Pulsatile ocular blood flow in patients with pseudoexfoliation

Evaluation of choroidal thickness using enhanced depth imaging by spectral-domain optical coherence tomography in patients with pseudoexfoliation syndrome

PURPOSE

To investigate the choroidal thickness using optical coherence tomography in the eyes of patients with unilateral and bilateral pseudoexfoliation syndrome and to compare them with healthy controls.

METHODS

We studied four groups: (1) affected eyes from 30 patients with unilateral PEX syndrome affecting the right eye of 17 patients and the left eye of 13 patients; (2) clinically unaffected eyes of 30 patients with unilateral PEX syndrome; (3) the eyes of 30 patients with bilateral PEX syndrome; and (4) the eyes of 30 normal healthy subjects. Choroidal thickness was evaluated using high-speed, high-resolution enhanced depth imaging by spectral-domain optical coherence tomography. Optical coherence tomography features were compared in all groups using the statistical package SPSS v 15.0.

RESULTS

The mean subfoveal choroidal thicknesses were 237.35±58.01 μm in group 1; 330.75±47.84 μm in group 2; 206.3±86.75 μm in group 3; and 311.8±51.42 μm in group 4. Significant differences in the mean subfoveal choroidal thickness were found between groups 1 and 2 (P<0.001), groups 1 and 4 (P=0.004), groups 2 and 3 (P<0.001), and groups 3 and 4 (P<0.001).

CONCLUSION

In this study, it was observed that clinically affected eyes of patients with PEX syndrome have significantly thinner choroids compared with the clinically unaffected eyes of patients with unilateral PEX syndrome and eyes of healthy controls.

Dynamic contour tonometry in primary open angle glaucoma and pseudoexfoliation glaucoma: factors associated with intraocular pressure and ocular pulse amplitude

Purpose:

To compare the intraocular pressures (IOP) and ocular pulse amplitudes (OPAs) in patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG), and to evaluate ocular and systemic factors associated with the OPA.

Materials and Methods:

In this prospective study, on 28 POAG and 30 PXG patients, IOP was measured with the Goldmann applanation tonometry (GAT) and the Pascal dynamic contour tonometry (DCT). Other measurements included central corneal thickness (CCT), vertical cup-to-disc ratio (CDR), and systolic and diastolic blood pressure. Statistical significance was defined as P < 0.05.

Results:

In each of the POAG and PXG groups, GAT IOP was correlated with CCT (r = 0.40, P = 0.03 and r = 0.35, P = 0.05, respectively), whereas DCT IOP and CCT were not correlated. In all patients and in the POAG group, OPA was positively correlated with DCT IOP (r = 0.39, P = 0.002). OPA was not correlated with CCT in the POAG (P = 0.80), nor in the PXG (P = 0.20) group, after adjusting for DCT IOP. When corrected for DCT IOP and CCT, there was a significant negative correlation between OPA and vertical CDR in all patients (r = −0.41, P = 0.002). There was no significant difference in OPA between groups (P = 0.55), even when OPA was adjusted for IOP and systolic and diastolic pressure (P = 0.40), in a linear regression model.

Conclusion:

DCT IOP and OPA are not correlated with CCT. There is no significant difference between the OPA of PXG and POAG eyes. OPA is correlated with DCT IOP, and is lower in eyes with more advanced glaucomatous cupping.

Frequency of systemic vascular diseases in patients with primary open-angle glaucoma and exfoliation glaucoma

PURPOSE

Abnormal fibrils can be identified by electron microscopy in the heart, lung, liver, kidney, cerebral meninges and other tissues of patients with exfoliation syndrome (ES). However, a clinical association of ES with arterial hypertension (HT), ischaemic heart disease (IHD), cerebrovascular accidents and aneurysm of the abdominal aorta is debated. We conducted a national registry-based survey to further assess the first two of these associations.

METHODS

We reviewed the records of 519 consecutive patients to whom the Social Insurance Institution of Finland had granted free medication for glaucoma according to national common criteria. The glaucoma was classified either as primary open-angle glaucoma (POAG) or exfoliation glaucoma (EG), masked to any systemic diseases; 20 patients with other types of glaucoma were excluded from the survey. Masked to the type of glaucoma, the registry provided data on free medication similarly granted for HT, IHD and diabetes mellitus (DM), a known modifier of risk for cardiovascular disease. Data were analysed by logistic regression, modelling age, gender and DM as confounders.

RESULTS

The control group of 344 patients with POAG was comparable as regards gender with the study group of 155 patients with EG, but patients with POAG were both younger (mean 69 versus 73 years; P < 0.0001) and had DM twice as often (10% versus 5%; P = 0.05) compared to those with EG. Adjusting for age, gender and presence of DM, no difference in frequency of HT [odds ratio (OR) 0.80 for presence of EG; 95% confidence interval (CI) 0.52-1.23, P = 0.31] or IHD (OR 0.86 for presence of EG; 95% CI 0.49-1.13, P = 0.66) was detected between the two groups.

CONCLUSION

In this population-based registry survey, no difference in frequency of HT or IHD was noted between patients with POAG and EG who had been granted free medication for these chronic diseases according to national common criteria. The frequency of DM was lower among patients with EG, in line with several previous reports.

In vivo dynamic human retinal blood flow imaging using ultra-high-speed spectral domain optical coherence tomography

An ultra-high-speed spectral domain optical Doppler tomography (SD-ODT) system is used to acquire images of blood flow in a human retina in vivo, at 29,000 depth profiles (A-lines) per second and with data acquisition over 99% of the measurement time. The phase stability of the system is examined and image processing algorithms are presented that allow accurate determination of bi-directional Doppler shifts. Movies are presented of human retinal flow acquired at 29 frames per second with 1000 A-lines per frame over a time period of 3.28 seconds, showing accurate determination of vessel boundaries and time-dependent bi-directional flow dynamics in artery-vein pairs. The ultra-high-speed SD-ODT system allows visualization of the pulsatile nature of retinal blood flow, detects blood flow within the choroid and retinal capillaries, and provides information on the cardiac cycle. In summary, accurate video rate imaging of retinal blood flow dynamics is demonstrated at ocular exposure levels below 600 microW.