Early life stress induces visual dysfunction and retinal structural alterations in adult mice.

Early life stress (ELS) is defined as a period of severe and/or chronic trauma, as well as environmental/social deprivation or neglect in the prenatal/early postnatal stage. Presently, the impact of ELS on the retina in the adult stage is unknown. The long-term consequences of ELS at retinal level were analyzed in an animal model of maternal separation with early weaning (MSEW), which mimics early life maternal neglect. For this purpose, mice were separated from the dams for 2 h at postnatal days (PNDs) 4-6, for 3 h at PNDs 7-9, for 4 h at PNDs 10-12, for 6 h at PNDs 13-16, and weaned at PND17. At the end of each separation period, mothers were subjected to movement restriction for 10 min. Control pups were left undisturbed from PND0, and weaned at PND21. Electroretinograms, visual evoked potentials, vision-guided behavioral tests, retinal anterograde transport, and retinal histopathology were examined at PNDs 60-80. MSEW induced long-lasting functional and histological effects at retinal level, including decreased retinal ganglion cell function and alterations in vision-guided behaviors, likely associated to decreased synaptophysin content, retina-superior colliculus communication deficit, increased microglial phagocytic activity, and retinal ganglion cell loss through a corticoid-dependent mechanism. A treatment with mifepristone, injected every 3 days between PNDs 4 and16, prevented functional and structural alterations induced by MSEW. These results suggest that retinal alterations might be included among the childhood adversity-induced threats to life quality, and that an early intervention with mifepristone avoided ELS-induced retinal disturbances.

Magnetization transfer saturation reveals subclinical optic nerve injury in pediatric-onset multiple sclerosis.

BACKGROUND: The presence of subclinical optic nerve (ON) injury in youth living with pediatric-onset MS has not been fully elucidated. Magnetization transfer saturation (MTsat) is an advanced magnetic resonance imaging (MRI) parameter sensitive to myelin density and microstructural integrity, which can be applied to the study of the ON. OBJECTIVE: The objective of this study was to investigate the presence of subclinical ON abnormalities in pediatric-onset MS by means of magnetization transfer saturation and evaluate their association with other structural and functional parameters of visual pathway integrity. METHODS: Eleven youth living with pediatric-onset MS (ylPOMS) and no previous history of optic neuritis and 18 controls underwent standardized brain MRI, optical coherence tomography (OCT), Magnetoencephalography (MEG)-Visual Evoked Potentials (VEPs), and visual battery. Data were analyzed with mixed effect models. RESULTS: While ON volume, OCT parameters, occipital MEG-VEPs outcomes, and visual function did not differ significantly between ylPOMS and controls, ylPOMS had lower MTsat in the supratentorial normal appearing white matter (-0.26 nU, p = 0.0023), and in both in the ON (-0.62 nU, p < 0.001) and in the normal appearing white matter of the optic radiation (-0.56 nU, p = 0.00071), with these being positively correlated (+0.57 nU, p = 0.00037). CONCLUSIONS: Subclinical microstructural injury affects the ON of ylPOMS. This may appear as MTsat changes before being detectable by other currently available testing.

Three Major Causes of Metabolic Retinal Degenerations and Three Ways to Avoid Them.

An imbalance of homeostasis in the retina leads to neuron loss and this eventually results in a deterioration of vision. If the stress threshold is exceeded, different protective/survival mechanisms are activated. Numerous key molecular actors contribute to prevalent metabolically induced retinal diseases-the three major challenges are age-related alterations, diabetic retinopathy and glaucoma. These diseases have complex dysregulation of glucose-, lipid-, amino acid or purine metabolism. In this review, we summarize current knowledge on possible ways of preventing or circumventing retinal degeneration by available methods. We intend to provide a unified background, common prevention and treatment rationale for these disorders and identify the mechanisms through which these actions protect the retina. We suggest a role for herbal medicines, internal neuroprotective substances and synthetic drugs targeting four processes: parainflammation and/or glial cell activation, ischemia and related reactive oxygen species and vascular endothelial growth factor accumulation, apoptosis and/or autophagy of nerve cells and an elevation of ocular perfusion pressure and/or intraocular pressure. We conclude that in order to achieve substantial preventive or therapeutic effects, at least two of the mentioned pathways should be targeted synergistically. A repositioning of some drugs is considered to use them for the cure of the other related conditions.

How I do it: optic canal unroofing in surgery for tuberculum sellae meningiomas with compression of the optic nerve.

BACKGROUND: Tuberculum sellae meningiomas are challenging to treat when accompanied with altered vision due to compression of the optic nerve. These tumors mostly refer to be benign; therefore, gross total removal and excellent functional recovery are desired. METHOD: We describe the microsurgical treatment of tuberculum sellae meningioma with altered vision function on the left eye. Intradural unroofing of the optic canal with gross total resection of the tumor led to immediate excellent recovery. Intraoperative video highlights key steps of our surgical approach. CONCLUSION: Optic canal unroofing is in our opinion safe and mandatory when treating tuberculum sellae meningiomas with compression of optic nerve.

Visual functional defects in patients with type 2 diabetes mellitus: a questionnaire based cross-sectional study.

PURPOSE: To determine the impact of type 2 diabetes mellitus (T2DM) on visual functions, identify different modifiers as risk or protective factors, and find out how these factors affect patients' visual symptoms and visual functions as a whole. METHODS: We performed an online survey among 1030 participants (400 patients, 630 non-patients). Demographic features and severity of disease were documented, while visual functions were evaluated using National Eye Institute Visual Functioning questionnaire-25 (NEI VFQ-25). Independent t-test, analysis of variance, linear and nonlinear regression models were used to assess all data. RESULTS: Scores other than color vision among T2DM patients were significantly lower compared with non-T2DM participants. There was significant difference after stratification of age and education, but no significant difference between different genders was observed. Parameters including duration of T2DM, fasting plasma glucose (FPG) and glycosylated hemoglobin A1c (HbA1c) negatively impacted on the scores, with 20 years' of diabetic duration, 10 mmol/L of FPG, 7.5% of HbA1c being potential cut-off points. Poorer best corrected visual acuity (BCVA) and diagnosis of diabetic retinopathy were risk factors, while they simultaneously produced mediation effect, contributing 5%-78% of effect in the deterioration of visual functions caused by longer diabetic duration and higher blood glucose. CONCLUSION: Significant visual impairments and faster deterioration in visual functions were seen in T2DM patients, with older age, lower educational level, longer diabetic duration, poorer blood glucose administration, limited BCVA, and the presence of diabetic retinopathy identified as risk factors. Average BCVA and diabetic retinopathy also yielded mediation effect as diabetic duration lengthened and blood glucose elevated.

[Results of radiation therapy for optic nerve sheath meningioma]. / Rezul'taty luchevogo lecheniya meningiomy obolochki zritel'nogo nerva.

Optic nerve sheath meningioma (ONSM) is a slow-growing benign tumor that tends to extend intracranially. The tumor is characterized by vision disturbance, optic nerve atrophy and edema. At present, radiotherapy is recommended as the treatment of choice for ONSM. PURPOSE: To assess the neuro-ophthalmic symptomatology of ONSM and how it changes in response to radiotherapy. MATERIAL AND METHODS: In the period from 2004 to 2018, 112 patients with ONSM aged 17 to 76 years underwent stereotactic radiotherapy. In 91 patients, visual functions varied from light perception to 1.0; in 21 patients the affected eye was blind. The prospective follow-up of 103 patients lasted 6 months to 10 years (mean follow-up duration was 57 months). Studied patients underwent either conventional fractionated radiotherapy with Novalis (n=88) or hypofractionation radiotherapy with CyberKnife (n=24). RESULTS: According to ophthalmological examination, in 60.5% of cases an improvement of visual functions was observed, 39.5% of patients had visual functions remain stable at the initial level. No vision impairment during irradiation was detected. Vision deterioration in the long-term follow-up was observed in 2 patients: extended tumor growth in one case and radio-induced retinopathy in the other. CONCLUSION: The study showed that this method of treatment for ONSM is effective and safe, allowing preservation of visual functions and in some cases - its improvement, while tumor growth remains under control.

The development of vision between nature and nurture: clinical implications from visual neuroscience.

BACKGROUND: Vision is an adaptive function and should be considered a prerequisite for neurodevelopment because it permits the organization and the comprehension of the sensory data collected by the visual system during daily life. For this reason, the influence of visual functions on neuromotor, cognitive, and emotional development has been investigated by several studies that have highlighted how visual functions can drive the organization and maturation of human behavior. Recent studies on animals and human models have indicated that visual functions mature gradually during post-natal life, and its development is closely linked to environment and experience. DISCUSSION: The role of vision in early brain development and some of the neuroplasticity mechanisms that have been described in the presence of cerebral damage during childhood are analyzed in this review, according to a neurorehabilitation prospective.

[Results of long-term observation of extremely premature babies with retinopathy]. / Rezul'taty dlitel'nogo nablyudeniya gluboko nedonoshennykh detei s retinopatiei.

PURPOSE: To study the long-term clinical and functional outcomes of retinopathy in extremely premature infants. MATERIAL AND METHODS: The study included 42 patients (84 eyes) with retinopathy of prematurity (ROP) at the age of 9-18 years. All patients underwent comprehensive ophthalmological examination, including morphometric (OCT), functional (ERG) and psycho-physical (computer perimetry) methods. RESULTS: A high occurrence of low vision (67%) was revealed in extremely premature children with ROP during school years and adolescence, which depended on the severity of active ROP and the formation of pronounced residual changes in the fundus during the cicatricial phase of the disease, a high occurrence of refractive errors (92%), including high degree myopia (46%), late complications that develop with ROP of any degree (68%), impaired retinal electrogenesis - due to both ROP and deep morphological and functional immaturity of the retina. CONCLUSION: Patients with any degree of cicatricial ROP born in the early stages of gestation and with extremely low body weight need regular complex ophthalmologic examination and lifelong follow-up.

[Practical application of ophthalmic nutraceuticals in patients with dry form of age-related macular degeneration]. / Primenenie oftal'monutritsevtika pri «sukhoi¼ forme vozrastnoi makulyarnoi degeneratsii.

Development and progression of age-related macular degeneration (AMD) is associated with insufficiency of protective antioxidant systems of the body. Nutraceutical medications can positively affect the course of the disease and the visual functions of patients with AMD. PURPOSE: To conduct a placebo-controlled clinical monitoring of visual functions in patients with dry AMD while taking a drug Complex that corresponds to the AREDS 2 formula. MATERIAL AND METHODS: The study included 90 people in 3 equivalent parallel groups, two of which were represented by patients with AMD who took the Complex for 3-6 months or Placebo for 3 months. The third group included healthy subjects of the same age. In addition to standard eye examination, participants underwent evaluation of the macular pigment optical density (MPOD), spatial-frequency contrast sensitivity (CS), photostress test, and reading parameters on the Salzburg Reading Desk device. The changes of blood plasma antioxidant activity (AOA) were also evaluated in the main group. RESULTS: By day 90 of the study, patients of the main group showed statistically significant (p<0.001) growth of MPOD from 0.24±0.13 to 0.32±0.1, reduction of photostress recovery time from 68.2±17.8 to 57.3±17.5 seconds, improvement of high-spatial-frequency CS - from 25.0±8.2 to 30.6±6.8 dB, increase of near visual acuity logMAR from 0.22±0.04 to 0.19±0.03 and reading speed, and decrease of reading mistakes. Statistically significant (p<0.05) reduction of in AOA was seen during the observation period from 1.52±0.16 to 1.68±0.16. Patients of the main group who received the Complex for 180 days demonstrated additional improvements of visual functions. CONCLUSION: The drug Complex corresponding to the AREDS 2 formula contributes to a significant increase in MPOD, improvements of visual functions and overall antioxidant status of patients, which confirms the feasibility of its use in patients with dry AMD.

Effects of subtenon-injected autologous platelet-rich plasma on visual functions in eyes with retinitis pigmentosa: preliminary clinical results.

PURPOSE: One of the main reasons for apoptosis and dormant cell phases in degenerative retinal diseases such as retinitis pigmentosa (RP) is growth factor withdrawal in the cellular microenvironment. Growth factors and neurotrophins can significantly slow down retinal degeneration and cell death in animal models. One possible source of autologous growth factors is platelet-rich plasma. The purpose of this study was to determine if subtenon injections of autologous platelet-rich plasma (aPRP) can have beneficial effects on visual function in RP patients by reactivating dormant photoreceptors. MATERIAL AND METHODS: This prospective open-label clinical trial, conducted between September 2016 and February 2017, involved 71 eyes belonging to 48 RP patients with various degrees of narrowed visual field. Forty-nine eyes belonging to 37 patients were injected with aPRP. A comparison group was made up of 11 patients who had symmetrical bilateral narrowed visual field (VF) of both eyes. Among these 11 patients, one eye was injected with aPRP, while the other eye was injected with autologous platelet-poor plasma (aPPP) to serve as a control. The total duration of the study was 9 weeks: the aPRP or aPPP subtenon injections were applied three times, with 3-week intervals between injections, and the patients were followed for three more weeks after the third injection. Visual acuity (VA) tests were conducted on all patients, and VF, microperimetry (MP), and multifocal electroretinography (mfERG) tests were conducted on suitable patients to evaluate the visual function changes before and after the aPRP or aPPP injections. RESULTS: The best-corrected visual acuity values in the ETDRS chart improved by 11.6 letters (from 70 to 81.6 letters) in 19 of 48 eyes following aPRP application; this result, however, was not statistically significant (p = 0.056). Following aPRP injections in 48 eyes, the mean deviation of the VF values improved from - 25.3 to - 23.1 dB (p = 0.0001). Results regarding the mfERG P1 amplitudes improved in ring 1 from 24.4 to 38.5 nv/deg2 (p = 0.0001), in ring 2 from 6.7 to 9.3 nv/deg2 (p = 0.0301), and in ring 3 from 3.5 to 4.5 nv/deg2 (p = 0.0329). The mfERG P1 implicit times improved in ring 1 from 40.0 to 34.4 ms (p = 0.01), in ring 2 from 42.5 to 33.2 ms (p = 0.01), and in ring 3 from 42.1 to 37.9 ms (p = 0.04). The mfERG N1 amplitudes improved in ring 1 from 0.18 to 0.25 nv/deg2 (p = 0.011) and in ring 2 from 0.05 to 0.08 nv/deg2 (p = 0.014). The mfERG N1 implicit time also improved in ring 1 from 18.9 to 16.2 ms (p = 0.040) and in ring 2 from 20.9 to 15.5 ms (p = 0.002). No improvement was seen in the 11 control eyes into which aPPP was injected. In the 23 RP patients with macular involvement, the MP average threshold values improved with aPRP injections from 15.0 to 16.4 dB (p = 0.0001). No ocular or systemic adverse events related to the injections or aPRP were observed during the follow-up period. CONCLUSION: Preliminary clinical results are encouraging in terms of statistically significant improvements in VF, mfERG values, and MP. The subtenon injection of aPRP seems to be a therapeutic option for treatment and might lead to positive results in the vision of RP patients. Long-term results regarding adverse events are unknown. There have not been any serious adverse events and any ophthalmic or systemic side effects for 1 year follow-up. Further studies with long-term follow-up are needed to determine the duration of efficacy and the frequency of application.

Evaluation of tablet computers for visual function assessment.

Recent advances in technology and the increased use of tablet computers for mobile health applications such as vision testing necessitate an understanding of the behavior of the displays of such devices, to facilitate the reproduction of existing or the development of new vision assessment tests. The purpose of this study was to investigate the physical characteristics of one model of tablet computer (iPad mini Retina display) with regard to display consistency across a set of devices (15) and their potential application as clinical vision assessment tools. Once the tablet computer was switched on, it required about 13 min to reach luminance stability, while chromaticity remained constant. The luminance output of the device remained stable until a battery level of 5%. Luminance varied from center to peripheral locations of the display and with viewing angle, whereas the chromaticity did not vary. A minimal (1%) variation in luminance was observed due to temperature, and once again chromaticity remained constant. Also, these devices showed good temporal stability of luminance and chromaticity. All 15 tablet computers showed gamma functions approximating the standard gamma (2.20) and showed similar color gamut sizes, except for the blue primary, which displayed minimal variations. The physical characteristics across the 15 devices were similar and are known, thereby facilitating the use of this model of tablet computer as visual stimulus displays.

Refractive error and abnormal stereopsis association with road traffic accidents in Saudi Arabian truck drivers.

PURPOSE: To investigate the visual functions of truck drivers of the Kingdom of Saudi Arabia (KSA) in the region of Qassim and Dammam and to see if is there any association between these visual functions and self-reported road traffic accidents (RTA). METHODS: It is a cross-sectional, descriptive study. LogMAR visual acuity, refractive error, color vision, stereopsis, and confrontation visual fields were measured in 300 truck drivers in the Qassim and Dammam regions of KSA. Driving-related history and incidence of RTA from the past 3 years, systemic history, and general eye compliance history were collected through a self-reporting questionnaire. RESULTS: Among 300 truck drivers examined, 54 (18.4%) subjects have a refractive error, 14 (4.7%) subjects have color vision deficiency, 37 (12.2%) subjects have abnormal stereo acuity, and none of them have confrontation visual field defect. RTA was reported in 25 (8.3%) subjects. The current study has found RTA is significantly associated with refractive error (P = 0.01) and abnormal stereopsis (P < 0.01). Systemic history revealed that 11% of the subjects had diabetes mellitus. CONCLUSION: The current study is the first to report on the visual functions of KSA truck drivers. Hence, the current study has found a significant association between visual functions and RTA among truck drivers, we recommend a comprehensive examination need to be part of issuing driver's licenses in KSA. More studies with larger samples from different regions of KSA are needed to extrapolate these findings.

Visual Function and Driving Performance Under Different Lighting Conditions in Older Drivers: Preliminary Results From an Observational Study.

BACKGROUND: Age-related vision changes significantly contribute to fatal crashes at night among older drivers. However, the effects of lighting conditions on age-related vision changes and associated driving performance remain unclear. OBJECTIVE: This pilot study examined the associations between visual function and driving performance assessed by a high-fidelity driving simulator among drivers 60 and older across 3 lighting conditions: daytime (photopic), nighttime (mesopic), and nighttime with glare. METHODS: Active drivers aged 60 years or older participated in visual function assessments and simulated driving on a high-fidelity driving simulator. Visual acuity (VA), contrast sensitivity function (CSF), and visual field map (VFM) were measured using quantitative VA, quantitative CSF, and quantitative VFM procedures under photopic and mesopic conditions. VA and CSF were also obtained in the presence of glare in the mesopic condition. Two summary metrics, the area under the log CSF (AULCSF) and volume under the surface of VFM (VUSVFM), quantified CSF and VFM. Driving performance measures (average speed, SD of speed [SDspeed], SD of lane position (SDLP), and reaction time) were assessed under daytime, nighttime, and nighttime with glare conditions. Pearson correlations determined the associations between visual function and driving performance across the 3 lighting conditions. RESULTS: Of the 20 drivers included, the average age was 70.3 years; 55% were male. Poor photopic VA was significantly correlated with greater SDspeed (r=0.26; P<.001) and greater SDLP (r=0.31; P<.001). Poor photopic AULCSF was correlated with greater SDLP (r=-0.22; P=.01). Poor mesopic VUSFVM was significantly correlated with slower average speed (r=-0.24; P=.007), larger SDspeed (r=-0.19; P=.04), greater SDLP (r=-0.22; P=.007), and longer reaction times (r=-0.22; P=.04) while driving at night. For functional vision in the mesopic condition with glare, poor VA was significantly correlated with longer reaction times (r=0.21; P=.046) while driving at night with glare; poor AULCSF was significantly correlated with slower speed (r=-0.32; P<.001), greater SDLP (r=-0.26; P=.001) and longer reaction times (r=-0.2; P=.04) while driving at night with glare. No other significant correlations were observed between visual function and driving performance under the same lighting conditions. CONCLUSIONS: Visual functions differentially affect driving performance in different lighting conditions among older drivers, with more substantial impacts on driving during nighttime, especially in glare. Additional research with larger sample sizes is needed to confirm these results.

Stability of axis and patient satisfaction after toric implantable collamer lens implantation for myopic astigmatism.

OBJECTIVES: To assess the stability of axis and patient satisfaction after toric visian implantable collamer lens (TICL) implantation for moderate to high myopic astigmatism. METHODS: Total 33 eyes of 21 consecutive patients who underwent implantation of TICL for the correction of moderate to high myopic astigmatism were recorded and a minimum follow-up of six months was performed. The deviation of axis of TICL was detected from one week to six months postoperatively. The evaluation of the visual functions was done by the same clinician at six months after surgery. RESULTS: The mean refractive cylinder decreased from -2.48±0.91 diopters (D) preoperatively to -0.54±0.25D and -0.50±0.19D at one week and six months after surgery respectively. Mean changes in astigmatism from one week to six months after surgery was 0.03±0.17D. The mean deviation of axis of TICL from one week to six months postoperatively was 2.48±1.25°(range,1°~ 6°) and no TICL required secondary repositioning. 14.3% patients felt difficult about the middle distant visual function (Reading Computer Screen). Evaluations of other visual functions were positive or very positive. Conclusions : Six months after implantation of the TICL, it showed slightly axis rotation and high satisfaction about the visual functions.

Computational analysis of retinal image quality with different contact lens designs in keratoconus.

PURPOSE: To determine 1) the relative differences in optical quality of keratoconic eyes fitted with four routinely used CL designs and 2) the Zernike coefficients in the residual wavefront aberration map that may be responsible for differences in the optical quality of keratoconic eyes fitted with these CLs. METHODS: Wavefront aberrations over a 3-mm pupil diameter were measured without and with Kerasoft IC®, Rose K2®, conventional spherical Rigid Gas Permeable (RGP), and Scleral CLs in 15 mild to moderate keratoconic eyes (20 - 28 years) and under unaided viewing in 10 age-similar non-contact lens wearing controls. The resultant through-focus curves constructed for the logarithm of Neural Sharpness (logNS) Image Quality (IQ) metric were quantified in terms of peak value, best focus, and depth of focus. Sensitivity analyses determined the impact of the residual Zernike coefficients of keratoconic eyes fitted with CLs on the IQ of controls at emmetropic refraction. RESULTS: The peak IQ and depth of focus were similar with Rose K2®, conventional RGP, and Scleral CLs (p > 0.05, for all) but significantly better than Kerasoft IC® CLs (p < 0.01 for all). Best focus was similar across all four CLs (p > 0.2 for all). However, the IQ parameters of all the lenses remained significantly poorer than the controls (p < 0.01, for all). The IQ of the controls dropped to keratoconic levels with induced residual lower-order Zernike terms and 3rd-order coma across all lenses in the sensitivity analysis (p < 0.001). CONCLUSIONS: IQ of keratoconic eyes remain suboptimal with routinely dispensed CL designs, largely due to residual lower-order aberrations and coma, all relative to the controls. The performance drop appears greater for the Kerasoft IC® CL relative to the other CL designs. These results may provide the optical basis for psychophysical spatial visual performance reported earlier across these four CL designs for keratoconus.

Innovative vision rehabilitation method for epiretinal membrane: Enhancing visual functions through Biofeedback Training.

Purpose: To report a case with epiretinal membrane (ERM) treated with audio-luminous Biofeedback training (BT) which resulted in improvement of monocular and binocular visual functions. Observations: We report a case of ERM with distance Best Corrected Visual Acuity (BCVA) of 20/40 in the right dominant eye, and 20/20 in the left eye. The main symptom was binocular blurry vision, and the patient did not desire to pursue posterior vitrectomy due to its risks. Using a 10-2 microperimetry test with the MAIA Microperimeter, it was possible to identify an inferior paracentral relative scotoma in the right eye with splitting fixation. The right eye was trained with five 20-minute sessions with Biofeedback training towards a trained retinal locus (TRL) with better retinal sensitivity and 1.46° superior and temporal to the current preferred retinal locus (PRL). After training, the patient reported total improvement of symptoms, and BCVA was 20/25 in the right eye and 20/20 in the left eye. Conclusions and importance: Biofeedback training is a valuable treatment with no known adverse effects that can be performed as an alternative to patients with ERM with no surgical indication and debilitating symptoms, or as a post-surgery adjuvant treatment.

Effect of changing mesopic and photopic light conditions on visual functions.

AIM: To determine the effects of change in light conditions on refractive error and visual functions including visual acuity, stereopsis and contrast sensitivity. METHODS: This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022. All of them had eye health and normal visual function and could have refractive errors or not. Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition. The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured. Also, visual acuity, stereopsis and contrast sensitivity (in five spatial frequencies of 1.5, 3, 6, 12, and 18 cycles per degree), were measured first in photopic light condition and then in mesopic light condition, by Snellen control vision chart, stereo butterfly test and the M&S technology monitor test respectively. RESULTS: In the 48 student subjects with an average age of 22.69±3.56y, mean of refractive error as sphere equivalent, visual acuity and stereopsis were -1.25±1.74 diopters, 0 logMAR, 44.37±13.03 seconds of arc, respectively in photopic light condition while in mesopic light was equal to -1.56±1.75 diopters, 0.12±0.09 logMAR and 50.62±33.35 seconds of arc, respectively. The mean of contrast sensitivity measured at spatial frequencies of 1.5, 3, 6, 12, and 18 cycles per degree in photopic condition was equal to 2.38±0.04, 2.37±0.07, 2.04±0.21, 1.27±0.32, 0.82±0.27 logarithm of contrast sensitivity, respectively and in mesopic lighting condition was equal to 2.34±0.12, 2.30±0.16, 1.84±0.28, 1.02±0.28, 0.63±0.24 logarithm of contrast sensitivity, respectively. Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables [refractive error (P<0.001), visual acuity (P<0.001), stereopsis (P=0.008) and contrast sensitivity (P<0.001)]. CONCLUSION: The refractive error of the student subjects in mesopic light condition change towards myopia, and its amount is clinically significant. Also, the examination and comparison of the factors of visual acuity, stereopsis and contrast sensitivity in these two lighting conditions show that the decrease in brightness level to the mesopic level causes a decrease in the aforementioned visual functions.

FunctionaL Assessment Scale of Hemianopia (FLASH): A New Multidisciplinary Tool to Assess Hemianopia in Patients with Severe Acquired Brain Injury.

BACKGROUND: Severe acquired brain injury (sABI) encompasses a range of neurological impairments. Visual dysfunction, particularly homonymous visual field defects (HVFDs) and homonymous hemianopia (HH), commonly afflicts sABI survivors, affecting their cognitive and motor rehabilitation. This study presents the FunctionaL Assessment Scale of Hemianopia (FLASH), developed to analyze the most common postural behaviors exhibited by sABI patients with hemianopia during activities of daily living. A comparison to traditional static automated perimetry for diagnosing visual field deficits (VFDs) to determine the sensitivity and specificity of the FLASH was used. Additionally, this study also aimed to assess its reliability. METHODS: Fifty-six patients (25 F, 31 M, mean age 60.59 ± 14.53) with strokes in the sub-acute phase (<6 months from the onset) were assessed with both FLASH and a Humphrey Field Analyzer. RESULTS: After removing two items found to be less reliable than others, FLASH showed high sensitivity (81%) and specificity (77%) when compared to static automated perimetry. Inter-rater reliability was also high, with an intra-class correlation coefficient of 0.954, as well as the internal consistency computed by Cronbach's alpha, equal to 0.874. CONCLUSION: FLASH could offer a valuable and cost-effective screening tool for VFD in sABI patients during neurorehabilitation, with potential implications for healthcare cost reduction.

Mid-range visual functions in relation to higher-order visual functions after stroke.

INTRODUCTION: We aimed to investigate whether associations between deficits in "mid-range" visual functions and deficits in higher-order visual cognitive functions in stroke patients are more in line with a hierarchical, two-pathway model of the visual brain, or with a patchwork model, which assumes a parallel organization with many processing routes and cross-talk. METHODS: A group of 182 ischemic stroke patients was assessed with a new diagnostic set-up for the investigation of a comprehensive range of visuosensory mid-range functions: color, shape, location, orientation, correlated motion, contrast and texture. With logistic regression analyses we investigated the predictive value of these mid-range functions for deficits in visuoconstruction (Copy of the Rey-Complex Figure Test), visual emotion recognition (Ekman 60 Faces Test of the FEEST) and visual memory (computerized Doors-test). RESULTS: Results showed that performance on most mid-range visual tasks could not predict performance on higher-order visual cognitive tasks. Correlations were low to weak. Impaired visuoconstruction and visual memory were only modestly predicted by a worse location perception. Impaired emotion perception was modestly predicted by a worse orientation perception. In addition, double dissociations were found: there were patients with selective deficits in mid-range visual functions without higher-order visual deficits and vice versa. CONCLUSIONS: Our findings are not in line with the hierarchical, two-pathway model. Instead, the findings are more in line with alternative "patchwork" models, arguing for a parallel organization with many processing routes and cross-talk. However, future studies are needed to test these alternative models.

Comparison of visual requirements and regulations for obtaining a driving license in different European countries and some open questions on their adequacy.

We reviewed the current state of knowledge regarding visual function and its suitability as part of medical examinations for driving licenses. We focused only on Group 1 drivers. According to previous studies, visual acuity, which is the most common test, is weakly associated with a higher risk of road accidents, with a greater role of visual field. The inclusion of the visual field test in medical examinations is therefore important, but the actual limit value is still unclear and further research in specific situations is needed. Color vision impairment was not found a threat to traffic safety. Contrast sensitivity decreases with age and is affected by abnormal eye conditions. Resulting glare can lead to an increased risk of traffic accidents during night driving in the elderly and others with conditions that impair contrast sensitivity. However, the universal cut-off limits have not been established either. The current European Union (EU) regulations therefore reflect minimum common denominator across the member states which may not entirely translate to optimal driving safety. Due to these open questions, standardized testing in simulators or on polygons that simulate real life conditions would be needed to better determine safe limits of visual function in different conditions. As there is a need to have better standardization across Europe regarding the requirements and rules regarding driving licenses in European countries, we first analyzed existing rules and compared them with each other, also in terms of deviations from the EU directive itself. We reviewed the literature in this field and prepared proposals for a more optimal regulation of the rules in the future. Particular attention is paid to the new method of examining the visual field that was created to respect the European directive. The paper can serve as a basis of information for research teams to design further protocols, as it gathers research findings to date on the importance and impact of various visual functions on driving safety, as well as a starting point for a debate on revising existing rules for obtaining and maintaining licenses, as it compares the current regulations in European countries and differences between them.