Ocular Pulse Amplitude Values Research Articles

Evaluation of eye health in children with type 1 diabetes mellitus and celiac disease.

Pediatric celiac disease (CeD) and type 1 diabetes mellitus (T1DM) have well established effects on eye health but comorbid effect is not known. To evaluate the eye health of children with T1DM and CeD to predict microvascular retinal pathologies by diagnosis of probable intraocular pressure increase which is an important glaucoma trigger. In this case-controlled study, 28 eyes of 14 children both T1DM and CeD, with a mean age of 12.6 ± 3.9 years, and 28 eyes of gender-matched 14 healthy children as a control group were included. In both groups, detailed ocular examinations and measurement of intraocular pressure (IOP), ocular pulse amplitude (OPA), thicknesses of ganglion cell layer (GCL), inner plexiform layer (IPL), retinal nerve fiber layer (RNFL), and choroid thicknesses (CT) were done. All the patients with T1DM and CeD were newly diagnosed. The evaluations of IOP and OPA were made using a Pascal dynamic tonometer and thicknesses measured by optical coherence tomography. The IOP and OPA values of the patient group were found to be statistically significantly higher than those of the control group (17.1 and 1.86 vs 14.78 and 1.57 mmHg, P <.0001, P <.001, respectively). IOP values of all patients were higher than IOP cut off levels for diagnosis of hypertension. CT was significantly thinner in the patient group than in the control group (385.4 μm vs 331.71 μm, respectively, P < 0.03). No significant difference was found between the groups in respect of GCL, IPL, and RNFL values. The higher IOP and OPA values of the children with T1DM and CeD were considered to be the result of the microvascular pathologies in T1DM and increased inflammation associated with CeD. High IOP and OPA values can lead to damage in the eye as intraocular blood flow and choroidal perfusion are affected. In order to prevent these eye problems, measurement of IOP and OPA should be done in children with diagnosis of T1DM and CeD and also follow up studies needed.

Ocular pulse amplitude and hemodynamic in controlled asymmetric glaucoma: a cross-sectional study

Purpose: The aim of this study was to explore the relationship between glaucoma severity, ocular pulse amplitude (OPA), and hemodynamic variables.&#x0D; Methods: Thirty-one Asymmetric primary open-angle glaucoma (POAG) cases (one eye with better MD, fellow eye with worst MD) who applied to the glaucoma outpatient clinic of Gulhane Military Medical Faculty Hospital between January 1, 2006, and June 30, 2007, were included in this cross-sectional study. Patients using beta-blockers or alpha-adrenergic agonists were excluded. The patients went on using glaucoma medications. Asymmetricity was assessed if a visual field means deviation (MD) difference ≥6 decibels existed between the eyes. Mean MD and pattern standard deviation, diurnal OPA, and intraocular pressure( IOP) (7 am, 9 am, 11 am, 1 pm, 3 pm, 5 pm, 7 pm, 9 pm,11 pm, 1 am, 4 am), central corneal thickness, peak systolic velocity (PSV), end-diastolic velocity (EDV), PSV/EDV, pulsatility index (PI), resistivity index (RI) for internal carotid artery and ophthalmic artery were measured with color Doppler ultrasonography.&#x0D; Results: The differences in mean diurnal IOP and mean diurnal OPA between the eyes were statistically insignificant. Each diurnal IOP and OPA values and coefficient of variability of diurnal IOP and OPA were statistically insignificant between the groups. There was no significant difference in PSV, EDV, PSV/EDV, PI, and RI between the better-MD and worse-MD eyes. The correlations between mean IOP/mean OPA, and each diurnal IOP/OPA values were insignificant.&#x0D; Conclusion: These results suggest that ocular hemodynamics are affected after a critical point in the evolution of glaucoma. The severity of glaucoma is not directly related to pulsatile ocular blood flow.

Changes in ocular pulse amplitude and posterior ocular structure parameters in type 1 diabetic children without diabetic retinopathy.

Background:It is important to determine changes in posterior ocular structures in the early period before retinopathy develops in pediatric patients with type 1 diabetes mellitus (DM).Objective:To evaluate inner plexiform layer (IPL), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL) thicknesses, as well as the relationship between choroidal thickness (CT) and ocular pulse amplitude (OPA) in type 1 diabetic children without diabetic retinopathy (DR).Design:A prospective observational study.Methods:Group 1 (n = 44) consisted of pediatric patients with type 1 DM without DR, and Group 2 (n = 65) of pediatric control subjects. Both intraocular pressure (IOP) and OPA were measured using a dynamic contour tonometer. CT, IPL, GCL, and RNFL were all measured using spectral domain optical coherence tomography (OCT).Results:The mean IOP and OPA values were 16.67 ± 2.34 and 1.85 ± 0.34, respectively, in group 1, and 15.14 ± 2.17 and 1.65 ± 0.25 in Group 2 (p = 0.001 for both). The mean subfoveal CT value was 294.30 ± 67.61 μm in group 1 and 394.42 ± 69.65 μm in Group 2 (p < 0.001). The mean GCL and RNFL values were 1.09 ± 0.11 and 96.46 ± 11.69, respectively, in group 1, and 1.14 ± 0.09 and 101.73 ± 9.33 in Group 2 (p = 0.005 and p = 0.008, respectively).Conclusions:IOP and OPA values were higher, and CT, GCL, and RNFL values were lower in children with type 1 DM during the early stages than in the healthy control group. These findings suggest that CT may be a marker of retinal involvement in children with type 1 DM without DR.

Changes in intra-ocular pressure, ocular pulse amplitude and choroidal thickness after trabeculectomy

ABSTRACT Clinical relevance Glaucoma is one of the most common causes of blindness. Although high intra-ocular pressure (IOP) is the most important risk factor, ocular blood flow also has an effect on prognosis. Background The aim of this study was to investigate the IOP, ocular pulse amplitude (OPA) and choroidal thickness (CT) changes after trabeculectomy and to determine whether trabeculectomy has an effect on ocular blood flow. Methods This retrospective, comparative case series was conducted with 33 eyes of 33 patients who underwent trabeculectomy due to uncontrolled glaucoma. The fellow eyes of 20 patients who were followed up with medical therapy were included as a control group. IOP and OPA were evaluated using a dynamic contour tonometer. Subfoveal choroidal thickness (SFCT) was obtained with enhanced depth imaging (EDI) mode of Spectralis-OCT. Results The mean IOP was 21.6 ± 6.3 mmHg at baseline and 13.8 ± 0.9 mmHg after trabeculectomy (p ˂ 0.001), and the mean OPA was 4.1 ± 1.5 at baseline and 2.6 ± 1.6 mmHg after trabeculectomy (p ˂ 0.001). The mean SFCT was 292.2 ± 63.2 µm at baseline and 303.8 ± 70.4 µm after trabeculectomy (p = 0.024). The change in OPA was strongly positively correlated with the change in IOP (r = 0.597, p ˂ 0.001) and SFCT change was positively correlated with OPA change (r = 0.34, p = 0.05). There was no difference between the two groups in terms of IOP, OPA and SFCT values measured after trabeculectomy (respectively, p = 0.264, p = 0.627 and p = 0.949). Conclusion The large IOP decrease following trabeculectomy causes a decrease in OPA and choroidal thickening. On the other hand, trabeculectomy has no effect on OPA change.

Effect of adding clonidine to lidocaine on ocular hemodynamics during sub-Tenon’s anesthesia: randomized double-blind study

Introduction and objectivesDifferent regional anesthesia techniques for ophthalmology can have hemodynamic effects on the eye. We assessed the effects of adding clonidine to lidocaine on Intraocular Pressure (IOP), Ocular Pulse Amplitude (OPA), and Ocular Perfusion Pressure (OPP) after the sub-Tenon’s technique for cataract surgery. MethodsThe study included 40 patients randomly allocated into two groups: sub-Tenon’s blockade with Lidocaine plus Saline Solution (LS) or Lidocaine plus Clonidine (LC). IOP, OPA and OPP were measured before anesthesia, and 1, 5 and 10 minutes after the injection of anesthetic solution. ResultsThere was no difference between the groups in IOP, OPA, and OPP baseline values. After the injection of the anesthetic solution, the IOP increased in both groups at minute one, with a mean difference of +4.67 mmHg (p = 0.001) and +2.15 mmHg (p = 0.013) at 5 minutes. The increase was lower in the LC group when compared to LS (p = 0.027). OPA decreased in both groups, with a baseline difference, after 1 minute, of -0.85 mmHg (p = -0.85 mmHg (p = 0.001), and at 5 and 10 minutes with differences of -1.17 (p = 0.001) and -0.89 mmHg (p = 0.001), respectively. The highest decrease was observed in group LC in relation to group LS (p = 0.03). There was no difference in OPP in relation to baseline measurements. ConclusionsAdding clonidine to lidocaine for sub-Tenon’s anesthesia reduced IOP and OPA without significant changes in OPP.

Changes in ocular pulse amplitude and choroidal thickness in childhood obesity patients with and without insulin resistance.

To compare choroidal thickness (CT) and ocular pulse amplitude (OPA) in childhood obesity with insulin resistance (IR) and without IR. Seventy-three childhood obesity and 62 healthy children, who were both age-matched and gender-matched, comprised the study population in this prospective study. Obesity was determined as having a body mass index (BMI) - standard deviation (SD) score that was > 2 SD.Intraocular pressure (IOP) and OPA were measured using a dynamic contour tonometer. The CT measurements were performed using enhanced depth imaging optical coherence tomography at three locations, comprising at the fovea, at a position 500 µm nasal, and also at a position 500 µm temporal to the fovea. Mean BMI value was 28.72 ± 4.85 in the patients with childhood obesity and 21.47 ± 1.14 in the control group. The mean IOP and OPA values were determined 15.90 ± 2.30 and 14.10 ± 2.16 mm Hg, 1.50 ± 0.28 and 1.74 ± 0.32 mm Hg in the patients with childhood obesity and the control group, respectively (p < 0.001, p < 0.001). The mean subfoveal CT value was 350.50 ± 81.51 μm in the eyes with childhood obesity and 390.02 ± 71.50 μm in those of the control group (p = 0.003). When the patient groups with and without IR were compared, no significant difference was found between CT, OPA and IOP values (p > 0.005). Our results showed that both OPA and CT values were significantly decreased in childhood obesity patients. We suggest further studies to verify longitudinal changes in OPA and CT, as also the evaluation of these parameters in other populations.

Multimodal ocular evaluation in hemodialysis patients.

To evaluate choroidal thickness, intraocular pressure (IOP), axial length, central corneal thickness (CCT), lens thickness, anterior chamber depth, and ocular pulse amplitude (OPA) in hemodialysis patients. The patients with end-stage renal disease and undergoing hemodialysis were included in the study. Immediately before and 1 hour after hemodialysis, all patients underwent measurement of choroidal thickness with spectral domain optical coherence tomography (SD-OC, Cirrus HD-OCT; Carl Zeiss Meditec Inc., Dublin, CA), IOP and OPA with Pascal dynamic contour tonometry (Ziemer Ophthalmic Systems AG, Port, Switzerland), and anterior chamber depth, lens thickness, and axial length with optical biometry (LenStar LS900; Haag-Streit AG, Koeniz, Switzerland). Data from the patients' right eyes were included in the statistical analysis. The patient group included 8 (36.4%) males and 14 (63.6%) females with a mean age of 56, 14 ± 9, 96 (40-70) years. The mean subfoveal choroidal thickness before and after hemodialysis was 255.21 ± 6.15 (245-263) µm and 234.95 ± 7.89 (220-247) µm, respectively (p < 0.001). Mean choroidal thickness at 1500µm and 3000µm nasal and temporal of the fovea also decreased significantly after hemodialysis (p < 0.001). Mean OPA values before and after hemodialysis were 2.14 ± 1.07 (0.6-4) mmHg and 1.6 ± 0.86 (0.5-3.2) mmHg, respectively (p < 0.001). There was a statistically significant correlation between OPA and choroidal thickness measurements (p < 0.001, R = 0.923). IOP increased from 15.11 ± 2.58 (11-20) to 15.99 ± 2.21 (13-20) mmHg, but the change did not reach statistical significance (p = 0.05). There was no statistically significant change in mean axial length, anterior chamber depth, lens thickness, or CCT after hemodialysis (p > 0.05 for all). Although choroidal thickness and OPA may be decreased immediately after hemodialysis, there may be no significant changes in IOP or avascular ocular structures such as the lens and cornea.

First-in-human continuous 24-hour measurement of intraocular pressure and ocular pulsation using a novel contact lens sensor

Background/AimsThis study assessed the feasibility of a novel contact lens device for intraocular pressure (IOP) and ocular pulse amplitude (OPA) continuous measurements over 24 hours.MethodsThis prospective, open-label, single-centre, non-randomised study...

Evaluation of ocular pulse amplitude in patients with carotid artery stenosis using the Pascal dynamic contour tonometer

BackgroundTo evaluate ocular pulse amplitude (OPA) in patients with carotid artery stenosis (CAS) using the Pascal dynamic contour tonometer (DCT).MethodsConsecutive patients who underwent ultrasound Doppler examination of the carotid artery for the suspicion of CAS were prospectively enrolled in the study. Each patient underwent a complete ocular examination. OPA was measured using Pascal DCT. The participants were divided into four groups according to the degree of CAS: Group 1 (no occlusion, control group), Group 2 (mild occlusion: < 50 per cent), Group 3 (moderate occlusion: 50–69 per cent), and Group 4 (severe occlusion: ≥ 70 per cent).ResultsA total of 161 eyes of 81 patients were included in the study. Of the 81 patients, 50 (61.7 per cent) were male, and 31 (38.3 per cent) were female. The mean age was 66.6 ± 12.3-years (range, 20–91-years). Mean OPA values were found to be 2.68 ± 0.97-mmHg in Group 1 (n = 64 eyes), 2.62 ± 0.83-mmHg in Group 2 (n = 49 eyes), 2.30 ± 0.97-mmHg in Group 3 (n = 27 eyes) and 1.66 ± 0.59-mmHg in Group 4 (n = 21 eyes). There was no statistically significant difference in mean OPA levels between Group 1 and Group 2 (p = 0.73). However, statistically significant differences were found between the other groups when they were compared with each other (Groups 1 and 3, p = 0.02; Groups 1 and 4, p < 0.001; Groups 2 and 3, p = 0.02; Groups 2 and 4, p < 0.001; Groups 3 and 4, p = 0.002).ConclusionOPA decreases in patients with moderate to severe CAS. OPA measurement with Pascal DCT can be used as a screening test for CAS.

Analysis of ocular pulse amplitude values in different pregnancy stages as measured by dynamic contour tonometry

Analysis of ocular pulse amplitude values in different pregnancy stages as measured by dynamic contour tonometry

Evaluation of choroidal perfusion changes in obese patients: ocular effects of insulin resistance

We aimed to evaluate choroidal per-fusion changes in obese patients using optical coherence tomography and dynamic contour tonometry, to determine whether these changes are associated with body mass index, and to assess the ocular effects of insulin resistance. We retrospectively evaluated the data of 32 obese patients with body mass index >30 kg/m2 and 45 healthy control individuals. Intraocular pressure and ocular pulse amplitude values of the patients were measured using dynamic contour tonometry, and the mean choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Insulin resistance was assessed using the homeostasis model assessment-estimated insulin resistance index. The mean choroidal thickness (294.30 ± 60.87 μm) and ocular pulse amplitude (2.10 ± 0.74) were lower, whereas the mean intraocular pressure (16.61 ± 2.35 mmHg) was higher in obese patients than in controls. There was a significant negative correlation between body mass index and ocular pulse amplitude (r=-0.274; p=0.029) and an insignificant negative correlation between mean choroidal thickness, intraocular pressure, and body mass index. There was an insignificant negative correlation between homeostasis model assessment-estimated insulin resistance index, mean choroidal thickness, and intraocular pressure and significant ne-gative correlation between homeostasis model assessment-estimated insulin resistance index and ocular pulse amplitude (r=-0.317; p=0.022). We found reduced mean choroidal thickness and ocular pulse amplitude and increased mean intraocular pressure in obese patients. These changes indicated a decrease in choroidal perfusion and ocular blood flow. It may be possible to detect ocular blood flow changes in obese patients through noninvasive assessment using the choroid. The negative correlation between insulin resistance and ocular pulse amplitude may be associated with intracellular fat accumulation in obese patients.

Ocular pulse amplitude in different types of glaucoma using dynamic contour tonometry: Diagnosis and follow-up of glaucoma.

The aim of the present study was to compare the ocular pulse amplitude (OPA) in patients with different types of glaucoma using dynamic contour tonometry (DCT), to evaluate ocular and systemic factors associated with the OPA and to verify whether OPA measured by DCT is an independent predictor for glaucoma diagnosis. A total of 217 eyes of 217 participants in the following five groups were included in this cross-sectional study: Chronic angle closure glaucoma (CACG), primary open angle glaucoma, normal tension glaucoma (NTG), suspected open angle glaucoma (SOAG) and normal control (NC). The following tests were simultaneously performed during a single visit: Intra-ocular pressure (IOP), OPA, cup-to-disk (C/D) ratio, mean damage (MD) and loss variance (LV). OPAs were compared in each group. The association between OPA and IOP, age, C/D ratio, MD and LV was detected. OPA analysis prior to and after trabeculectomy was also performed to assess its prognostic value. Among the 217 individuals, the OPA was consistent with the IOP, both measured by DCT, along with the MD and LV. Patients with CACG and SOAG had higher OPA values than those with NTG and normal controls. Compared with patients aged >30 years, the OPA was significantly lower in younger patients, while they may not have been affected by different C/D ratios. After trabeculectomy, the OPA had significantly decreased compared with the values prior to surgery. In conclusion, the present study showed that the OPA is correlated with the IOP determined by DCT. CACG and SOAG patients had higher OPA values than patients with other types of glaucoma. OPA measured by DCT may be a predictor for glaucoma diagnosis and prognosis.

Evaluation of the effects on choroidal thickness of bimatoprost 0.03% versus a brinzolamide 1.0%/timolol maleate 0.5% fixed combination

Objective: To investigate the effects of two different medical treatment options on choroidal thickness (CT) in cases of open-angle glaucoma (OAG).Methods: Sixty-seven eyes newly diagnosed with OAG and 52 healthy eyes constituting the control group were included in the study. Glaucomatous eyes were randomly divided into two subgroups; Group I was started on bimatoprost 0.03% and Group II on a brinzolamide 1.0%/timolol maleate 0.5% fixed combination (BTFC). Intraocular pressure (IOP), ocular pulse amplitude (OPA) and subfoveal CT measurements were performed in all eyes in the study before treatment and on weeks 2, 4 and 8 after treatment.Results: Mean initial IOP values in groups I and II and the control group were 25.5 ± 4.7, 25.1 ± 5.2 and 16.1 ± 2.9 mmHg, mean OPA values were 3.7 ± 1, 3.6 ± 1.4 and 2.4 ± 0.6 mmHg and mean CT values were 269.4 ± 83, 264.5 ± 84.4 and 320.1 ± 56.6 μm, respectively. Eight weeks after treatment, mean IOP values in Groups I and II and the control group were 18.3 ± 2.6, 18.1 ± 3.4 and 15.7 ± 2.9 mmHg, mean OPA values were 2.9 ± 1.2, 2.8 ± 1.5 and 2.3 ± 0.8 mmHg and mean CT values were 290.2 ± 87.3, 271.8 ± 82.5 and 319.3 ± 56.8 μm, respectively. No significant difference was determined in terms of the decrease in IOP and OPA obtained after treatment in Group I and Group II. However, a significant difference was observed between the two groups in terms of choroidal thickening after treatment.Conclusion: The use of topical ocular hypotensive medication in eyes with OAG results in an increase in CT. This increase is relatively greater with bimatoprost 0.03% therapy compared to BTFC.

Evaluation of ocular pulse amplitude and choroidal thickness in diabetic macular edema.

The aim of this study is to evaluate the ocular pulse amplitude (OPA) and choroidal thickness (CT) measurements in patients with diabetic macular edema (DME) and healthy subjects. A total of 34 patients (12 male and 22 female) who had type 2 diabetes mellitus with DME and 34 sex-matched healthy subjects (13 male and 21 female) were included in this prospective study. The intraocular pressure (IOP) and OPA were measured with Dynamic contour tonometer (Pascal DCT, Switzerland). The subfoveal CT was measured using the Cirrus HD-OCT (Carl Zeiss Meditec). The CT at 1500 μm and 3000 μm nasal and temporal to the central fovea was also measured. The mean IOP values were 18.4±3.5 and 17.1±2.1 mm Hg in DME patients and healthy controls, respectively (P= 0.091). The mean OPA values in patients with DME (2.58±0.96) and controls (3.52±1.03) were statistically different (P<0.001). The mean subfoveal CT value was 273.5±30.2 μm in the eyes with DME and 321.4±36.5 μm in the control group (P< 0.001). In both groups, linear regression analysis showed no significant association between OPA and CT measurements. The IOP showed a significantly positive correlation with OPA in both DME (P=0.002, r=0.526) and controls (P=0.004, r=0.483). The current study suggests that both pulsatile choroidal blood flow and CT are decreased in patients with DME.

Acute effects of caffeine on choroidal thickness and ocular pulse amplitude

Objective: To explore ocular changes in healthy people after caffeine consumption.Methods: This prospective observational study was carried out with students of the Turgut Özal University Medical Faculty from May 15 to 15 December 2014. Enrolled in the study were 17 healthy subjects (n = 17 eyes), with a median age of 24 (IQR 1), ranging between 21 and 26 years. The control group (6 females, 11 males) aged between 23 and 28 (median 25 years [IQR 4.75]). For study, one eye from each participant was randomly selected. To obviate the effect of diurnal variations, tests were performed at the same time of the day (10:00 a.m.–12:00 p.m.). Each subject was given an ophthalmologic examination before the study to exclude those with undiagnosed ocular disease. Version 6.0 Cirrus high-definition optical coherence tomography (HD-OCT) (Carl Zeiss Meditec, Dublin, CA) was used to measure CT at the fovea, and 1500 μm nasal and 1500 μm temporal to the fovea. After baseline OCT measurements, participants were asked to have 200 mg oral caffeine intake or a placebo capsule (200 mg lactose powder). Two further OCT measurements were applied at the first and fourth hours of caffeine intake. All participants also had intraocular pressure (IOP) and ocular pulse amplitude (OPA) measurements recorded before, first and fourth hours of caffeine intake. IOP and OPA were measured using the dynamic contour tonometry (DCT) (Swiss Micro Technology AG, Port, Switzerland).Results: The groups showed no significant difference by means of age, gender, spherical refraction and axial length (p > 0.05). Baseline choroidal thickness measurements of the study and control group showed no significant difference. Oral caffeine intake caused a significant reduction in choroidal thickness compared with baseline, at all three measurement points, (p < 0.05). There were no significant changes in IOP and OPA measurements compared with the baseline values (p > 0.05). The choroidal thickness still continued to decrease for at least 4 h following caffeine intake; whereas, the difference between 1 and 4 h was not statistically significant (p > 0.05). However, choroidal thicknesses, IOP and OPA values of the control group revealed no significant difference at all points when comparing measurements at baseline with 1 and 4 h after placebo intake (p > 0.05).Conclusions: We found no significant change in IOP and OPA following oral 200 mg caffeine intake, while CT significantly decreased, for at least 4 h.

Choroid thickness and ocular pulse amplitude in migraine during attack.

To compare the choroidal thickness and ocular pulse amplitude (OPA) measurements obtained during the attack period in migraine patients and age and gender matched control group participants using high definition optical coherence tomography (OCT). Thirty eyes at the side of the headache of 30 subjects with a diagnosis of migraine with or without aura and unilateral migraine and 29 age and gender matched healthy participants were enrolled in this observational, cross-sectional study. OCT scans were performed to all participants. Choroidal thicknesses were measured at the fovea, 1500 μm nasal and 1500 μm temporal to the fovea. Intraocular pressure (IOP) and OPA were also measured. The choroidal thickness measurements obtained during the attack period in migraine patients were (mean±SD) 279.82±35.87, 250.05±29.49, and 239.58±27.92 and in control group were 308.20±44.97, 276.95±41.39, and 281.60±41.38 at foveal, nasal, and temporal measurement points, respectively. Choroidal thickness significantly decreased according to the control group (P<0.05) at all measured points in migraine patients during attack. IOP (mean±SD) values were 16.71±3.26 and17.40±3.19 and OPA (mean±SD) values were 2.26±0.81 and 2.64±1.03 in migraine and control groups, respectively, and did not seem to be changed (P>0.05). Choroidal thickness was found to be significantly decreased in unilateral migraine patients during the attack period when compared with the control group, whereas OPA did not change. The possible implications of these findings on the association between migraine and glaucoma are discussed.

Ocular pulse amplitude measurement using pascal dynamic contour tonometer in glaucoma patients.

This study aims to measure and compare the ocular pulse amplitude using Pascal dynamic contour tonometry in normal persons and in glaucoma patients. 20 patients (40 eyes) with primary open angle glaucoma (Group A), 8 patients (16 eyes) with normal tension glaucoma (Group B), and 12 patients (24 eyes) with ocular hypertension (Group C) were included in the study. Control group (Group D) comprised 25 normal volunteers (50 eyes). Intraocular pressure was measured using both Goldmann applanation tonometry in the slit-lamp and Pascal dynamic contour tonometry. Ocular pulse amplitude was evaluated with Pascal dynamic contour tonometry. Statistical evaluation of the differences in ocular pulse amplitude and intraocular pressure among the different groups was performed using Student's t-test. Mean ocular pulse amplitude values expressed in mmHg were 3.66 ± 1.00, 2.46 ± 0.60, 4.04 ± 1.47, and 2.52 ± 0.52, for Groups A, B, C, and D, respectively. The ocular pulse amplitude was significantly higher in Group A (primary open angle glaucoma) and Group C (ocular hypertension) when compared with Group D (control group) and Group B (normal tension glaucoma). No statistically significant difference was detected between Group D (control group) and Group B (normal tension glaucoma). Although we can measure the intraocular pressure with Goldmann applanation tonometry, no information can be derived regarding the ocular pulse amplitude. The use of Pascal dynamic contour tonometry in intraocular pressure estimation provides useful clinical information also about the magnitude of the ocular pulse amplitude in different types of glaucoma. Pascal dynamic contour tonometry discloses an elevation of ocular pulse amplitude in primary open angle glaucoma and ocular hypertension patients. On the contrary, the ocular pulse amplitude is within normal limits in normal tension glaucoma patients.

Choroidal changes after cardiopulmonary bypass

Choroid, which is the vascular tissue responsible for blood supply to the outer parts of the retina, might be affected by hemodynamic events. We aimed to reveal choroidal thickness and ocular pulse amplitude changes after cardiopulmonary bypass in which gross hemodynamic alterations occur. Forty-two eyes of 42 patients who underwent heart surgery with cardiopulmonary bypass were examined in this prospective, cross-sectional case series. The spectral domain optical coherence tomography (Spectralis, Heidelberg, Germany) was used to analyze sub-foveal choroidal thickness. The ocular pulse amplitude, the surrogate of gross choroidal blood flow, was measured with the Pascal dynamic contour tonometer (Pascal DCT, Swiss Microtechnology AG, Port, Switzerland).. The intraocular pressure was also measured with this tonometer. The examinations were performed pre-operatively and post-operatively at the first week and first month. The mean age of the patients was 58.8 ± 12.4 years. The mean sub-foveal choroidal thickness and ocular pulse amplitude values did not change statistically significantly after the operations at the follow-up visits (p>0.05). Also, there were no important correlations between cardiopulmonary bypass time and mean sub-foveal choroidal thickness and ocular pulse amplitude changes at the post-operative first week (p>0.05). The intraocular pressure values were decreased markedly at the control visits (p<0.05). Sub-foveal choroidal thickness and ocular pulse amplitude are unchanged, while intraocular pressure decreases one week and one month after cardiopulmonary bypass.

Effects of phacoemulsification surgery on ocular hemodynamics.

To evaluate the possible effects of phacoemulsification cataract surgery on ocular hemodynamics. In this prospective study, intraocular pressure (IOP), pulsatile ocular blood flow (POBF), and ocular pulse amplitude (OPA) were measured pre-operatively (baseline) and at 1 week and 3 weeks postoperation in 52 eyes of 26 patients (mean age 63.15±10.25 years) scheduled for unilateral phacoemulsification cataract surgery with intraocular lens implantation. In all of the eyes, a blood flow analyzer (Paradigm DICON; Paradigm Medical Industries Inc.; USA) was used to obtain measurements of IOP, POBF, and OPA. The data obtained from operated eyes were compared statistically to untreated fellow phakic eyes of the patients. For operated eyes, the mean baseline IOP, POBF, and OPA values were 15.9±4.64mmHg, 17.41±4.84µL/s, and 2.91±1.12mmHg, respectively. The IOP, POBF, and OPA values were 17.19±4.34mmHg, 17.56±6.46µL/s, and 3.12±1.1mmHg, respectively, in the nonoperated control eyes. Statistically significant differences from baseline measurements were not observed 1 week and 3 weeks postoperation for the operated or nonoperated eyes. There were also no statistically significant differences in any measurements between the operated and nonoperated eyes in all the examination periods (P>0.05 for all). Uncomplicated phacoemulsification surgery does not affect ocular hemodynamics in normotensive eyes with cataracts.

Correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes

BackgroundThe purpose of this study was to investigate the correlation between ocular perfusion pressure and ocular pulse amplitude in glaucoma, ocular hypertension, and normal eyes.MethodsNinety eyes from 90 patients were included. Thirty patients had been recently diagnosed with glaucoma and had no previous history of treatment for ocular hypotension, 30 had elevated intraocular pressure (IOP) without evidence of glaucoma, and 30 had normal IOP (<21 mmHg) with no detectable glaucomatous damage. Goldmann applanation tonometry (GAT), dynamic contour tonometry (DCT), blood pressure measurement, pachymetry, Humphrey visual field, and routine ophthalmic examination was performed in each patient. Ocular perfusion pressure was calculated as the difference between mean arterial pressure and IOP. The ocular pulse amplitude was given by DCT. The Pearson correlation coefficient was used to compare the glaucomatous and ocular hypertensive groups, and comparisons with the normal IOP group were done using the Spearman’s rank correlation coefficient.ResultsMean IOP by DCT was 22.7 ± 4.3 mmHg in the glaucoma group, 22.3 ± 2.8 mmHg in the ocular hypertension group, and 14.3 ± 1.6 mmHg in the control group. Mean IOP by GAT was 19.0 ± 5.1 mmHg for glaucoma, 22.4 ± 2.1 mmHg for ocular hypertension, and 12.9 ± 2.2 mmHg for controls. Mean ocular pulse amplitude was 3.4 ± 1.2 mmHg in the glaucoma group, 3.5 ± 1.2 mmHg in the ocular hypertension group, and 2.6 ± 0.9 mmHg in the control group. Mean ocular perfusion pressure was 46.3 ± 7.9 mmHg in the glaucoma group, 46.3 ± 7.9 mmHg in the ocular hypertension group, and 50.2 ± 7.0 mmHg in controls. No significant correlation between ocular perfusion pressure and ocular pulse amplitude was found in any of the groups (P = 0.865 and r = −0.032, P = 0.403 and r = −0.156, P = 0.082 and ρ = −0.307 for glaucoma, ocular hypertension, and normal eyes, respectively).ConclusionThere is no significant correlation between ocular perfusion pressure and ocular pulse amplitude values in glaucoma, ocular hypertension, or normal eyes. IOP values measured by GAT correlate with those measured by DCT.