Color Contrast Sensitivity Research Articles

Evaluation of relationship between color discrimination ability, stereoscopic acuity and contrast sensitivity in healthy individuals

Evaluation of relationship between color discrimination ability, stereoscopic acuity and contrast sensitivity in healthy individuals

Impact of Eyes and Visual Functions in Safe Driving

Driving is a high level of visual functions demanding occupation. The relationship of good visual function and driving safety are innately and unarguably linked and have a direct bearing on the incidence of road traffic accidents. A more practical approach to improve the efficacy of vision screening at licensure is to examine visual acuity screening test supplemented by other types of screening tests like contrast sensitivity, visual field, binocularity, color vision, processing speed, light and dark adaptation etc. These clinical tests have a large evidence basis for their relevance to driver safety and should be mandatory for obtaining and renewing the driving license. The individual who failed the initial screening should undergo a protocol based comprehensive evaluation by an Ophthalmologist or Optometrist if fit to drive in future. Visual acuity and other visual functions requirements for driving vary from country to country though most countries mandate visual acuity of 20/40 in the better eye with horizontal visual field of 120 degrees. But there is variation regarding provision of color vision, binocularity, contrast sensitivity and night vision tests. Nepal yet , has not strict rules regarding evaluation of visual functions for safe driving. But indeed, a local expert review board should determine the suitability to issue a normal driving license or a restricted driving license, a temporary or a permanent denial for those who partially or completely failed the vision specific requirements. Moreover appropriate modification of the existing laws and expedited implementation are mandatory to minimize visual functions related road traffic accidents which is an avoidable cause of mortality and morbidity.

Orbital Apex Syndrome With Encephalitis: A Rare and Serious Complication of Herpes Zoster Ophthalmicus

Introduction: Herpes zoster reactivation is more common in the elderly population. Although ocular complications are seen in 20-70% of patients with herpes zoster ophthalmicus, orbital apex syndrome is a rare case. Encephalitis is also a rare neurologic complication of HZO. Purpose: To report a Herpes Zoster Ophthalmicus (HZO)case with rare neurologic complication that ophthalmologist should be aware of. Case Presentation: A 68-year-old man had a chief complaint of a sudden blurred vision in right eye two days before admission, followed by rash and pain on the right upper eyelid and forehead. Visual acuity was hand movement on the right eye and 0.5 on the left eye. The patient had total ophthalmoplegia and total ptosis on his right eye, reverse relative afferent pupillary defect on his left eye and right peripheral facial nerve palsy. Optic discs were found to be normal on both eyes. The patient was diagnosed as orbital apex syndrome on his right eye associated HZO and right peripheral facial nerve palsy. The patient received oral acyclovir 800 mg five times/day and intravenous methylprednisolone 250 mg four times/day for three days. After four days of admission, the patient had a seizure and loss of his consciousness. The patient was consulted to neurology department and was given anticonvulsant therapy. The spinal tap revealed pleocytosis and increased protein. The patient was diagnosed as herpes zoster encephalitis. After one week, the patient regained full consciousness and his visual acuity was improved to 0.16 on the right eye. Color vision, visual field, and contrast sensitivity were also improved, ophthalmoplegia were partially resolved and peripheral facial nerve palsy was fully resolved. Conclusion: Herpes Zoster Ophthalmicus affect the central and peripheral nervous system at the same time and can be life-threatening with delayed diagnosis and treatment. It may be necessary to collaborate with the neurology department for every HZO case to minimize the life-threatening complications of HZO.

Effects of blunt trauma of eye on retinal nerve fibre layer

AIM: To study the effects of blunt trauma of eye on visual acuity and retinal nerve fiber layer (RNFL). METHODS: A prospective observational study was done on the patients of a road traffic accident (RTA) having blunt trauma injury of the eye from august 2018 to July 2019 at the Department of Ophthalmology, Hind Institute of Medical Sciences, Barabanki. Patients between the age group of 20 to 65 years undergoing RTA with ocular complaints were included in this study. Colour vision, contrast sensitivity, and best-corrected visual acuity (BCVA) were recorded, RNFL analysis was done through OCT. RESULTS: A total of 108 patients were enrolled in this study and were grouped as 54 cases and 54 controls. The mean age was 43±2.3 years with 11 (20.37%) females and 43 (79.6%) males in the case group. At initial visit after RTA, the difference between color vision, contrast sensitivity and BCVA between right and left eyes of cases and controls were significant. After a follow up of 3mo only significant difference was noted in contrast sensitivity between cases and control groups. Change in color vision and BCVA after 3mo was insignificant. Similarly, an initial significant difference was noted in mean RNFL thickness between cases and control groups, but after follow up of 3mo mean RNFL thickness difference was significant only in superior and temporal quadrants. CONCLUSION: RTA or blunt trauma of eye can lead to persistent RNFL thinning and decreased visual function.

Clinical profile and visual outcome of optic neuritis patients in tertiary care hospital

To study the clinical profile and visual outcome of optic neuritis Study population included patients who were clinically diagnosed as Optic neuritis at Department of Ophthalmology, Mamata medical college. A total of 30 cases were taken up for the study. Patients were examined in detail at presentation and treated with ONTT regimen and follow up done at 1 week, 1 month and 3 months.Most common age group affected was 20- 50 years with mean of 39.36yrs. Highest incidence was seen in age group of 41-50yrs which was found to be 36.7%. Higher incidence was seen in females. Females constituted 63.33%. Female to Male ratio was 1.72:1. Higher incidence of Papilitis was seen among males and RBN was more commonly seen among females. Incidence of retrobubar neuritis was slightly higher than papilitis. All presented with DOV. Pain was present in 56.66%. Loss of vision persisted more than 1 month in case of papilitis. BCVA after ONTT had very good improvement. After treatment majority had vision between 6/18-6/6 (46.38%) and was statistically significant. Also after 1month and 3 months majority had vision between 6/18-6/6 [60.52% and 64.56% respectively]. Only 3.23% had VA less than 6/60 after 3months. There was improvement in both colour vision and contrast sensitivity but was not statistically significant. Central and centrocaecal scotoma was most common visual field defect. MRI brain was done in only 11 patients due to financial constraints which revealed two MS and 3 cases of increased signal intensity in short segment of Optic nerve. The recurrence rate in our study was 6.66%.The clinical profile of ON in Indian patients is different from that in the Western population. Unlike reported in the Western literature, Papillitis is as frequent as Retrobulbar neuritis in the Indian setup, with poorer visual outcome.

Visual function recovery post decompression surgery in meningioma: a case report

Background: Meningiomas represent about 20% of intracranial tumors. Due to these tumors' proximity to the optic nerve, typically progressive unilateral vision loss, over several months to years, is the classic clinical presentation.Case Presentation: A 23 y.o. male presented with a progressive monocular visual loss of the right eye since 4 months. Visual acuity on the right eye was 1/300 and 6/6 on the left eye. Color vision and contrast sensitivity of the left eye was excellent. Fundus examination showed papilledema on right eye and left eye was within normal limit. MRI reveals a strong enhancing mass along the right and left sphenoid wing, measuring approximately 3.9 x 5.5 x 3.3 cm, extending into the parasellar region, compressing optic chiasm and encasing right and left N.III, N.IV and N.V. Patient were diagnosed with compressive optic neuropathy on the right eye due to meningioma. Following the decompression surgery, visual acuity on the right eye improved to 6/24, color vision 25/38 and contrast sensitivity was 5%. The patient was discharged 4 days after surgery and scheduled for routine follow-up at the polyclinic.Conclusion: Vision loss due to the compressive effect of meningioma may be reversible. The severity and the duration of vision loss due to compression may affect the final visual recovery. Early detection and prompt multidisciplinary approach are necessary to obtain a better outcome.

Effect of blue-blocking lenses on colour contrast sensitivity

ABSTRACT Clinical relevance There is a significant unintended consequences of blue‐blocking lenses on visual behaviour, particularly for the detection of colour. Optometrists need to be mindful of this when prescribing the appropriate blue‐blocking lenses for individuals who work in environments in which blue light is prevalent. Background The selective reduction in visible wavelengths transmitted through commercially available blue‐blocking lenses is known to influence object appearance and luminance contrast, and also potentially object colour contrast. The present study investigated the effect of a number of commercially available blue‐blocking lenses on colour contrast sensitivity in normal individuals under low and high contrast stimulus conditions. Methods Five healthy participants (one man and four women), aged between 23 and 39-years, were recruited for this study. Crizal Prevencia (Essilor), Blue Guardian (Opticare), and Blu‐OLP (GenOp) lenses were examined in this study in comparison to a control lens (clear lens without blue‐filtering coating). In Experiment 1, colour contrast thresholds were measured using a visual search colour detection task in which the colour (CIE Lu'v' red, green, blue and yellow) of the target circle stimulus (randomly located in an annulus of achromatic circles) was systematically reduced using a staircase procedure. As blue‐blocking lenses selectively block blue light, in Experiment 2, colour contrast thresholds were specifically quantified for a range of short wavelengths near the attenuation transmittance range of the blue‐blocking lenses tested. Results Experiments 1 and 2 showed that colour contrast was impaired only for blue colours, and this was most evident at low contrasts. Additionally, the blue‐blocking lenses with lower transmittance profiles led to greater reductions in colour contrast sensitivity and shown to affect colour contrast thresholds. Conclusion Our results suggest that while reducing blue light potentially minimises the harmful effect of blue hazard light, blue‐blocking lenses can unintentionally reduce colour contrast sensitivity, particularly at low light levels.

Visual-stimuli Four-arm Maze test to Assess Cognition and Vision in Mice.

Visual impairments, notably loss of contrast sensitivity and color vision, were documented in Alzheimer's disease (AD) patients yet are critically understudied. This protocol describes a novel visual-stimuli four-arm maze (ViS4M; also called visual x-maze), which is a versatile x-shaped maze equipped with spectrum- and intensity-controlled light-emitting diode (LED) sources and dynamic grayscale objects. The ViS4M is designed to allow the assessment of color and contrast vision along with locomotor and cognitive functions in mice. In the color testing mode, the spectral distributions of the LED lights create four homogenous spaces that differ in chromaticity and luminance, corresponding to the mouse visual system. In the contrast sensitivity test, the four grayscale objects are placed in the middle of each arm, contrasting against the black walls and the white floors of the maze. Upon entering the maze, healthy wild-type (WT) mice tend to spontaneously alternate between arms, even under equiluminant conditions of illumination, suggesting that cognitively and visually intact mice use both color and brightness as cues to navigate the maze. Evaluation of the double-transgenic APPSWE/PS1ΔE9 mouse model of AD (AD+ mice) reveals substantial deficits to alternate in both color and contrast modes at an early age, when hippocampal-based memory and learning is still intact. Profiling of timespan, entries, and transition patterns between the different arms uncovers variable aging and AD-associated impairments in color discrimination and contrast sensitivity. The analysis of arm sequences of alternation reveals different pathways of exploration in young WT, old WT, and AD+ mice, which can be used as color and contrast imprints of functionally intact versus impaired mice. Overall, we describe the utility of a novel visual x-maze test to identify behavioral changes in mice related to cognition, as well as color and contrast vision, with high precision and reproducibility. Graphic abstract: Exploratory behavior of AD+ mice versus age- and sex-matched WT mice is tracked (top left: trajectory from a 5-min video file) in a novel visual-stimuli four-arm maze (ViS4M; also named visual x-maze) equipped with spectrum- and intensity-controlled LED sources or grayscale objects. Consecutive arm entries reveal that APPSWE/PS1ΔE9 (AD+) mice alternate less between arms, as opposed to WT mice. Sequence analysis, according to the three alternation pathways (depicted by white, yellow, and brown arrows) under different conditions of illumination, uncovers specific deficits linked to color vision in AD+ mice, evidenced by a color imprint chart.

Practical Color Contrast Sensitivity Functions for Luminance Levels up to 10000 cd/m<sup>2</sup>

We model color contrast sensitivity for Gabor patches as a function of spatial frequency, luminance and chromacity of the background, modulation direction in the color space and stimulus size. To fit the model parameters, we combine the data from five independent datasets, which let us make predictions for background luminance levels between 0.0002 cd/m2 and 10 000 cd/m2, and for spatial frequencies between 0.06 cpd and 32 cpd. The data are well-explained by two models: a model that encodes cone contrast and a model that encodes postreceptoral, opponent-color contrast. Our intention is to create practical models, which can well explain the detection performance for natural viewing in a wide range of conditions. As our models are fitted to the data spanning very large range of luminance, they can find applications in modeling visual performance for high dynamic range and augmented reality displays.

Image quality evaluation for high dynamic range and wide color gamut applications using visual spatial processing of color differences

AbstractHigh dynamic range (HDR) and wide color gamut imagery has an established video ecosystem, spanning image capture to encoding and display. This drives the need for evaluating how image quality is affected by the multitudes of ecosystem parameters. The simplest quality metrics evaluate color differences on a pixel‐by‐pixel basis. In this article, we evaluate a series of these color difference metrics on four HDR and three standard dynamic range publicly available distortion databases consisting of natural images and subjective scores. We compare the performance of the well‐established CIE L*a*b* metrics (ΔE00, ΔE94) alongside two HDR‐specific metrics (ΔEZ [Jzazbz], ΔEITP [ICTCP]) and a spatial CIE L*a*b* extension (). We also present a novel spatial extension to ΔEITP derived by optimizing the opponent color contrast sensitivity functions. We observe that this advanced metric, , outperforms the other color difference metrics, and we quantify the improved performance with the steps of metric advancement.

Functional retinal outcomes in patients with prediabetes and type 2 diabetes.

Type 2 diabetes (T2DM) is a leading cause of visual impairment. Its precursor, prediabetes (preDM), is growing in numbers every year. While it is well known that T2DM causes changes in retinal function early in the disease process, it is likely that some of these changes emerge during the preDM stage. This study evaluates retinal function measures in patients with preDM to determine if there are differences in colour vision, contrast sensitivity (CS), and multifocal electroretinogram (mfERG) measures present before T2DM is diagnosed. The L'Anthony desaturated D-15 test, Mars Chart CS test, and mfERG were administered on the right eye of 43 participants; 15 controls (HbA1c 5.6%), 17 with preDM (HbA1c 5.7%-6.4%), and 11 with T2DM (either physician diagnosed or with untreated HbA1c≥6.5%). HbA1c values were measured at the time of the other tests. Colour vision confusion scores (CVCS) were calculated from the D-15 using the method developed by Torok. Multivariate regression (which controlled for age differences) was used to evaluate the relationship of HbA1c and functional measures. Kruskal-Wallis tests were also used to evaluate differences between groups with post-hoc analysis. CVCSs were significantly different between the three groups (p=0.009). There was an association between higher CVCS and higher HbA1c values across all groups as well as specifically within the preDM group when controlling for age (R2 =0.29, p=0.01 and R2 =0.39, p=0.02 respectively). Multivariate regression of all of the functional tests together and HbA1c found only colour vision remained significant, indicating that the functional examination metrics may provide redundant data, with similar changes in prediabetes where colour vision may be the strongest indicator early in the process. Patients with prediabetes have functional changes that can be measured in the retina before the diagnosis of diabetes, with the L'Anthony D-15 colour vision test providing the strongest association with glucose dysregulation in this population. This has important implications for follow up and screening for diabetes within optometric practices. Further studies are needed to follow these patients over time to see how and when these metrics change.

HUBUNGAN LAMA PAPARAN INHALASI ORGANICSOLVENT TERHADAP PENURUNAN PENGLIHATAN WARNA DAN SENSITIVITAS KONTRAS

<p><em>Chronic inhalation of organic solvents causes retinal toxicity such as decreased color vision and contrast sensitivity because organic solvents cause damage to photoreceptor function, changes in cortical or retinal neurotransmitter systems such as glutamate, dopamine and acetylcholine and changes in function in parvo, magno and coniocellular cells.</em><em> </em><strong><em>Method</em></strong><em>: The sample of this study consisted of 45 gas station operators who were divided into 3 groups, namely those who worked 1 year</em><em>-</em><em>5 years, 5 years</em><em>-</em><em>10 years and </em><em>></em><em>10 years. All subjects underwent </em><em>q</em><em>uantitative color vision examination by calculating the value of the color confusion index (CCI) using Fansworth D15. Contrast sensitivity examination is by determining the log contrast sensitivity value using the Pelli-Robson test.</em><em> </em><strong><em>Results</em></strong><em>: CCI values> 1.00 and log contrast sensitivity values <1.65 were found in officers who worked for </em><em>></em><em>10 years by 12 subjects (80%). Statistically there is a significant relationship between the duration of work with the decrease in color vision and contrast sensitivity (P Value 0,000).</em><em> </em><strong><em>Conclusion</em></strong><em>: There is a significant relationship between the duration of exposure to organic solvents with a decrease in color vision and contrast sensitivity in operator officers who work </em><em>></em><em>10 years.</em></p>

Optically Improved Mitochondrial Function Redeems Aged Human Visual Decline.

The age spectrum of human populations is shifting toward the older with larger proportions suffering physical decline. Mitochondria influence the pace of aging as the energy they provide for cellular function in the form of adenosine triphosphate (ATP) declines with age. Mitochondrial density is greatest in photoreceptors, particularly cones that have high energy demands and mediate color vision. Hence, the retina ages faster than other organs, with a 70% ATP reduction over life and a significant decline in photoreceptor function. Mitochondria have specific light absorbance characteristics influencing their performance. Longer wavelengths spanning 650->1,000 nm improve mitochondrial complex activity, membrane potential, and ATP production. Here, we use 670-nm light to improve photoreceptor performance and measure this psychophysically in those aged 28-72 years. Rod and cone performance declined significantly after approximately 40 years of age. 670-nm light had no impact in younger individuals, but in those around 40 years and older, significant improvements were obtained in color contrast sensitivity for the blue visual axis (tritan) known to display mitochondrial vulnerability. The red visual axis (protan) improved but not significantly. Rod thresholds also improved significantly in those >40 years. Using specific wavelengths to enhance mitochondrial performance will be significant in moderating the aging process in this metabolically demanding tissue.

Use of the King-Devick Variable Color Contrast Sensitivity Chart to differentiate stages of age-related macular degeneration

ObjectiveThis study aimed to determine which colour contrast sensitivity differences exist in early to advanced age-related macular degeneration (AMD) and examine the potential utility of the King-Devick Variable Color Contrast...

Relationship between refractive correction, visual symptoms, and optical device selection for low-vision patients in Taiwan

According to Taiwan optometry act, low-vision services, such as refractive correction and low vision assessment, are now included in Optometric profession. This study was designed to investigate the efficiency of refractive correction and the relationship between refractive correction, eye diseases, visual symptoms, and optical device selection for patients with low vision. MethodsThis study involved a total of 220 participants aged from 7 to 99, with 119 males and 101 females. All of them were referred from three institutes of Taiwan Resource Portal of Assistive Technology under the supervision of the Ministry of Health and Welfare during Feb 2016 to Jan 2018. Accordingly, 42, 76, and 102 of the participants were identified as having mild, moderate, and severe visual impairments, respectively, by five experienced and licensed optometrists for this comprehensive low vision examination. ResultsThe most common eye diseases in this study were retinal disease, cataract, glaucoma, and optic nerve hypoplasia; some of the participants had multiple eye diseases while participating in the study. Except visual acuity decrease, eye diseases were highly correlated with participants’ visual symptoms. Refractive correction is the first step in low-vision examination, therefore, it might be much helpful to some types of eye diseases, visual symptoms, and to the decisions of optical devices for low-vision patients. The results herein suggest that color vision and contrast sensitivity should be taken into consideration when calculating the second optical magnifying power after refractive correction. ConclusionsRefractive correction is necessary for the treatment of patients’ visual symptoms and also for the prescription of low-vision aids.

Neuropathie optique dans le syndrome des anticorps anti MOG positif

The diagnosis of optic neuritis (ON), or inflammation of the optic nerve, is based on clinical findings: first marked by rapidly progressive visual decline associated with eye pain accentuated by eye movements; abnormalities of color perception and/or contrast sensitivity may also be reported. In this case, inflammatory neuropathies are associated with anti-MOG antibodies. MOGs, oligodendrocytic glycoproteins involved in the production of myelin, were identified nearly three decades ago in association with demyelinating ON. The first series were reported in children following demyelinating neurological manifestations, particularly in ADEM (acute demyelinating encephalomyelitis) or multiple sclerosis (MS) [1]. Anti-MOGs are associated with neuropathies in the phenotypic setting of the neuromyelitis optica (NO) spectrum, and anti-Aquaporin 4antibodies (AQP4) are negative by definition. Thus, anti-MOG could explain up to 30% of cases of seronegative optic neuritis; their presence thus represents a significant diagnostic aid for the clinician, especially during a first neurological episode [1]. The first short published series in AQP4-/MOG+populations revealed primarily ophthalmological involvement with a good prognosis for recovery [1]. Knowledge of these antigens is important; it may permit not only an understanding of the physiopathology but also the stratification of patients in terms of prognosis and response to treatment [2]. Thus, the early diagnosis of anti-MOG positive ON must prompt aggressive initial treatment and a more or less maintenance therapy to prevent recurrence. The role of the ophthalmologist remains paramount, since most cases present with purely ocular involvement. We report herein the clinical, ophthalmological, laboratory and radiological data for 25patients (45eyes) managed between February 2011and January 2017. All of our patients had optic neuritis associated with anti-MOG antibodies. All patients underwent the following testing: -Visual acuity; -Humphrey and/or Goldmann visual field; -Non-mydriatic fundus photography; -Optic disc OCT; -3Tesla orbital-cerebral MRI with and without contrast; -Standard and immunological laboratory testing for anti-MOG and anti AQP4antibodies by Western Blot and ELISA. The male: female ratio of the population was 0.92 (13women and 12men). The average age at onset was 35.68years (15to 60years); 40% of the subjects were between 31and 40years old. The initial symptoms leading to consultation were mostly visual acuity (80%) and pain (88%). Involvement was bilateral in 80% of cases (5unilateral). Initial visual acuity was poor; 52% of eyes were less than or equal to count fingers. The course was favorable however, with visual acuity returning to 10-12/10after 6months of follow-up (84% of eyes). Orbital/cerebral MRI with attention to the visual pathways revealed involvement of the anterior visual pathways with gadolinium uptake in 92% of cases. Of the 35eyes initially considered affected, the main initial diagnoses were: -36% retro-bulbar optic neuritis (RBON); -40% anterior optic neuritis (AON); -24% other; of which 16% were initially diagnosed as acute anterior ischemic optic neuropathy (AAION). 96% of patients received corticosteroid treatment in the acute phase. 16% required plasma exchange sessions. Maintenance therapy was proposed for only 36% of the population. Optic neuritis is a pathology frequently encountered in ophthalmology; a good knowledge of symptoms and clinical signs is essential for early diagnosis and optimal management. The identification of autoantibodies, including anti-MOG antibodies, is important for patient management and is part of the required testing for all cases of optic neuritis, in order to adapt the treatment of the acute episode and to provide maintenance therapy to avoid recurrence.

Colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration.

Purpose:To generate the first published reference database of colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration and to explore this important feature in quality of vision.Background:Quality of vision depends on many factors. Changes in chromatic contrast sensitivity remain largely unexplored in eyes at high risk of neovascular age-related macular degeneration; they may however not only be relevant for quality of life but also an early indicator of the onset of the disease, so it is important to have a means to evaluate any variation in colour contrast sensitivity, especially in view of the likely increase in neovascular age-related macular degeneration as the population ages.Methods:This prospective longitudinal study evaluated colour contrast sensitivity along the protan and tritan colour axes in 145 eyes at high risk of neovascular age-related macular degeneration.Results:Colour contrast sensitivity showed statistically significant correlations with age and visual acuity, but not gender nor laterality (i.e. whether the right or left eye was being tested). There was significant variability among individuals, especially for the tritan axis, with some subjects well within normal limits for age and others with very poor colour contrast sensitivity.Conclusion:This study has generated the first published colour contrast sensitivity reference database for eyes at high risk of neovascular age-related macular degeneration. It has also shown a high inter-individual variability of colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration, but the significance of this is unclear. Further work is required to establish if eyes with high colour contrast sensitivity thresholds (i.e. poor colour vision) have a higher risk of developing neovascular age-related macular degeneration over time, and this is the subject of ongoing work.

Evaluation of color vision and contrast sensitivity in diabetic patients without retinopathy

Evaluation of color vision and contrast sensitivity in diabetic patients without retinopathy

Study of Visual Function in Adult Epileptic Patients on Sodium Valproate or Carbamazepine Monotherapy.

ObjectiveEpilepsy is a debilitating disease. Visual function changes have been reported and may be attributed to the epileptic changes or as a result of medication side effect. Sodium valproate and carbamazepine are both first line anti-epileptic medications used in Malaysian health care. Sodium valproate inhibits glutamate and γ-aminobutyric acid (GABA) transaminase while carbamazepine acts on the sodium channel - both are an important part of the retina. This study aimed to compare the visual functions of epilepsy patients on carbamazepine or sodium valproate monotherapy.DesignA cross-sectional study was conducted at a tertiary hospital between June 2016 and November 2018.MethodsPatients with idiopathic epilepsy that fulfill the inclusion and exclusion criteria were recruited from the neurology clinic. They were divided into two groups and underwent complete eye examinations. Visual functions such as color vision testing, contrast sensitivity, visual field and retinal nerve fiber layer measurement were subsequently performed. Statistical analysis was done using Statistical Package for the Social Science, version 24 (SPSS Inc, Chicago, IL, USA).ResultsA total of 100 patients (sodium valproate: 50 patients; carbamazepine: 50 patients) were recruited for the study. There were no statistically significant changes in anatomical or visual function between the sodium valproate and carbamazepine group. However, patients from both groups displayed color vision defect in the blue and green axes. Changes in color vision could indicate early retina toxicity secondary to the medication. Although there were no visual field changes, patients recorded a slight reduction of mean deviation. Changes of mean deviation could be attributed to the side effect of medication or the disease process.ConclusionsEpileptic patients taking sodium valproate or carbamazepine did not demonstrate statistically significant change in visual function.

LRRK2-associated Parkinson's disease patients have better stereopsis than idiopathic Parkinson disease

ObjectivesVisual dysfunctions are frequent and have several manifestations in idiopathic Parkinson's disease (PD). However, the characteristics of these complications in LRRK2 (leucine-rich kinase 2)-associated PD patients still lack systematic research. The purpose of this study is to assess visual functions of LRRK2-associated PD patients. Patients and methodsTwenty-five (25) PD patients with LRRK2 R1628P and G2385R variants were included in the study and compared to 28 PD patients without these variants and 28 age-matched healthy controls. The genotypes of PD patients were kept double-blinded. Information on age, sex, disease duration, the movement disorder society-unified Parkinson's disease rating scale (MDS-UPDRS), Hoehn and Yahr staging scale (H&Y), Mini-Mental Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were included. Visual functions assessment included color perception, contrast sensitivity and stereopsis. ResultsPD patients with or without LRRK2 R1628P and G2385R variants have declined contrast sensitivity, diminished color discrimination and damaged stereopsis. There was no significant difference in retinal level visual deficiency (color discrimination and contrast sensitivity) between PD with LRRK2 variants and those without, but cortex level visual function, i.e. stereopsis is better in PD with LRRK2 variants than non-carrier PD patients. The associated factors of stereopsis are different. The stereopsis is associated with MoCA scores independently in non-carrier PD patients, but with UPDRSIII scores in LRRK2-associated PD patients. ConclusionsVisual functions are similarly affected in PD patients with and without LRRK2 R1628P and G2385R variants, but LRRK2-associated PD patients have better stereopsis than idiopathic PD patients.