Functional visual loss

The FreiBurger: a new optotype for P300-based acuity estimation

PURPOSE

Accurate objective assessment of visual acuity is crucial, particularly in cases of suspected malingering, or when the patient's inability to cooperate makes standard psychophysical acuity tests unreliable. The P300 component of the event-related potentials offers a potential solution and even allows for the use of standard optotypes like the Landolt C. However, low-vision patients with large eccentric visual field defects often struggle to locate the Landolt C gap quickly enough for a P300 to be reliably produced.

METHODS

Addressing this challenge, we introduce a novel optotype (the "FreiBurger") with a critical detail that extends through the optotype's center. Two experiments, with 16 and 12 participants, respectively, were conducted. In the first, psychophysical acuity estimates were obtained with both the FreiBurger and the Landolt C. In the second, we tested the performance of the FreiBurger, relative to the Landolt C, in eliciting a P300 with undegraded vision, simulated low vision, and in a simulated combination of low vision and visual field constriction.

RESULTS

Comparable psychophysical acuity values (average difference 0.03 logMAR) were obtained for both optotypes. In the P300 recordings, both optotypes produced similar P300 responses under conditions of undegraded vision and low vision. However, with the combination of low vision and constricted visual field, the P300 could only be reliably obtained with the FreiBurger, while the amplitude was drastically reduced with the Landolt C (9.1 µV vs. 2.2 µV; p < 0.0005).

CONCLUSION

The new optotype extends the applicability of P300-based acuity estimation to the frequently encountered combination of low vision and constricted visual field, where Landolt C optotypes fail. Although impairments were simulated in the present study, we assume that the advantages of the new optotype will also manifest in patients with such impairments. We furthermore expect the advantages to apply to time-sensitive psychophysical examinations as well.

Observational cohort study of 100 patients presenting with functional visual loss: clinical characteristics and comparison with other functional neurologic disorders

OBJECTIVE

Recent research has helped to develop a more detailed understanding of many functional neurologic disorders. The aim of this study was to increase our knowledge of functional visual loss and to compare the findings with those of other functional syndromes.

DESIGN

Prospective and retrospective observational cohort study.

METHODS

This study took place at neuro-ophthalmology clinics at 3 major hospitals in London, United Kingdom, over a 12-month period. The study population consisted of 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. All participants had their diagnosis confirmed with a full neuro-ophthalmic examination, neuroimaging, and visual electrophysiology. A full assessment of all participants' medical history was obtained from their general practitioner, and all participants completed a series of questionnaires assessing relevant associations.

RESULTS

Data were obtained on 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. Participants with functional visual loss were typically female (74%) with a mean age at vision loss of 40.0 ± 16 years. Sixty-four percent of participants had bilateral vision loss; the remainder, unilateral loss. Twenty-six percent of the total cohort had organic visual loss with functional overlay. Fifty percent of participants with functional visual loss had a preexisting psychiatric diagnosis, the most common being a depressive disorder. Sixty-two percent of participants had an ocular history, and 87% had a previously diagnosed medical illness, most commonly neurologic (45%). Thirty-five percent of participants self-reported at least 1 additional functional symptom.

CONCLUSIONS

Our population of functional visual loss subjects shares many similarities with the majority of patients with other functional neurologic disorders. They are generally young and female and have a greater than expected rate of psychiatric, medical, and coexisting ocular conditions. We found increased rates of precipitating stressors, clinical depression, and organic eye problems in subjects with functional visual loss.

Functional vision disorder: a review of diagnosis, management and costs

Functional vision disorder (FVD) is a relatively common diagnosis in ophthalmic practice which can be difficult to make because of clinician's apprehension to miss organic pathology. We review the diagnostic approach to patients with FVD, organic mimics of FVD, its diagnostic and management strategies and associated cost burden. Patients with FVD typically present with visual acuity and/or field loss. Diagnostic work-up should include patient observation, detailed history, pupillary examination, dilated ophthalmoscopy, visual field testing and ganglion cell analysis of the macular complex. Most common organic mimickers of FVD are amblyopia, cortical blindness, retrobulbar optic neuritis, cone dystrophy and chiasmal tumours; however, all could be ruled out by structured diagnostic approach. For patients with unilateral visual loss, bottom-up refraction, fogging of the well-seeing eye in the phoropter, convex lens and base-down prism tests could aid in diagnosis. For patients claiming binocular vision loss, checking for eye movement during the mirror test or nystagmus elicited by an optokinetic drum can be helpful. Effective management of FVD involves reassurance, stress reduction and, if agreed on, management of comorbid anxiety and/or depression. The social cost of FVD is predominately economic as patients typically meet several healthcare providers over multiple visits and often undergo several neuroimaging studies before neuro-ophthalmology referral. Further, inappropriate granting of disability benefits confers additional stigma to patients with organic vision loss.

A case of functional visual loss diagnosed through bilateral randomized visual field testing with a trick method

Purpose

To report a case of functional visual loss (FVL) diagnosed through bilateral randomized visual field testing using Imo vifa with a trick method.

Observations

A 27-year-old man complained of visual field abnormality in his left eye after falling from a height of 4 m. The left eye had a best-corrected visual acuity (BCVA) of 20/16 and a critical flicker frequency (CFF) of 44.5 Hz at the first visit. Commotio retinae was observed in the inferior retina of the left eye, and the pupillary light reflex was normal. Computed tomography and magnetic resonance imaging of the head revealed no abnormalities. However, the Goldmann perimeter (GP) showed constriction of visual field in the left eye. Since traumatic optic neuropathy was suspected initially; therefore, two courses of methylprednisolone pulse therapy were administered. However, the BCVA and CFF gradually worsened to 20/200 and 14 Hz, respectively. Nevertheless, his pupillary light reflex was still normal, and GP showed a spiral visual field. Thus, we suspected that this was a case of FVL and performed bilateral randomized visual field testing using Imo vifa in three steps as a trick method. In the first step, we performed the normal method for bilateral randomized visual field testing. In the second and third steps, we explained to the patient that only the right or left eye would be examined on purpose; bilateral randomized visual field testing was then performed. The results of examinations revealed left homonymous hemianopsias and normal and concentric contraction of the visual field in both eyes. These results could not be explained by organic disease, and the patient was diagnosed with FVL.

Conclusions and Importance

Bilateral randomized visual field testing using Imo vifa with a trick method was useful for diagnosing FVL.

Functional hearing loss and developmental imbalances

OBJECTIVE

Functional hearing loss (FHL) is a disorder in which there are abnormal values on a hearing test, despite the absence of organic abnormalities in the peripheral and central auditory pathways. Here, we examined the developmental characteristics of FHL and the importance of intervention by analyzing the clinical characteristics of children with this disorder.

METHODS

We retrospectively examined 16 patients assessed under a diagnosis of FHL. After interventions such as psychological counseling by our pediatrics and psychiatry departments, we compared the clinical profiles of patients in which hearing was "improved/normalized" and "unimproved".

RESULTS

Fourteen patients visited a pediatrician and two chose not to do so. A discrepancy between the maximum and minimum values of the four index scores was observed in all patients in which WISC-IV (the fourth version of the Wechsler Intelligence Scale for Children) was performed (n = 12). The discrepancy between the verbal comprehension index (VCI) and perceptual reasoning index (PRI) was significantly greater in "unimproved" patients than in "improved/normalized" patients. Hearing improved, or was normalized, after intervention in six of 16 patients.

CONCLUSIONS

Developmental imbalances were suspected in all 12 children who visited a pediatrician and completed the WISC-IV. Cooperation with pediatricians, psychiatrists, and other health professionals is desirable in supporting patients diagnosed with FHL.

Pediatric Functional Neurologic Disorders

Functional neurologic disorders are common in the pediatric population. Recently, there has been a renewed focus on functional neurologic disorders, leading to improvements in diagnosis and management. This review focuses on updates in clinical presentation, diagnosis, pathophysiology (including neuroimaging), and treatment of functional neurologic disorders in the pediatric population.

Oblique multi-periscopic prism for field expansion of homonymous hemianopia

Oblique Fresnel peripheral prisms have been used for field expansion in homonymous hemianopia mobility such as walking and driving. However, limited field expansion, low image quality, and small eye scanning range limit their effectiveness. We developed a new oblique multi-periscopic prism using a cascade of rotated half-penta prisms, which provides 42° horizontal field expansion along with 18° vertical shift, high image quality, and wider eye scanning range. Feasibility and performance of a prototype using 3D-printed module are demonstrated by raytracing, photographic depiction, and Goldmann perimetry with patients with homonymous hemianopia.

Characteristics of 110 Patients With Functional Visual Loss

PURPOSE

Functional visual loss (FVL) is characterized by complaints of visual impairment without evidence of an organic cause. Physicians are often reluctant to diagnose FVL; thus, little is known about health care utilization in patients with FVL.

DESIGN

Retrospective case series.

METHODS

A total of 110 patients seen at 2 university-affiliated neuro-ophthalmology practices who were diagnosed with FVL were included. Medical records were evaluated, and data were collected on demographics, clinical presentation, ophthalmologic examination, neuroimaging, ancillary tests, and other health care provider visits and treatments.

RESULTS

More than 70% of patients with FVL were women with a mean age of 37 ± 15 years. The presenting complaint in 71.8% (79/110) of participants was decreased vision, which was bilateral in >50% of cases. Close to half (53/110) endorsed at least 1 coexisting psychiatric or neurologic diagnosis. The mean number of different medical specialists seen before neuro-ophthalmic consultation was 3.7 ± 2.6, and the average number of health care visits was 4.6 ± 4.4. Each patient had 2.2 ± 1.8 neuroimaging studies performed. Fifteen percent of patients underwent unnecessary treatments, including receiving steroids, visual therapy, and prisms.

CONCLUSIONS

Patients with FVL typically see at least 3 different health care providers across 4 different visits and undergo at least 2 neuroimaging studies before having neuro-ophthalmic consultation. To avoid this undue burden on patients and the health care system, clinicians should refer patients with suspected FVL to a neuro-ophthalmologist to confirm the diagnosis of FVL and appropriately counsel the patient.

Management of Functional Vision Disorders

PURPOSE OF REVIEW

The purpose of this review is to summarize current approaches to management of functional vision disorder (FVD).

RECENT FINDINGS

Several retrospective studies of FVD in both adults and children have shed light on the range of outcomes and the prevalence of psychosocial stressors among FVD patients. While the first line of treatment for FVD is reassurance and education, recent case reports highlight the use of additional treatment modalities including psychotherapy, hypnosis, and transcranial magnetic stimulation in specific cases. Although the epidemiology and diagnosis of functional vision disorder are well described, there is limited evidence supporting treatment modalities. Nevertheless, the majority of patients improve with conservative management including reassurance, education, and appropriate follow-up. Additional approaches such as mental health care referral can be considered in refractory cases.

Clinical approach to vision loss: a review for general physicians

Visual loss describes temporary or permanent reduction in visual acuity and/or field. Its aetiology is diverse due to the contributions of the different neuro-ophthalmic structures (eye, optic nerve, and brain) to image formation and perception, but may be categorised into ocular causes (corneal, lenticular, vitreoretinal and macular) or optic neuropathies. Clinical evaluation of visual loss relies on thorough history and examination to guide further tests. In this article, we provide a practical overview of visual loss assessment for general physicians.

Functional vision disorders in adults: a paradigm and nomenclature shift for ophthalmology

Vision loss with clinical findings that are incompatible with the symptoms and recognized neurological or ophthalmic conditions is a common presentation of patients to neurologists, ophthalmologists, and neuro-ophthalmologists. The accepted terminology to describe such patients has evolved over time, including functional visual disorder (FVD), non-organic vision loss, non-physiologic vision loss, functional vision loss, psychogenic, psychosomatic, and medically unexplained visual loss. Likewise, attitudes and recommended management options have changed over the years in the fields of psychiatry and neurology. FVD is a diagnosis of inclusion, and it is critical that the diagnosis be made and delivered efficiently and effectively to reduce patient and physician duress. We review the current Diagnostic and Statistical Manual (DSM V) terminology and the prior literature on FVD and describe how the approaches to diagnosis and management have changed. We provide recommendations on the appropriate techniques and diagnostic approach for patients with FVD. We also propose a protocol for consistent and standardized discussion with the patient of the diagnosis of FVD. We believe that the adoption of FVD as both a paradigm and nomenclature shift in ophthalmology will improve patient care.

Colour Vision Disorder due to Conversion Disorders in Childhood

BACKGROUND

Non-organic vision loss can manifest in various ways, most commonly in the form of reduced vision and visual field defects. Colour vision disorders in the context of a conversion disorder have only rarely been reported.

MATERIALS AND METHODS

This review presents the case of a 9-year-old boy with a colour vision disorder as the isolated symptom of a conversion disorder. The challenging in this case was an additional somatic comorbidity - a congenital red-green deficiency. Consequently it was difficult to make a diagnosis and to convince the parents.

CONCLUSION

It is important to rule out organic causes and establish the diagnosis of a conversion disorder. In these cases, multidisciplinary treatment is crucial for a successful outcome. The diagnosis may be especially challenging when the patients have both somatic and psychogenic complaints.

Acute bilateral loss of vision as organic manifestation of repressed psychological stress: A case report

Comprehensive clinical assessment with integrated team approach is crucial in managing cases of non-organic visual loss. Apart from pharmacotherapy, psychosocial rehabilitation should also be adequately addressed.

Occupational therapy consensus recommendations for functional neurological disorder

BACKGROUND

People with functional neurological disorder (FND) are commonly seen by occupational therapists; however, there are limited descriptions in the literature about the type of interventions that are likely to be helpful. This document aims to address this issue by providing consensus recommendations for occupational therapy assessment and intervention.

METHODS

The recommendations were developed in four stages. Stage 1: an invitation was sent to occupational therapists with expertise in FND in different countries to complete two surveys exploring their opinions regarding best practice for assessment and interventions for FND. Stage 2: a face-to-face meeting of multidisciplinary clinical experts in FND discussed and debated the data from stage 1, aiming to achieve consensus on each issue. Stage 3: recommendations based on the meeting were drafted. Stage 4: successive drafts of recommendations were circulated among the multidisciplinary group until consensus was achieved.

RESULTS

We recommend that occupational therapy treatment for FND is based on a biopsychosocial aetiological framework. Education, rehabilitation within functional activity and the use of taught self-management strategies are central to occupational therapy intervention for FND. Several aspects of occupational therapy for FND are distinct from therapy for other neurological conditions. Examples to illustrate the recommendations are included within this document.

CONCLUSIONS

Occupational therapists have an integral role in the multidisciplinary management of people with FND. This document forms a starting point for research aiming to develop evidence-based occupational therapy interventions for people with FND.

Application of Hemifield Visual Electrophysiology to Diagnose Functional Vision Loss

Neuro-ophthalmologists frequently see patients who are experiencing vision loss not accounted for by a neuro-ophthalmic disorder. In this article, we describe a case of binasal hemianopia in an otherwise healthy 65-year-old woman who was initially diagnosed with glaucoma but ultimately proved to have functional visual loss. This diagnosis was made by confirming by confirming normal visual pathway function using hemifield visual-evoked potential studies.

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.

Explicit and Implicit Components of the Emotional Processing in Non-organic Vision Loss: Behavioral Evidence About the Role of Fear in Functional Blindness

Non-organic vision loss (NOVL), a functional partial or global vision loss, might be considered a manifestation of conversion disorder. The few previous studies focused on investigating the relationship between cerebral activity and subjective symptoms in NOVL; however, the emotional processing is still neglected. In the present case-controls study, we investigated the capability of two individuals diagnosed with NOVL to recognize implicitly the emotions of fear and anger; this was assessed through a facial emotion recognition task based on the redundant target effect. In addition, the level of alexithymia was measured by asking them to judge explicitly their ability to identify and describe emotions. Both individuals showed selective difficulties in recognizing the emotion of fear when their performance was contrasted with a matched control sample; they also mislabeled other emotional stimuli, judging them as fearful, when they were not. However, they did not report alexithymia when measured using a standard questionnaire. This preliminary investigation reports a mismatch between the implicit (i.e., the behavior in the experimental paradigm) and the explicit (i.e., the subjective evaluation of one’s own emotional capability) components of the emotional processing in NOVL. Moreover, fear seems to represent a critical emotion in this condition, as has been reported in other psychiatric disorders. However, possible difficulties in the emotional processing of fear would emerge only when they are inferred from an implicit behavior, instead of a subjective evaluation of one’s own emotional processing capability.

Analysis of Visual Field Defects Obtained with Semiautomated Kinetic Perimetry in Patients with Leber Hereditary Optic Neuropathy

Purpose

To analyse visual field (VF) defects obtained using semiautomated kinetic perimetry (SKP) in patients suffering from Leber hereditary optic neuropathy (LHON).

Methods

Twenty-two eyes of eleven consecutive LHON male patients with confirmed mitochondrial 11778G>A DNA mutation were prospectively examined with the V4e stimulus of SKP in both eyes. The mean time after the onset of LHON was one year. The area of obtained isopters was measured in square degrees (deg²). Additionally, static automated perimetry (SAP) within 30° was performed.

Results

Visual acuity ranged from counting fingers to 50 cm to 0.4. VFs obtained with SKP showed central scotomas in 18 eyes (82%); the periphery of the VF in these eyes remained intact. The mean area of central scotoma was 408.8 deg², and the mean area of the peripheral VF was 12291.1 deg²; SAP also revealed central scotoma in these patients. In four eyes (18%) with the worst visual acuity, only the residual central island of VF was found using SKP (mean area 898.4 deg²). SAP was difficult to obtain in these patients.

Conclusions

SKP provides additional clinical information in regard to the visual function of LHON patients. SKP enables the quantification of the area of central scotoma, preserved peripheral VF, and residual central island of vision. Using V4 stimulus is especially useful in LHON patients with poor visual acuity, when SAP is difficult to obtain.

Non-organic Vision Loss in the Afghanistan and Iraq Conflicts

Non-organic visual loss (NOVL), defined as a decrease in visual acuity or field without an identifiable organic cause, can be challenging to diagnose, especially in patients whose NOVL is superimposed on some component of true organic pathology. Exposure to combat puts soldiers at risk of emotional distress and physical trauma, which can contribute to the development of NOVL with conversion disorder or malingering. This case series describes six patients with NOVL who sustained ocular or non-ocular injuries while serving in combat operations in Iraq and Afghanistan, and highlights diagnostic pearls and components of inter-disciplinary management in the unique military context.

Postoperative visual loss due to conversion disorder after spine surgery: a case report

Background and objective

Case report

Conclusions

[Testing and approach when non-organic visual loss is suspected]

Approximately 5% of the patients in the ophthalmological practice suffer from non-organic vision loss. In children non-organic vision loss has been observed from the age of 6 years. In order to be able to make a rapid diagnosis knowledge of the relevant clinical tests is decisive. If a patient shows signs of non-organic visual loss, diagnostic externalization of the visual function is crucial. Depending on the symptoms there are various tests, which can be used to differentiate between organic and non-organic disorders. For therapeutic and economic reasons an early diagnosis of a non-organic visual loss is crucial. Ophthalmologists need to differentiate between malingering and augmentation, where the patient is aware of the fraud and tries to gain personal benefit from it, and somatoform disorders. In the latter, a more sensitive approach is recommended.

An atypical presentation of functional visual loss: A case report

RATIONALE

Functional visual loss (FVL) can manifest as various symptoms. Decreased distant visual acuity is the most common symptom and visual field defect is the second most common symptom. Hemianopsia is rarely reported. In an atypical situation of FVL, it is important to prove that no organic pathology exists, through detailed history taking and appropriate examinations.

PATIENT CONCERNS

This review presents the case of a 48-year-old male patient presented with decreased bilateral visual acuity and visual field defect after a traffic accident 3 weeks ago. Visual field test showed atypical features of FVL in which visual field change from binasal hemianopsia to left homonymous hemianopsia.

DIAGNOSIS

The best corrected visual acuities (BCVA) were 20/63 in both eyes and binasal hemianopsia was observed on a Humphrey visual field test. Brain computed tomography (CT) scan and magnetic resonance imaging (MRI) showed no abnormalities in the brain and optic chiasm. Two weeks after presentation, however, the patient's visual field defect changed from binasal hemianopsia to left homonymous hemianopsia. We diagnosed it as FVL due to conversion disorder.

INTERVENTION AND OUTCOMES

We decided to cooperate with a psychiatrist for cognitive behavioral therapy and the patient is under observation.

LESSONS

Binasal hemianopsia and homonymous hemianopsia are rare; however, it may occur simultaneously in 1 patient with FVL. The possibility of FVL should be considered when there is atypical visual field defect and no organic abnormalities are observed. Repeated Humphrey field test and VEP may be helpful in diagnosis of FVL.

Postoperative transient blindness after general anesthesia and surgery: case report of conversion disorder

Postoperative acute visual loss due to organic pathology has been described after spinal surgery in the prone position. This report describes a case of transient postoperative blindness in a patient after general anesthesia and surgery in the prone position. Postoperative workup did not reveal any organic pathology. Unbeknown to the treating physicians, the patient had a comorbid untreated psychiatric history. Upon psychiatric consultation, the patient was diagnosed with conversion disorder as a cause of postoperative blindness. There was full recovery of vision after psychiatric intervention within a week.

High-Power Prismatic Devices for Oblique Peripheral Prisms

Purpose

Horizontal peripheral prisms for hemianopia provide field expansion above and below the horizontal meridian; however, there is a vertical gap leaving the central area (important for driving) without expansion. In the oblique design, tilting the bases of both prism segments toward the horizontal meridian moves the field expansion area vertically and centrally (closing the central gap) while the prisms remain in the peripheral location. However, tilting the prisms results also in a reduction of the lateral field expansion. Higher prism powers are needed to counter this effect.

Methods

We developed, implemented, and tested a series of designs aimed at increasing the prism power to reduce the central gap while maintaining wide lateral expansion. The designs included inserting the peripheral prisms into carrier lenses that included yoked prism in the opposite direction, combination of two Fresnel segments attached at the base and angled to each other (bi-part prisms), and creating Fresnel prism–like segments from nonparallel periscopic mirror pairs (reflective prisms).

Results

A modest increase in lateral power was achieved with yoked-prism carriers. Bi-part combination of 36Δ Fresnel segments provided high power with some reduction in image quality. Fresnel reflective prism segments have potential for high power with superior optical quality but may be limited in field extent or by interruptions of the expanded field. Extended apical scotomas, even with unilateral fitting, may limit the utility of very high power prisms. The high-power bi-part and reflective prisms enable a wider effective eye scanning range (more than 15 degrees) into the blind hemifield.

Conclusions

Conventional prisms of powers higher than the available 57Δ are limited by the binocular impact of a wider apical scotoma and a reduced effective eye scanning range to the blind side. The various designs that we developed may overcome these limitations and find use in various other field expansion applications.

Functional and simulated visual loss

Nonorganic visual loss (NOVL) is the cause of a large number of referrals to neurologists and ophthalmologists and is a frequent area of overlap between neurologists, ophthalmologists, and psychiatrists. NOVL is the presence of visual impairment without an organic cause for disease despite a thorough and comprehensive investigation. A diagnosis of NOVL requires both the absence of any findings on examination and proof of the integrity and functioning of the visual system. Although sometimes a challenging diagnosis to make, there are a number of techniques and maneuvers which can be utilized fairly easily, either at the bedside or in the clinic, to help determine if a patient has NOVL. In some instances specialized testing, such as formal visual field testing, optical coherence tomography, visual evoked responses, electroretinogram, and various imaging modalities (magnetic resonance imaging) are performed to help determine if the cause of visual loss is organic or nonorganic. Once a diagnosis of NOVL is made, treatment centers around reassurance of the patient, close follow-up, and, if necessary, referral to a psychiatrist, as these patients may have underlying psychiatric disorders and a preceding strong emotional event leading to the current symptoms, and may be more likely to develop depression and anxiety.

Bilateral Concurrent Eye Examination with a Head-Mounted Perimeter for Diagnosing Functional Visual Loss

The authors here report a case series where bilateral concurrent eye examination, using a head-mounted perimeter (imo®), was employed to facilitate diagnosis of functional visual loss, as regular ophthalmological tests were ineffective. Subjects (11-year-old female, 15-year-old male, and 24-year-old male) were diagnosed with unilateral functional visual loss by using the imo®, at the Kitasato University hospital. The results of the imo® and those of Goldmann perimetry or Humphrey Field Analyzer II differed for all subjects, which is indicative of potential functional visual loss. Bilateral concurrent examination with the imo® may become a standard for future diagnosis of unilateral functional visual loss.

[Postoperative visual loss due to conversion disorder after spine surgery: a case report]

BACKGROUND AND OBJECTIVE

Patients undergoing spinal surgeries may develop postoperative visual loss. We present a case of total bilateral visual loss in a patient who, despite having clinical and surgical risk factors for organic lesion, evolved with visual disturbance due to conversion disorder.

CASE REPORT

A male patient, 39 years old, 71kg, 1.72 m, ASA I, admitted to undergo fusion and discectomy at L4-L5 and L5-S1. Venoclysis, cardioscopy, oximetry, NIBP; induction with remifentanil, propofol and rocuronium; intubation with ETT (8.0mm) followed by capnography and urinary catheterization for diuresis. Maintenance with full target-controlled intravenous anesthesia. During fixation and laminectomy, the patient developed severe bleeding and hypovolemic shock. After 30minutes, hemostasis and hemodynamic stability was achieved with infusion of norepinephrine, volume expansion, and blood products. In the ICU, the patient developed mental confusion, weakness in the limbs, and bilateral visual loss. It was not possible to identify clinical, laboratory or image findings of organic lesion. He evolved with episodes of anxiety, emotional lability, and language impairment; the hypothesis of conversion syndrome with visual component was raised after psychiatric evaluation. The patient had complete resolution of symptoms after visual education and introduction of low doses of antipsychotic, antidepressant, and benzodiazepine. Other symptoms also regressed, and the patient was discharged 12 days after surgery. After 60 days, the patient had no more symptoms.

CONCLUSIONS

Conversion disorders may have different signs and symptoms of non-organic origin, including visual component. It is noteworthy that the occurrence of this type of visual dysfunction in the postoperative period of spinal surgery is a rare event and should be remembered as a differential diagnosis.

As long as you've got your health: Longitudinal relationships between positive affect and functional health in old age

OBJECTIVE

Reciprocal relationships between positive affect (PA) and health are now subject of a heuristic debate in psychology and behavioral medicine. Two radically opposed approaches address the link between subjective well being (SWB) and physical health: top-down (i.e., psychosomatic hypothesis) and bottom-up (i.e., disability/ability hypothesis) approaches. The aim of the present study was to test these two approaches by investigating thirteen-year longitudinal relationships between PA, as an affective dimension of SWB, and functional health in older people.

METHODS

The study included 3754 participants aged 62-101 years assessed 6 times over a thirteen-year period. PA was measured by the mean of the positive affect subscale of the CES-D scale. Functional health was assessed by four composite items: a single-item self-rating of hearing impairment, a single-item self-rating of vision impairment, the number of medically prescribed drugs, and a single-item self-rating of dyspnoea. We used cross-lagged modeling with latent variables, which is appropriate for testing specific theories. Mean arterial pressure, diabetes mellitus and hypercholesterolemia status, sequelae of stroke, gender, level of education, and age at baseline were use as control variables in the models.

RESULTS

Results indicated that good health significantly predicted subsequent levels of PA (average β = -0.58, p < 0.001), but PA did not predict subsequent levels of good health (β = 0.01, ns).

CONCLUSION

This finding, obtained from a sample of older people, is in keeping with the bottom-up approach, and supports the popular adage "As long as you've got your health". Limitations of this finding are reviewed and discussed. Models including longitudinal mediators, such as biomarkers and life style patterns, are needed to clarify the nature of the link between these constructs.

Validity assessment and the neurological physical examination

BACKGROUND

The assessment of any patient or examinee with neurological impairment, whether acquired or congenital, provides a key set of data points in the context of developing accurate diagnostic impressions and implementing an appropriate neurorehabilitation program. As part of that assessment, the neurological physical exam is an extremely important component of the overall neurological assessment.

PURPOSE

In the aforementioned context, clinicians often are confounded by unusual, atypical or unexplainable physical exam findings that bring into question the organicity, veracity, and/or underlying cause of the observed clinical presentation. The purpose of this review is to provide readers with general directions and specific caveats regarding validity assessment in the context of the neurological physical exam.

CONCLUSIONS

It is of utmost importance for health care practitioners to be aware of assessment methodologies that may assist in determining the validity of the neurological physical exam and differentiating organic from non-organic/functional impairments. Maybe more importantly, the limitations of many commonly used strategies for assessment of non-organicity should be recognized and consider prior to labeling observed physical findings on neurological exam as non-organic or functional.

Tests for malingering in ophthalmology

Simulation can be defined as malingering, or sometimes functional visual loss (FVL). It manifests as either simulating an ophthalmic disease (positive simulation), or denial of ophthalmic disease (negative simulation). Conscious behavior and compensation or indemnity claims are prominent features of simulation. Since some authors suggest that this is a manifestation of underlying psychopathology, even conversion is included in this context. In today's world, every ophthalmologist can face with simulation of ophthalmic disease or disorder. In case of simulation suspect, the physician's responsibility is to prove the simulation considering the disease/disorder first, and simulation as an exclusion. In simulation examinations, the physician should be firm and smart to select appropriate test(s) to convince not only the subject, but also the judge in case of indemnity or compensation trials. Almost all ophthalmic sensory and motor functions including visual acuity, visual field, color vision and night vision can be the subject of simulation. Examiner must be skillful in selecting the most appropriate test. Apart from those in the literature, we included all kinds of simulation in ophthalmology. In addition, simulation examination techniques, such as, use of optical coherence tomography, frequency doubling perimetry (FDP), and modified polarization tests were also included. In this review, we made a thorough literature search, and added our experiences to give the readers up-to-date information on malingering or simulation in ophthalmology.

Unrecognized and unregistered blindness in people 70 or older in Jing'an district, Shanghai, China

AIM

To evaluate the efficacy of a registration system for the blind people and to monitor the blindness due to uncorrected refractive error and cataract in Jing'an district, Shanghai, China.

METHODS

Five hundred and ten blind people, based on visual acuity screening in a population aged 70 or older were enrolled into the study. Four hundred and forty subjects were interviewed. The following data were collected on each patient: demographic data, number of hospital visits for eye related problems, distance visual acuity, visual fields, ophthalmic diagnoses, education and registration status. If the eligible subject was not registered as blind, the reason for non-registration was recorded.

RESULTS

Ten point nine one percent blindness was due to cataract, 27.5% due to uncorrected refractive error, and only 61.59% met the eligible blindness criteria (uncorrected refractive error and cataract are not considered as eligible blindness). The first four leading causes of eligible blindness were age related macular degeneration (25.09%), myopic macular degeneration (21.40%), glaucoma (18.82%) and corneal disease (8.12%). Only 68.27% eligible blind people were registered. The patients with macular degeneration and glaucoma tended not to register. Blind people with an above primary school education were 2.59 times more likely to be registered than those who were illiterate or had only a primary school education (OR=2.59, 95%CI: 1.49-4.48, P<0.01). Patients who had 4 or more visits to the hospital requesting eye care services in a year were 2.2 times more likely to be registered than those with less than 4 visits to the hospital (OR=2.54, 95%CI: 1.47-4.38, P<0.001). The first two leading reasons of misregistration were unknowing the registration system (48%) and unwilling to register (21%).

CONCLUSION

Under-registration of the eligible blind people exists in the registry system. Education and the number of hospital visits for eye care services were factors associated with registration levels. Uncorrected refractive error and cataract are important causes of blindness.

The blind photographer. Observations on the bewildering nature of feigned vision loss

The diagnosis of feigned vision loss in adults taxes the doctor-patient relationship because the relationship should be based on trust, honesty, and the mutual desire to improve the medical condition. Even under ideal circumstances, physicians rarely have a complete understanding of the factors that lead patients to simulate disease they do not have. We describe the historical figure of John Howard Griffin (1920-1980) who likely perpetuated feigned vision loss for a decade. His writings provide a unique perspective on motivation (or inspiration) behind factitious disease.

Approach to the patient with acute monocular visual loss

Acute visual loss in one eye is a common symptom brought to the attention of the practicing neurologist. In this circumstance, it is critical to identify whether visual loss is due to an optic neuropathy or an ocular disorder (especially retinal disease). This review addresses the elements of the history and examination that are useful in evaluating a patient with visual loss, with the goals of correctly localizing the lesion and constructing a likely differential diagnosis.

Shedding light on photophobia

Photophobia is a common yet debilitating symptom seen in many ophthalmic and neurologic disorders. Despite its prevalence, it is poorly understood and difficult to treat. However, the past few years have seen significant advances in our understanding of this symptom. We review the clinical characteristics and disorders associated with photophobia, discuss the anatomy and physiology of this phenomenon, and conclude with a practical approach to diagnosis and treatment.