The effect of flammer-syndrome on retinal venous pressure

Validation of Diagnostic Codes to Identify Glaucoma in Taiwan's Claims Data: A Multi-Institutional Study

Background

Healthcare databases play a crucial role in improving our understanding of glaucoma epidemiology, which is the leading cause of irreversible blindness globally. However, the accuracy of diagnostic codes used in these databases to detect glaucoma is still uncertain.

Aim

To assess the accuracy of ICD-9-CM and ICD-10-CM codes in identifying patients with glaucoma, including two distinct subtypes, primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods

We analyzed electronic medical records data from a 2% random sample of patients who newly underwent visual field examination in Taiwan's largest multi-institutional healthcare system from 2011 to 2020. The diagnosis of glaucoma was confirmed by two ophthalmologists, based on the glaucoma diagnostic criteria. The positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity for ICD-9-CM codes 365.1X and 365.2X, and ICD-10-CM codes H4010X, H4011X, H4012X, H4020X, H4021X, H4022X, H4023X and H4024X for glaucoma were calculated.

Results

We randomly selected 821 patients (mean age: 56.9 years old; female: 50.5%) from the original cohort of 41,050 newly receiving visual field examination in the study. Among 464 cases with an ICD-9-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 86.5, 96.5, 91.9, and 90.9%, respectively. Among 357 cases with an ICD-10-CM glaucoma code, the sensitivity, specificity, PPV and NPV for glaucoma were 87.0, 92.8, 92.2 and 87.9%, respectively. The accuracy of diagnostic codes to identify POAG and PACG remained consistent.

Conclusion

The diagnostic codes were highly reliable for identifying cases of glaucoma in Taiwan's routine healthcare practice. These results provide confidence when using ICD-9-CM and ICD-10-CM codes to define glaucoma cases in healthcare database research in Taiwan.

[Glaucoma Patient with Suspected Flammer Syndrome: Diagnostic Procedures and Therapeutic Implications]

If glaucoma damage develops despite normal intraocular pressure or if the damage progresses despite well-controlled intraocular pressure, we usually find other risk factors. One important group are the vascular factors. We should focus not only on the classical risk factors of atherosclerosis, such as arterial hypertension or dyslipidaemia, but also on dysregulation of blood flow, especially on primary vascular dysregulation (PVD). Low blood pressure, either current or in adolescence, low body mass index or frequently cold hands and feet may provide important hints. Very often PVD is coupled with a number of other symptoms and signs, and we then speak of a Flammer Syndrome (FS). If there is any indication of FS, we take a targeted patient history, undertake 24 h blood pressure monitoring, measure retinal venous pressure, and perform a dynamic retinal vessel analysis or nail fold capillary microscopy. This is especially recommended if the patient is relatively young or the damage is progressing rapidly. If the suspicion is confirmed, we then try to reduce the drops in blood pressure, lower the retinal venous pressure, improve the regulation of blood flow and reduce the oxidative stress in the mitochondria.

Peripapillary Oxygenation and Retinal Vascular Responsiveness to Flicker Light in Primary Open Angle Glaucoma

The aim of our study was to evaluate peripapillary oxygenation and its relationship to retinal vascular responsiveness to flicker light in patients with primary open angle glaucoma (POAG). Retinal vessel oxygen saturation was measured in 46 eyes of 34 Caucasian patients with POAG and in 21 eyes of 17 age-matched controls using the oximetry tool of Retinal Vessel Analyser (RVA: IMEDOS Systems UG, Jena, Germany). The mean oxygen saturation of the major arterioles (A-SO2; %) and venules (V-SO2; %), as well as the corresponding arterio−venular difference (A-V SO2; %), were calculated. We also measured retinal vascular responsiveness (RVR) to flicker light by means of RVA. Glaucoma patients were divided in two subgroups according to their median arteriolar and venular vascular responsiveness to flicker light (AFR and VFR). Glaucomatous damage was assessed by optical coherence tomography (Carl Zeiss Meditec, Dublin, CA, USA) and static automated perimetry (Octopus, program G2/standard strategy: Haag-Streit International, Köniz, Switzerland). In addition, we calculated the mean peripapillary oxygen exposure [ppO2E; %/µm] by dividing the mean A-V SO2 with the mean retinal nerve fibre layer (RNFL) thickness. In glaucoma patients, A-SO2 and V-SO2 values were significantly increased, and their difference decreased when compared to controls (p < 0.017; linear mixed-effects model). Grouped with respect to retinal vascular responsiveness to flicker light, subjects with reduced VFR (≤2.9%) had significantly higher ppO2E (0.49 ± 0.08%/µm, respectively, 0.43 ± 0.06%/µm; p = 0.027). Additionally, higher ppO2E in glaucoma patients correlated negatively with the neuroretinal rim area (p < 0.001) and the RNFL thickness (p = 0.017), and positively with the mean defect of the visual field (p = 0.012). Reduced venular vascular responsiveness in our glaucoma patients was associated with increased peripapillary oxygenation exposure. Thus, ganglion cells and their axons in glaucomatous eyes with reduced retinal vascular responsiveness are prone to be more exposed to higher oxidative stress, probably contributing to the further progression of glaucomatous damage.

Modulation of Human Intraocular Pressure Using a Pneumatic System

Purpose

To technically validate a novel pneumatically based system and method for modulation of intraocular pressure (IOP) and to test its application in the human eye. Special attention was paid to the applicability of the pneumatically driven balloon, which realizes the modulation of the IOP through its contact with the conjunctiva.

Methods

A force sensor as key component of a customized measurement setup was used to check the applied pressure through the balloon. The IOP of 10 healthy subjects (4 female, 6 male, aged 28.8 ± 6.64 years) was modulated and increased linearly to at least 40 mmHg. At this point, the pressure inside the balloon was kept constant for 2 minutes, with IOP measurements taken every 40 seconds using a rebound tonometer.

Results

The technical setup led to an IOP decrease of 0.71 mmHg within 2 minutes at an operating point of 40 mmHg. For all subjects, the IOP could be increased up to 42.8 ± 3.6 mmHg, whereby a mean pressure decrease of 2.4 mmHg/min was determined, which seems to be caused mainly by physiological processes.

Conclusions

With the new pneumatically based setup, a targeted modulation in terms of level and constancy of the IOP can be realized.

Translational Relevance

Additional and, compared with the technique according to Löw, a more precise and more constant methodology for the modulation of the IOP, can significantly simplify the determination of retinal vessel pressures for clinical application. It is suitable for practical questions concerning an enhanced retinal venous pressure.

Treatment of Glaucoma Patients with Flammer Syndrome

Flammer syndrome (FS) describes a phenotype characterized by the presence of primary vascular dysregulation along with a number of symptoms and signs. Although most people with FS are healthy, FS favors the occurrence of certain diseases, such as normal tension glaucoma. This is because disturbed autoregulation makes the eye more sensitive to intraocular pressure (IOP) spikes or blood pressure drops. Treatment of FS is generally appropriate when patients either suffer greatly from their symptoms or if we can assume that it has contributed to a disease. In glaucoma, this may be the case if the glaucoma damage progresses despite well-controlled IOP. Both the still sparse scientific studies and our long clinical experience suggest that FS-targeted therapy not only relieves the symptoms of FS but also slows the progression of glaucoma damage in selected cases. This description is intended not only to help affected patients but to also motivate clinicians and researchers to conduct therapy studies to confirm or refute our observations.

Systemic Vascular Dysregulation May Be Associated With Lower Peripapillary Vessel Density in Non-glaucomatous Healthy Eyes: A Prospective Cross-Sectional Study

Objective: To determine whether systemic vascular dysregulation (SVD) evaluated by nailfold capillaroscope and Flammer Syndrome Questionnaire (FSQ) affects retinal peripapillary microcirculation in non-glaucomatous healthy eyes at steady status. Methods: 120 healthy eyes from 63 non-glaucomatous subjects underwent Optical coherence tomography angiography (OCTA) after a rest of 30 minutes. Average retinal peripapillary capillary (RPC) vessel density (VD) and sectoral VD were automatically calculated, and peripapillary retinal nerve fiber layer thickness (RNFLT) was measured. Vasospastic diathesis was assessed using Flammer Syndrome Questionnaire (FSQ). Cold provocation test (CPT) was performed using nail-fold capillaroscope after OCTA. Positive CPT and a score of FSQ higher than 20% were necessary to determine a subject with SVD. Systemic and ocular parameters were compared between subjects with and without SVD. Results: In this study, heart rate (p = 0.042), ocular perfusion pressure (p = 0.014) and average RPC vessel density (p = 0.046) was significantly different between subjects with and without SVD determined by the combination of CPT and FSQ. Generalized estimation equation (GEE) showed lower VD was significantly associated with longer axial length (β = -0.352, p = 0.001), thinner peripapillary retinal nerve fiber layer thickness (RNFLT) (β = 0.296, p < 0.001), SVD determined by CPT and FSQ (β = 0.617, p = 0.003) and high blood pressure (β = -0.879, p < 0.001). In the superotemporal sector, multivariate model showed only SVD was associated with RPC vessel density (β = -0.811, p < 0.001). Conclusion: In subjects with SVD and non-glaucomatous healthy eyes, lower RPC vessel density in the superotemporal sector was observed. SVD determined by CPT and FSQ was significantly associated with attenuated retinal peripapillary microcirculation. Studies on ocular diseases relevant to vasospasms should consider the effects of SVD on the retinal peripapillary capillaries.

[Vasculat treatment concepts in glaucoma patients]

BACKGROUND

Approximately 40% of all open-angle glaucomas do not show high intraocular pressure (IOP). Vascular risk factors play an important role in the pathogeneses of normal pressure glaucoma but high pressure glaucoma is also often accompanied by significant vascular components.

OBJECTIVE

What are the practice relevant possibilities of vascular glaucoma treatment?

MATERIAL AND METHODS

An evaluation of scientific articles from PubMed dealing with vascular glaucoma was carried out.

RESULTS

The treatment of vascular risk factors in glaucoma patients requires a thorough medical history regarding vascular symptoms (peripheral vasospasm, tinnitus, migraine etc.) and information on the presence of systemic diseases. Furthermore, a 24h blood pressure profile and the determination of the fat metabolism status represent important and simple examinations.

CONCLUSION

Besides optimizing systemic blood pressure, reducing an increased central retinal venous pressure, treatment with statins, calcium channel blockers, Ginkgo biloba extract, increased physical exercise and fluid replacement are options to ameliorate vascular conditions. An interdisciplinary cooperation with general practitioners and internists is an important component of holistic treatment.

The Distribution of Retinal Venous Pressure and Intraocular Pressure Differs Significantly in Patients with Primary Open-Angle Glaucoma

INTRODUCTION

Until now, venous pressure within the eye has widely been equated with intraocular pressure (IOP). Measurements with dynamometers calibrated in instrument units or in force showed that the retinal venous pressure (RVP) may be higher than the IOP in glaucoma patients. In this study, the RVP was measured with a contact lens dynamometer calibrated in mmHg.

METHODS

Study type: cross-sectional.

SUBJECTS

Fifty consecutive patients with primary open-angle glaucoma (POAG) who underwent diurnal curve measurement under medication. Age: 69 ± 8 years. Measurement of RVP: contact lens dynamometry. IOP measurement: dynamic contour tonometry.

RESULTS

Pressures are given in mmHg. In all 50 patients, the IOP was 15.9 (13.6; 17.1) [median (Q1; Q3)], and the RVP was 17.4 (14.8; 27.2). The distribution of the IOP was normal and that of the RVP was right skewed. In the subgroup of 34 patients with spontaneous pulsation of the central retinal vein (SVP), the IOP and therefore, by definition, the RVP was 16.5 (13.7; 17.4). In the subgroup of 16 patients without SVP, the IOP was 14.8 (13.3; 16.4), and the RVP was 31.3 (26.2; 38.8) (p ≤ 0.001). In systemic treatment, the prescribed drugs were (the number of patients is given in parentheses): ACE inhibitors (20), β-blockers (17), angiotensin II-receptor blockers (13), calcium channel blockers (12), diuretics (7). No difference in RVP was observed between patients receiving these drugs and not receiving them, except in the β-blocker group. Here, the 17 patients with systemic β-blockers had a median RVP of 15.6 mmHg and without 20.2 mmHg (p = 0.003). In the 16 patients with a higher RVP than IOP, only one patient received a systemic β-blocker. The median IOP was 15.7 mmHg with systemic β-blockers and 16.1 mmHg without (p = 0.85).

CONCLUSION

In a subgroup of 16 of the 50 patients studied, the RVP was greater than the IOP by a highly statistically and clinically significant degree. According to the widely accepted thinking on the pathophysiology of retinal and optic nerve head circulation, the blood flow in these tissues may be much more compromised in this group of patients than has been assumed. They may be identified by a missing SVP. Topical and systemic medications showed no statistically significant influence on the RVP, except for the systemic β-blockers, in which the RVP was lower by 4.6 mmHg than for the patients who did not receive these drugs (p = 0.003).

Heterogeneity in arterial hypertension and ocular perfusion pressure definitions: Towards a consensus on blood pressure-related parameters for glaucoma studies

PURPOSE

Glaucoma studies have long taken into account the blood pressure (BP) status of patients. This study summarizes and evaluates the impact of the different criteria that have been used for BP-related variables in glaucoma research.

METHODS

Studies included in two meta-analyses that reviewed the role of BP in glaucoma were analyzed. Additional studies published after the search periods of the meta-analyses were also included. Criteria for the definition of arterial hypertension and other BP-related variables, such as mean arterial pressure (MAP) and mean ocular perfusion pressure (MOPP), were retrieved.

RESULTS

Sixty-four studies were evaluated. One-third used 140 mmHg as a systolic BP cut-off to define hypertension, 20% used 160 mmHg and the remaining half used various other criteria. Less than 20% of studies reported MAP and/or MOPP. While eight of the ten studies reporting MAP used a correct formula that only happened for five of the eleven studies reporting MOPP. Using as an example average blood pressure values, incorrectly used formulas could have led to an overestimation of more than 100% of the expected values.

CONCLUSION

Considerable heterogeneity exists in BP-related variables in glaucoma research and different definitions can lead to large disparities. Glaucoma research would benefit from a consensus regarding blood pressure parameters.

Residual vision activation and the brain-eye-vascular triad: Dysregulation, plasticity and restoration in low vision and blindness - a review

Vision loss due to ocular diseases such as glaucoma, optic neuropathy, macular degeneration, or diabetic retinopathy, are generally considered an exclusive affair of the retina and/or optic nerve. However, the brain, through multiple indirect influences, has also a major impact on functional visual impairment. Such indirect influences include intracerebral pressure, eye movements, top-down modulation (attention, cognition), and emotionally triggered stress hormone release affecting blood vessel dysregulation. Therefore, vision loss should be viewed as the result of multiple interactions within a “brain-eye-vascular triad”, and several eye diseases may also be considered as brain diseases in disguise. While the brain is part of the problem, it can also be part of the solution. Neuronal networks of the brain can “amplify” residual vision through neuroplasticity changes of local and global functional connectivity by activating, modulating and strengthening residual visual signals. The activation of residual vision can be achieved by different means such as vision restoration training, non-invasive brain stimulation, or blood flow enhancing medications. Modulating brain functional networks and improving vascular regulation may offer new opportunities to recover or restore low vision by increasing visual field size, visual acuity and overall functional vision. Hence, neuroscience offers new insights to better understand vision loss, and modulating brain and vascular function is a promising source for new opportunities to activate residual vision to achieve restoration and recovery to improve quality of live in patients suffering from low vision.

Transient visual field impairment after cold provocation in glaucoma patients with Flammer syndrome

Background:

It is still debatable whether visual field defects in glaucoma have a reversible component and to what extent a temporary loss can be provoked.

Objective:

To investigate the response of the visual function to a cold provocation in glaucoma patients, particularly to test whether subjects with Flammer syndrome (FS) behaved differently from subjects without FS.

Methods:

Ten (10) primary open-angle glaucoma (POAG) patients with FS, 7 POAG patients without FS, and 11 healthy controls were tested with program G2 on the Octopus 101 perimeter before and after putting one hand in cold water (4°C) for 2 min. The mean sensitivity (MS) of each visual field was included in the statistical analysis.

Results:

In glaucoma patients with FS, the mean MS significantly decreased after cold provocation (delta MS = –0.91 dB, CI = –1.43 to –0.39, p = 0.0014). In contrast, the mean MS in glaucoma patients without FS did not change significantly (delta MS = 0.17 dB, CI = –0.43 to 0.78, p = 0.56). Likewise, the mean MS did not change significantly in the healthy controls (delta MS = 0.23 dB, CI = –0.27 to 0.72, p = 0.36).

Conclusions:

Cold provocation induced a transient visual field deterioration in the glaucoma patients with FS but not in the glaucoma patients without FS or in the healthy controls. We assume this effect to be the result of a transient reduction of ocular blood flow.

In glaucoma patients, low blood pressure is accompanied by vascular dysregulation

Background

There are many risk factors contributing to glaucomatous optic neuropathy. Beside increased intraocular pressure, vascular factors play a prominent role, particularly low blood pressure (BP), and vascular dysregulation. Both of them are essential components of the Flammer syndrome. The aim of this retrospective study was to evaluate whether in glaucoma patients there is a relationship between vascular dysregulation and the BP.

Methods

Medical records of 57 unselected glaucoma patients were retrospectively studied.

Results

Based on the outcome of the capillaroscopy, patients were divided in a group of patients with vascular dysregulation, also called long-stoppers (flow cessation for 13 s or more), and a group of patients with normal vascular regulation, also called short-stoppers (flow cessation for 12 s or less). BP was significantly lower in the group of long-stoppers than in the group of short-stoppers. This applies for both systolic (p = 0.028) and diastolic BP (p = 0.036). The regression analysis revealed also a significant inverse relationship between the duration of blood flow cessation and the systolic (p = 0.025) and diastolic BP (p = 0.016). After adjustment for age, gender, use of antihypertensive therapy, and excluding patients taking calcium channel blockers, the relationship was still significant for systolic (p = 0.025) and diastolic BP (p = 0.003).

Conclusions

In glaucoma patients, vascular dysregulation (as defined by response in the nailfold capillaroscopy to a cold provocation) and low BP are statistically related. This is in line with the observation that Flammer syndrome subjects have both primary vascular dysregulation and low BP and that Flammer syndrome is a risk factor for glaucomatous optic neuropathy, at least in normal tension glaucoma patients. The detection of vascular factors in glaucoma patients may lead to a more efficient treatment, better tailored to the individual patient.

Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventive and personalized medicine

The loss of vision after damage to the retina, optic nerve, or brain has often grave consequences in everyday life such as problems with recognizing faces, reading, or mobility. Because vision loss is considered to be irreversible and often progressive, patients experience continuous mental stress due to worries, anxiety, or fear with secondary consequences such as depression and social isolation. While prolonged mental stress is clearly a consequence of vision loss, it may also aggravate the situation. In fact, continuous stress and elevated cortisol levels negatively impact the eye and brain due to autonomous nervous system (sympathetic) imbalance and vascular dysregulation; hence stress may also be one of the major causes of visual system diseases such as glaucoma and optic neuropathy. Although stress is a known risk factor, its causal role in the development or progression of certain visual system disorders is not widely appreciated. This review of the literature discusses the relationship of stress and ophthalmological diseases. We conclude that stress is both consequence and cause of vision loss. This creates a vicious cycle of a downward spiral, in which initial vision loss creates stress which further accelerates vision loss, creating even more stress and so forth. This new psychosomatic perspective has several implications for clinical practice. Firstly, stress reduction and relaxation techniques (e.g., meditation, autogenic training, stress management training, and psychotherapy to learn to cope) should be recommended not only as complementary to traditional treatments of vision loss but possibly as preventive means to reduce progression of vision loss. Secondly, doctors should try their best to inculcate positivity and optimism in their patients while giving them the information the patients are entitled to, especially regarding the important value of stress reduction. In this way, the vicious cycle could be interrupted. More clinical studies are now needed to confirm the causal role of stress in different low vision diseases to evaluate the efficacy of different anti-stress therapies for preventing progression and improving vision recovery and restoration in randomized trials as a foundation of psychosomatic ophthalmology.

Retinal venous pressure is higher than the airway pressure and the intraocular pressure during the Valsalva manoeuvre

PURPOSE

The aims of this prospective experimental study were to explore the influence of the Valsalva manoeuvre (VM) on retinal venous pressure (RVP) in human volunteers in a university setting and to establish correlations for RVP with the increase in airway pressure (∆AirP) and in intraocular pressure (∆IOP).

METHODS

In total, 31 healthy young volunteers (age: 24 ± 1.7 years) were investigated. The instruments used included a dynamic contour tonometer, a contact lens dynamometer (Imedos) and an electronic pressure transducer for measuring airway pressure. The following measurements were successively performed in left eyes: tonometry, dynamometry, repeated simultaneous dynamometry and airway pressure measurement during the VM and tonometry during the VM. The pressures obtained during the VM were determined at 10, 20 and 30 seconds after onset of the VM by linear interpolation.

RESULTS

The pressures (in mmHg) at baseline and during the VM (median and range with outliers) were as follows: ∆AirP: 10 seconds: 10.0 (7.5); 20 seconds: 12.5 (11.0); and 30 seconds: 11.0 (10.0); and RVP: Start: 17.1 (2.4); 10 seconds: 26.0 (7.5); 20 seconds: 25.0 (6.5); and 30 seconds: 24.0 (6.0). During the VM, the RVP was significantly increased compared with the ∆AirP (p = 0.0017). The IOP during the VM was 13.5 (2.7), and the increase in IOP (∆IOP) was 0.8 (5.6).

CONCLUSION

During the VM, the RVP was increased compared with the ∆AirP. The increase in RVP (∆RVP) was significantly greater than the ∆IOP. During the VM, the calculated retinal perfusion pressure may be more strongly reduced by the ∆RVP than by the ∆IOP. These properties may influence retinal and optic nerve head pathophysiology.

Reactive oxygen species, oxidative stress, glaucoma and hyperbaric oxygen therapy

This review examines the role of oxidative stress in damage to cells of the trabecular meshwork and associated impaired aqueous drainage as well as damage to retinal ganglion cells and associated visual field losses. Consideration is given to the interaction between vascular and mechanical explanations for pathological changes in glaucoma. For example, elevated intraocular pressure (IOP) forces may contribute to ischaemia but there is increasing evidence that altered blood flow in a wider sense is also involved. Both vascular and mechanical theories are involved through fluctuations in intraocular pressure and dysregulation of blood flow. Retinal function is very sensitive to changes in haemoglobin oxygen concentration and the associated variations in the production of reactive oxygen species. Reperfusion injury and production of reactive oxygen species occurs when IOP is elevated or blood pressure is low and beyond the capacity for blood flow autoregulation to maintain appropriate oxygen concentration. Activities such as those associated with postural changes, muscular effort, eye wiping and rubbing which cause IOP fluctuation, may have significant vascular, mechanical, reperfusion and oxidative stress consequences. Hyperbaric oxygen therapy exposes the eye to increased oxygen concentration and the risk of oxidative damage in susceptible individuals. However, oxygen concentration in aqueous humour, and the risk of damage to trabecular meshwork cells may be greater if hyperbaric oxygen is delivered by a hood which exposes the anterior ocular surface to higher than normal oxygen levels. Oronasal mask delivery of hyperbaric oxygen therapy appears to be indicated in these cases.

Retinal venous pressure measurements in patients with Flammer syndrome and metabolic syndrome

Background

The purpose of this research is to analyze retinal venous pressure (RVP) of both eyes of patients who visited a Swiss ophthalmic practice and compare values among the following groups of patients with primary open-angle glaucoma (POAG), Flammer syndrome (FS), and metabolic syndrome (MetS).

Methods

RVP was measured in both eyes of all patients who visited a Swiss ophthalmic practice during March 2016 till November 2016, and the results were analyzed retrospectively. All measurements were performed by one physician by means of ophthalmodynamometry. Ophthalmodynamometry is done by applying an increasing pressure on the eye via a contact lens. The minimum force required to induce a venous pulsation is called ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP].

Results

Spontaneous central retinal venous pulsation was present in the majority of the patients (192 out of 357, 53.8%). Spontaneous RVP rate was significantly negatively correlated with age (r = -0.348, p < 0.001). A significantly increased RVP was noted in FS, MetS, and POAG patients, particularly those POAG patients who also suffered from FS (p < 0.005).

Conclusions

Although most patients had a spontaneous RVP, those with FS, POAG, and MetS had increased RVP. Measuring RVP by means of ophthalmodynamometry provides predictive information about certain ocular diseases and aids in instituting adequate preventive measures.

The potential relationship between Flammer and Sjögren syndromes: the chime of dysfunction

Flammer syndrome (FS) is a term to blanket a cluster of vascular and nonvascular signs and symptoms linked to primary vascular dysregulation (PVD), increased sensitivity to various stimuli (stress, drugs, etc.) and altered sense regulation such as pain, smell and thirst perception. On one hand, disruption of blood barrier and homeostasis of the body are the main targets of vascular irregularity. Inflammation and immune disorders including autoimmunity are considered as a consequence of the abnormal vascular regulation processes. On the other hand, decreased thirst feeling typical for FS-affected individuals may lead to extensive body dehydration resulting in dry eye appearance and breast cancer (BC) risk, amongst others. To this end, recent research demonstrated FS as linked to BC development and progression into the metastatic disease. On the other side, Sjögren syndrome (SS) is an autoimmune disease characterised by a progressive sicca syndrome associated with the dry eye symptoms, specific immunologic complex and/or significant infiltrate at minor salivary gland biopsy. SS is relatively frequent, with a clinical diagnosis predominantly amongst women. Its physiopathology is a complex battery of both environmental and genetic factors. If left untreated, SS may be associated with and/or resulted in severe arthritis and the development of B cell lymphoma. In this mini-review, we summarise the facts and hypotheses connecting FS and SS symptoms together and mechanisms potentially overlapping in both syndromes. Unraveling the common denominators between these two syndromes not only providing more evidence for interaction between altered sense regulation, vascular dysregulation, immune system dysfunction but also focusing on the individual outcomes in terms of severity grade and potential complications exploring novel diagnostic, prognostic and treatment modalities. Multi-professional considerations presented here are an example how to effectively enter the new era of preventive, predictive and personalised medicine benefiting the patients and healthcare system as the whole.

Diseases potentially related to Flammer syndrome

Flammer syndrome (FS) is a prevalent and mostly benign condition. Subjects with FS seem to have a good life expectancy. Nevertheless, FS subjects are at increased risk for certain diseases, mainly when they are challenged by psychological stress or other stimuli such as coldness. FS is related to ocular diseases, such as normal-tension glaucoma, retinitis pigmentosa, central serous chorioretinopathy, optic nerve compartment syndrome, Leber’s hereditary optic neuropathy, arterial or venous occlusions in the retina, and choroid and optic nerve head, despite the absence of classical vascular risk factors. FS is also related to some non-ocular diseases, such as multiple sclerosis, breast cancer, and altitude sickness. The role of FS in other diseases such as tinnitus, sudden hearing loss, Ménière’s disease, anorexia nervosa, and thyroid dysfunction is currently under investigation. The exact relationship of FS to related diseases however still needs to be established. This may hopefully lead to more targeted diagnostics and personalized treatments.

Nutritional recommendations for individuals with Flammer syndrome

The Flammer syndrome (FS) describes the phenotype of people with a predisposition for an altered reaction of the blood vessels to stimuli like coldness or emotional stress. The question whether such people should be treated is often discussed. On the one hand, most of these subjects are healthy; on the other hand, FS seems to predispose to certain eye diseases such as normal tension glaucoma or retinitis pigmentosa or systemic diseases such as multiple sclerosis or tinnitus. A compromise between doing nothing and a drug treatment is the adaption of nutrition. But what do we mean by healthy food consumption for subjects with FS? The adaption of nutrition depends on the health condition. Whereas patients with e.g. a metabolic syndrome should reduce their calorie intake, this can be counterproductive for subjects with FS, as most subjects with FS have already a low body mass index (BMI) and the lower the BMI the stronger the FS symptoms. Accordingly, while fasting is healthy e.g. for subjects with metabolic syndrome, fasting can even dangerously aggravate the vascular dysregulation, as it has been nicely demonstrated by the loss of retinal vascular regulation during fasting. To give another example, while reducing salt intake is recommended for subjects with systemic hypertensions, such a salt restriction can aggravate systemic hypotension and thereby indirectly also the vascular regulation in subjects with FS. This clearly demonstrates that such a preventive adaption of nutrition needs to be personalized.

Breast cancer and Flammer syndrome: any symptoms in common for prediction, prevention and personalised medical approach?

An epidemic scale of the breast cancer (BC) prevalence is actually recognised as the reality of the early twenty-first century. Particularly alarming is that the sporadic BC (about 90% of all patients) creates currently unpredictable subpopulations in terms of disease predisposition, development and progression. Despite broad discussions run since years in BC area, no any plausible approach has been suggested so far to get the overall situation better controlled in the populations. Here, we present highly innovative concepts considering investigation of specific syndromes and symptoms underestimated till now in relationship with BC predisposition and development. Consequently, the purpose of our pilot project was to evaluate the prevalence of Flammer Syndrome (FS) in BC patient cohort. The results achieved here support the main hypothesis of the project clearly demonstrating the tendency of BC patients to the increased prevalence of FS symptoms compared to the disease-free individuals. Our study strongly indicates the relevance of FS symptoms for BC pathology such as feeling inadequately cold, deficient thermoregulation, altered sensitivity to different stimuli, potential dehydration, altered sleep patterns, tendency towards headache, migraine attacks and dizziness. Moreover, the symptoms' appearance is specifically linked to the individual BC subtypes. Potential mechanisms interconnecting FS with BC pathology are discussed.

The discovery of the Flammer syndrome: a historical and personal perspective

This review describes the clinical and basic research that led to the description of Flammer syndrome. It is narrated from a personal perspective. This research was initiated by the observation of an increased long-term fluctuation of visual fields in a subgroup of glaucoma patients. As these patients had strikingly cold hands, peripheral blood flow was tested with a capillary microscopy, and vasospastic syndrome (VS) was diagnosed. Further studies on these patients revealed frequently weakened autoregulation of ocular blood flow and increased flow resistivity in retroocular vessels. Their retinal vessels were more rigid and irregular and responded less to flickering light. Holistic investigation demonstrated low blood pressure, silent myocardial ischaemia, altered beat-to-beat variation, altered gene expression in the lymphocytes, slightly increased plasma endothelin level and increased systemic oxidative stress. This combination of signs and symptoms was better described by the term primary vascular dysregulation (PVD) than by VS. Subsequent studies showed additional symptoms frequently related to PVD, such as low body mass index, cold extremities combined with slightly increased core temperature, prolonged sleep onset time, reduced feelings of thirst, increased sensitivity to smell and also for certain drugs and increased retinal venous pressure. To better characterise this entire syndrome, the term Flammer syndrome (FS) was introduced. Most subjects with FS were healthy. Nevertheless, FS seemed to increase the risk for certain eye diseases, particularly in younger patients. This included normal-tension glaucoma, anterior ischaemic optic neuropathy, retinal vein occlusions, Susac syndrome and central serous chorioretinopathy. Hereditary diseases, such as Leber’s optic neuropathy or retinitis pigmentosa, were also associated with FS, and FS symptoms and sings occurred more frequent in patients with multiple sclerosis or with acute hearing loss. Further research should lead to a more concise definition of FS, a precise diagnosis and tools for recognizing people at risk for associated diseases. This may ultimately lead to more efficient and more personalised treatment.

The trilateral link between anaesthesia, perioperative visual loss and Flammer syndrome

Background

A variety of factors have been linked to perioperative visual loss during or directly after nonocular and ocular surgeries. Prolonged immobilization, biochemical factors and hemodynamic instability have been discussed as factors in the pathogenesis of this devastating complication. Perioperative visual loss in four consecutive patients, all featuring Flammer syndrome, is reported herein. To our knowledge, we present the first case series, which associates perioperative visual loss with Flammer syndrome. We assume that a low perfusion pressure, disturbed autoregulation of the ocular blood flow and altered drug sensitivity in such subjects, play significant role in the pathogenesis of this dreaded complication.

Cases presentation

We analysed the medical records of four consecutive patients with permanent perioperative visual loss and complemented our findings with additional history taking and clinical examinations. A variety of tests was performed, including colour Doppler ultrasonography of the retroocular vessels, static and dynamic retinal vessel analysis. The visual loss was unilateral in three patients and bilateral in one. An extensive review of published perioperative vision loss cases was conducted.

All four patients were male Caucasians, and exhibited prominent signs and symptoms of Flammer syndrome. The visual loss originated from a propensity for unstable ocular blood flow, combined with hyperreactivity toward pharmacological stimuli, leading together to disturbed autoregulation of the blood supply, and subsequently - to ocular hypoxia. An identified intrinsic hypoperfusion diathesis was a crucial pathophysiologic link in all of the patients. Other, yet unknown systemic or local factors may also be involved in this process.

Conclusions

A review of numerous publications of perioperative visual loss and our data, support our hypothesis for a novel pathophysiologic model and incorporate Flammer syndrome as a distinct risk factor for paradoxical visual loss, during nonocular and ocular surgeries, or invasive procedures. To prevent the complications produced by disturbed blood flow autoregulation in such patients, guidelines for screening and tailored preoperative approach are given.

Retinal venous pressure: the role of endothelin

The retinal venous pressure (RVP) can be measured non-invasively. While RVP is equal to or slightly above intraocular pressure (IOP) in healthy people, it is often markedly increased in patients with eye or systemic diseases. Beside a mechanical obstruction, the main cause of such an elevation is a local dysregulation of a retinal vein, particularly a constriction induced by endothelin-1 (ET-1). A local increase of ET-1 can result from a high plasma level, as ET-1 can diffuse from the fenestrated capillaries of the choroid into the optic nerve head (ONH), bypassing the blood retinal barrier. A local increase can also result from increased local production either by a sick neighboring artery or retinal tissue. Generally, the main factors increasing ET-1 are inflammations and hypoxia, either locally or in a remote organ. RVP is known to be increased in patients with glaucoma, retinal vein occlusion (RVO), diabetic retinopathy, high mountain disease, and primary vascular dysregulation (PVD). PVD is the major vascular component of Flammer syndrome (FS). An increase of RVP decreases perfusion pressure, which heightens the risk for hypoxia. An increase of RVP also elevates transmural pressure, which in turn heightens the risk for retinal edema. In patients with RVO, a high level of RVP may not only be a consequence but also a potential cause of the occlusion; therefore, it risks causing a vicious circle. Narrow retinal arteries and particularly dilated retinal veins are known risk indicators for future cardiovascular events. As the major cause for such a retinal venous dilatation is an increased RVP, RVP may likely turn out to be an even stronger predictor.

Retinal venous pressure in chronic smokers

Background

The overall aim of this study was to determine retinal venous pressure (RVP) in healthy chronic smokers and compare values to those of healthy non-smokers.

Methods

Both eyes of 25 healthy chronic smokers and 41 healthy non-smokers were included. Measurements of RVP were performed by means of contact lens ophthalmodynamometry. Ophthalmodynamometry is done by applying increasing force on the eye via a contact lens. If a spontaneous venous pulsation was present, it was noted. If not, the compressive force was increased until the first venous pulsation was detected, and the measurement value was fixed and read. RVP was calculated as the sum of pressure increase induced by the instrument and intraocular pressure.

Results

Smokers had a significantly higher frequency of spontaneous venous pulsations than non-smokers (p < 0.001). Mean values of RVP were slightly lower in smokers than in non-smokers: 15.3 and 15.5 (smokers) versus 15.9 and 16.2 (non-smokers) for the right and left eye, respectively; however, the difference in RVP between the two groups did not reach significance. There was no significant difference in blood pressure between the two groups, but heart rate was significantly higher in smokers (p = 0.043).

Conclusions

RVP values may differ in healthy smokers than in non-smokers. Therefore, smoking habits should be considered when interpreting RVP results.

The effect of nifedipine on retinal venous pressure of glaucoma patients with the Flammer-Syndrome

PURPOSE

The purpose was to measure the retinal venous pressure (RVP) in both eyes of primary open-angle glaucoma (POAG) patients before and 3 weeks after treatment with low-dosed Nifedipine.

METHODS

This retrospective study included 20 POAG patients who were treated with Nifedipine (5 mg daily) and 20 untreated control POAG patients. In both the treated and untreated control group, a distinction was made between those patients who had the Flammer-Syndrome (FS) and those who did not. The RVP was measured in all patients bilaterally at baseline and 3 weeks later by means of contact lens ophthalmodynamometry and the RVP measurements of the treated POAG patients were compared to the RVPs of the untreated POAG controls. Ophthalmodynamometry is done by applying an increasing force on the eye via a contact lens. The minimum force required to induce a venous pulsation is called the ophthalmodynamometric force (ODF). The RVP is defined and calculated as the sum of ODF and intraocular pressure (IOP) [RVP = ODF + IOP].

RESULTS

The RVP decreased significantly after 3 weeks in both eyes of patients treated with low-dosed Nifedipine compared to the untreated group (mean decrease of 12.5 mmHg (SD 12.5), P < 0.001). A larger response to therapy was found in patients with the FS compared to patients lacking the FS (mean decrease of 16.07 vs. 7.28 mmHg, confidence Interval (CI): 5.2 to 9.3 vs. 12.3 to 19.7; P < 0.001). No significant differences were accounted for in the IOP's of the patients after treatment. In the untreated control group, no significant differences were accounted for either in the RVP or the IOP after 3 weeks.

CONCLUSIONS

Treatment with low-dosed Nifedipine decreases RVP in both eyes of glaucoma patients, particularly in those with the Flammer-Syndrome. This effect may be due to the partial inhibition of Endothelin-1 (ET-1) by Nifedipine.