Development Of Visual Symptoms Research Articles

Intractable hiccups, nausea, and vomiting, an unnerving cause of vision loss

Acute optic neuritis (ON) is caused by variety of complex disorders that can be differentiated with the help of history, radiology, and serology. Identification of nonneurological symptoms that occur before the demyelinating event aids in timely diagnosis and prevention of further neurological attacks. We describe a case of unilateral ON with a history of intractable hiccups, nausea, and vomiting, wherein the possibility of area postrema syndrome (APS) was overlooked until the development of visual symptoms. APS recently identified as a hallmark of neuromyelitis optica spectrum disorder is a rare neurologic cause of gastrointestinal symptoms. This atypical presentation of APS results from autoantibodies directed against the aquaporin-4 rich sites, such as area postrema. This case brings to light the importance of eliciting history of intractable hiccups, nausea, and vomiting in a patient with ON. Despite being a commonly encountered symptom, it may rarely raise a suspicion for neuromyelitis optica.

Acute angle closure glaucoma - A potential blind spot in critical care.

We report a case of a 69-year-old gentleman who developed an acutely painful eye with loss of visual acuity whilst on the critical care unit. He was admitted three days previously with an infective exacerbation of chronic obstructive pulmonary disease requiring invasive mechanical ventilation. In addition, he received intravenous antibiotics, steroids, nebulised bronchodilators and intravenous aminophylline, together with noradrenaline for blood pressure support. On development of visual symptoms, an emergency ophthalmology review diagnosed acute angle closure glaucoma. Treatment with pilocarpine eye drops, intravenous acetazolamide and bilateral YAG laser iridotomies provided immediate symptom relief and he went on to make an excellent recovery. Acute angle closure glaucoma is a potentially devastating ophthalmic emergency. Critical care patients are at particular risk for the development of this condition due to the use of predisposing medications, such as sympathomimetics and beta agonists. Sedated patients also run a risk of delayed diagnosis so a high index of suspicion is required.

VISUAL DISTURBANCES IN PARKINSON’S DISEASE PATIENTS

Along with the motor symptoms, Parkinson’s disease (PD) patients experience a wide range of non-motor problems including visual disturbances. These are multifaceted, but often underreported as such. In a visual survey questionnaire, 78% PD patients reported at least one problem related to vision or visuospatial functioning. The most frequent encountered problems are impaired contrast sensitivity, color discrimination, visuospatial processing, ocular or eyelid movements and diplopia followed by visual misperceptions and hallucinations. Some patients report dry eyes, ocular pain or photophobia. The pathophysiological basis of the visual disturbances is not completely understood. Changes in the visual cortex were detected with functional MRI before the visual symptoms were clinically evident. Further studies are necessary to determine how these changes will contribute to development of visual symptoms in PD patients. Other authors consider a dopaminergic deficit in the retina to be responsible for some of these symptoms, being known that dopamine is the major neurotransmitter in the amacrine and interplexiform cells in the retina. Visual hallucinations are likely to be a result of disruption across related yet diverse neural circuitry. The therapy is only symptomatic and not always satisfactory. It includes ophthalmological treatment and specific treatment for hallucinations. Optical Coherence Tomography (OCT) is a new investigation method who offers quantitative morphology of gross retinal histology. The thinning of the peripapillary retinal nerve fiber layer was observed in PD. Some studies mentioned that macular thickness measured by the OCT could be a promising biomarker of PD. This work shows how complex the visual problems in PD patients can be and the importance of a thorough and multidisciplinary approach.

RESULTS FROM SURVEY ON RESISTANCE OF PLUM CULTIVAR 'JOJO' TO PLUM POX VIRUS

The aim of this study was to evaluate the reaction of plum cultivar ‘Jojo’ to Plum pox virus (PPV) infection by combination of biological indexing with PPV-M, -D and -Rec strain isolates and field observations in Bulgarian commercial orchards, planted with ‘Jojo’, under the agro-biological conditions of three locations of the Plovdiv region. Development of visual symptoms on the field grown trees’ leaves and fruits was monitored during three successive vegetative cycles (2010-2012). PPV presence in plant tissues was detected by enzyme-linked immunosorbent assay (ELISA) and immune capture-reverse transcription-polymerase chain reaction (IC-RT-PCR). The biological indexing experiment showed that initially small chlorotic spots developed on the leaves of the inoculated plants that turned brownish (hypersensitive reaction) later on, followed by falling of the necrotic tissues. In the field survey, similar symptoms of hypersensitivity were observed on the leaves of some ‘Jojo’ trees. Leaf samples from plants that manifested hypersensitive reaction (the inoculated plants and field growing trees) reacted negative with antiserums against PPV in ELISA and no amplification was obtained in IC-RT-PCR with the primer pair P1/P2 used. Several of the trees grown in the field showed some virus-like leaf symptoms, during the third vegetative period. Samples collected from these trees reacted negative for PPV in ELISA and none of the samples tested by IC-RT-PCR produced PPV-specific PCR products. However, the symptomatic trees reacted positive with antiserum against Prunus necroticc ring spot virus (PNRSV). No symptoms on the fruits of the inspected ‘Jojo’ trees were recorded. The results obtained suggest that ‘Jojo’ cultivar could be resistant to PPV infection, both in the experimental biological indexing and under the agro-biological conditions of the Plovdiv region of Bulgaria.

Effects of R gene‐mediated resistance in Brassica napus (oilseed rape) on asexual and sexual sporulation of Pyrenopeziza brassicae (light leaf spot)

The phenotype of the R gene‐mediated resistance derived from oilseed rape (Brassica napus) cv. Imola against the light leaf spot plant pathogen, Pyrenopeziza brassicae, was characterized. Using a doubled haploid B. napus mapping population that segregated for resistance against P. brassicae, development of visual symptoms was characterized and symptomless growth was followed using quantitative PCR and scanning electron microscopy on leaves of resistant/susceptible lines inoculated with suspensions of P. brassicae conidia. Initially, in controlled‐environment experiments, growth of P. brassicae was unaffected; then from 8 days post‐inoculation (dpi) some epidermal cells collapsed (‘black flecking’) in green living tissue of cv. Imola and from 13 to 36 dpi there was no increase in the amount of P. brassicae DNA and no asexual sporulation (acervuli/pustules). By contrast, during this period there was a 300‐fold increase in P. brassicae DNA and extensive asexual sporulation in leaves of the susceptible cv. Apex. However, when leaf tissue senesced, the amount of P. brassicae DNA increased rapidly in the resistant but not in the susceptible cultivar and sexual sporulation (apothecia) was abundant on senescent tissues of both. These results were consistent with observations from both controlled condition and field experiments with lines from the mapping population that segregated for this resistance. Analysis of results of both controlled‐environment and field experiments suggested that the resistance was mediated by a single R gene located on chromosome A1.

Effect of Computer Monitor Distance on Visual Symptoms and Changes in Accommodation and Binocular Vision

Visual symptoms are the most common complaints associated with prolonged computer use. We investigated effects of accommodation and vergence demands specified by the computer monitor viewing distance on the development of visual symptoms and visual function changes. Ten 18–35 year-old subjects performed a two-hour, visually demanding, text-viewing task at three viewing distances over three days. The visual angle of the character size was held constant. We measured changes in several static and dynamic properties of accommodation and binocular vision before and for 90 minutes after the viewing task. The 100 cm viewing distance induced less lead effect for accommodation to a distant target and less lag retention for accommodation to a near target. On the other hand, the viewing distance of 33 cm introduced less eye irritation or tearing symptoms and a higher overall dynamic convergence response compared to longer viewing distances. There were weak associations between changes in binocular functions and visual symptoms. While the symptoms were influenced by the viewing distance, they cannot be fully explained by the changes in the visual functions measured here.

Dementia with Lewy Bodies

In this case study, we describe the symptoms, neuropsychological testing, and brain pathology of a man with dementia with Lewy bodies. Dementia with Lewy bodies might be the second most common form of degenerative dementia in the elderly. Progressive cognitive decline, well-formed visual hallucinations, and parkinsonism are core features of this disease. This case was marked by preserved verbal expression despite impairment in memory, visuospatial skills, and attention span. Development of visual symptoms and parkinsonism occurred very early in the course of the disease.

Beech (Fagus sylvatica) response to ozone exposure assessed with a chlorophyll a fluorescence performance index

This paper describes a relationship between ozone exposure, biomass, visual symptoms and a chlorophyll a fluorescence performance index for young beech trees (Fagus sylvatica). The plants were exposed to four levels of ozone in open-top fumigation chambers (50, 85, 100% of ambient, and 50% of ambient+30 nl l−1 ozone) that fluctuated in parallel with ambient ozone during a single growing season. The trees were fumigated in the four treatments with ozone levels corresponding to an AOT40 (accumulated exposure above a threshold of 40 nl l−1) of 0.01, 3.35, 7.06 and 19.70 μl l−1 h, respectively. Highly significant differences were found between the 50% of ambient+30 nl l−1 ozone treatment and all other treatments, with a 70.5% reduction in primary photosynthetic performance, as measured with the PI index. The reduction of the PI values demonstrated a high correlation with visual symptom development (r2=0.98), and by the end of September with biomass loss (r2=0.99). A significant ozone exposure–response relationship was found between AOT40 and primary photochemistry (r2=0.97). Thus, analysis of PI provides an alternative method for regional monitoring of tree health within the context of the currently employed AOT40.

Avoiding Internal Breakdown of Stone Fruit by an “Off” the Tree Pre-ripening Treatment

During the past two seasons, the relationship between fruit ripening “ON” or “OFF” the tree and internal breakdown incidence was studied with `Elegant Lady' and `O'Henry' peach cultivars. Internal breakdown (IB) visual symptom development was delayed in fruit harvested at different physiological maturities and exposed to different “OFF” the tree pre-ripening treatments. As a follow up, different pre-ripening treatments (controlled delayed cooling) were tested for several peach, nectarine, and plum cultivars susceptible to IB. This pre-ripening treatment delayed flesh browning, mealiness, and off-fl avor development after a simulated shipment and retailer handling period for `Flavorcrest', `Elegant Lady', `O'Henry', `Parade', `Fairtime', `Carnival', `Prima Gattie', `Last Chance', `Autumn Gem', `Autumn Lady', and `Autumn Rose' peaches; `Summer Grand' and `September Red' nectarines; and `Fortune' plum. However, decay development may be a problem. Delayed cooling at 20°C must be carried out with fruit protected with fungicide and wax for the shortest possible, but still effective, length of time to limit IB. The temperature and the length of this pre-ripening treatment, and the presence or absence of ethylene during the delayed cooling is cultivar dependent. Thus, specific pre-ripening conditions must be developed for each cultivar.