). CONCLUSIONS Baseline ChBF was lower in both the POAG and the OHT patients, compared with that in the controls. The stronger increase in ChBF in POAG patients in the face of an exercise-induced blood pressure increase indicates less active regulatory capacity in glaucoma patients.

Rigidity of retinal vessel in untreated eyes of normal tension primary open-angle glaucoma patients.

BackgroundTo analyze pulse wave propagation in the ocular circulation and vessel stiffness in untreated eyes of normal tension primary open-angle glaucoma (NTG) patients. MethodsInferotemporal retinal vessels of 22 NTG eyes and 25 controls were examined with a Retinal Vessel Analyzer. Inferotemporal peripapillary retinal nerve fiber layer thickness was measured by ocular coherence tomography. Phase delay between venous trough and arterial peak was assessed at 3 sites centrifugal from the disc and a choroid-to-retina pulse delay was calculated as an estimation of vessel rigidity. ResultsThere was choroid-to-retina pulse delay of 0.26±0.08, 0.30±0.11, and 0.33±0.11 seconds, respectively, in NTG eyes at proximal, middle, and distal sites; in control eyes, the corresponding values were 0.28±0.10, 0.35±0.12, and 0.40±0.17 seconds. Average choroid-to-retina pulse delay was shorter in NTG eyes (P=0.028). Retinal nerve fiber layer (inferotemporal) showed an opposite correlation with choroid-to-retina pulse delay in controls (r=−0.48, P=0.019) and in NTG eyes (r=0.47, P=0.032 ). ConclusionsUntreated NTG eyes show stiffer retinal vessels. Vessel rigidity correlates with level of glaucomatous damage.

Influence of gender and menopausal status on peripheral and choroidal circulation

Acta Ophthalmol. 2010: 88: 850–853

Association between risk factors and glaucomatous damage in untreated primary open-angle glaucoma.

Purpose:To analyze an association between the presumed risk factors for glaucoma and the actual extent of glaucomatous damage in untreated primary open-angle glaucoma. Patients and Methods:In 50 untreated open-angle glaucoma patients, we analyzed an association between the level of glaucomatous damage and presumed glaucoma risk factors: mean untreated intraocular pressure (IOP) and short-term IOP variability, ocular pulse amplitude, corneal thickness, acral and corneal temperature, retinal arterial diameter and retinal venous diameter, choroidal blood flow (laser Doppler flowmetry flow, velocity, volume), heart rate, and ocular perfusion pressure. Morphologic damage (mean retinal nerve fiber layer thickness, measured by ocular coherence tomography) and functional damage (visual field mean defect) were evaluated separately in 2 forward-stepwise multiple regression models. Results:The mean retinal nerve fiber layer thickness was significantly (P<0.05) associated with IOP (r=−0.35), retinal arterial diameter (r=0.36), and choroidal blood flow (r=0.30); mean defect was associated with ocular perfusion pressure (r=−0.30), laser Doppler flowmetry volume (r=−0.33), and IOP variability (0.36). Conclusions:Despite small differences between the morphologic and functional glaucomatous damage, IOP and perfusion parameters seem to contribute, at least in part, independently to both.

The prognostic value of retinal vessel analysis in primary open-angle glaucoma.

To analyse a prognostic value of initial retinal vessel flicker response for the 3‐year development of functional (visual field) and morphological (nerve fibre layer thickness) damage progression in primary open‐angle glaucoma patients.