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Background: The timing of an event within an oscillatory phase is considered to be one of the key strategies used by the brain to code and process neural information. Whereas existing methods of studying this phenomenon are chiefly based on retrospective analysis of electroencephalography (EEG) data, we now present a method to study it prospectively. New method: We present a system that allows for the delivery of visual stimuli at a specific phase of the cortical theta oscillation by fitting a sine to raw surface EEG data to estimate and predict the phase. One noteworthy feature of the method is that it can minimize potentially confounding effects of previous trials by using only a short sequence of past data. Results: In a trial with 10 human participants we achieved a significant phase locking with an inter-trial phase coherence of 0.39. We demonstrated successful phase locking on synthetic signals with a signal-to-noise ratio of less than − 20 dB. Comparison with existing method(s): We compared the new method to an autoregressive method published in the literature and found the new method was superior in mean phase offset, circular standard deviation, and prediction latency. Conclusions: By fitting sine waves to raw EEG traces, we locked visual stimuli to arbitrary phases within the theta oscillatory cycle of healthy humans. • Real-time data processing for phase-locked visual stimulation based on human surface EEG data. • Direct raw data based method for the estimation and prediction of the instantaneous phase of EEG theta oscillations. • Computationally efficient sine fitting procedure. • Robust prediction for low Signal-to-Noise Ratio (SNR) surface EEG theta oscillations. [ABSTRACT FROM AUTHOR]

Background: Optic neuritis (ON) is the most prevalent manifestation of pediatric multiple sclerosis (MSped) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGADped) in children > 6 years. In this study, we investigated retinal atrophy patterns and diagnostic accuracy of optical coherence tomography (OCT) in differentiating between both diseases after the first ON episode. Methods: Patients were retrospectively identified in eight tertial referral centers. OCT, VEP and high/low-contrast visual acuity (HCVA/LCVA) have been investigated > 6 months after the first ON. Prevalence of pathological OCT findings was identified based on data of 144 age-matched healthy controls. Results: Thirteen MOGADped (10.7 ± 4.2 years, F:M 8:5, 21 ON eyes) and 21 MSped (14.3 ± 2.4 years, F:M 19:2, 24 ON eyes) patients were recruited. We observed a significantly more profound atrophy of both peripapillary and macular retinal nerve fiber layer in MOGADped compared to MSped (pRNFL global: 68.2 ± 16.9 vs. 89.4 ± 12.3 µm, p < 0.001; mRNFL: 0.12 ± 0.01 vs. 0.14 ± 0.01 mm3, p < 0.001). Neither other macular layers nor P100 latency differed. MOGADped developed global atrophy affecting all peripapillary segments, while MSped displayed predominantly temporal thinning. Nasal pRNFL allowed differentiation between both diseases with the highest diagnostic accuracy (AUC = 0.902, cutoff < 62.5 µm, 90.5% sensitivity and 70.8% specificity for MOGADped). OCT was also substantially more sensitive compared to VEP in identification of ON eyes in MOGAD (pathological findings in 90% vs. 14%, p = 0.016). Conclusion: First MOGAD-ON results in a more severe global peripapillary atrophy compared to predominantly temporal thinning in MS-ON. Nasal pRNFL allows differentiation between both diseases with the highest accuracy, supporting the additional diagnostic value of OCT in children with ON. [ABSTRACT FROM AUTHOR]

Background/aims The classic Goldmann applanation tonometer (GAT) has been further developed by Haag- Streit International. The applanation principle has been retained, while the internal force transmission and the pressure gauging have been optimised, the display of results digitised. The authors compared the GAT standard with the new GAT digital. Methods Four fixed tonometer pairs were used. The protocol included: non-contact pachymetry, slit-lamp examination, three consecutive measurements with each tonometer with a 5 min interval in between, check for side effects in 15 min. Three groups (intraocular pressure (IOP) levels) were defined: (1) IOP#16; (2) IOP>16 and <23; (3) IOP$23 mm Hg. Results 125 Patients (250 eyes) were evaluated. IOP (mm Hg), GAT standard versus GAT digital, for the rights eyes was: Group 1: 12.9460.55 versus 13.1160.53, p¼0.71. Group 2: 18.2660.59 versus 18.0360.52, p¼0.53; Group 3: 30.2860.48 versus 30.4260.41, p¼0.97; all right eyes: 17.4867.48 versus 17.7367.4, p¼0.99. For the left eyes, there was no significant difference, either. The correlation was very good and was not influenced by the IOP level. The Pearson coefficient for the right eye was 0.985, and for the left eye 0.994. In the BlandeAltman analysis, although there were two single readings that differed by as much as 5 mm Hg, GAT digital measures showed almost no skew, and the mean difference was 0.0361.23 mm Hg (n¼250). A multiple regression analysis showed no influence of order of measurement, eyeside or pachymetry. Conclusions The new GAT digital is as reliable and safe as GAT standard. IOP values correlate well. It offers a digitised display and a wireless transfer of data. The display of values up to the first decimal digit is not necessarily associated with a more precise measurement, but may offer an additional comfort compared with the 2 mm Hg scale of the classic GAT. [ABSTRACT FROM AUTHOR]

Abstract: Previous research has revealed that a stimulus presented in the blind visual field of participants with visual hemifield defects can evoke oculomotor competition, in the absence of awareness. Here we studied three cases to determine whether a distractor in a blind hemifield would be capable of inducing a global effect, a shift of saccade endpoint when target and distractor are close to each other, in participants with lesions of the optic radiations or striate cortex. We found that blind field distractors significantly shifted saccadic endpoints in two of three participants with lesions of either the striate cortex or distal optic radiations. The direction of the effect was paradoxical, however, in that saccadic endpoints shifted away from blind field distractors, whereas endpoints shifted towards distractors in the visible hemifields, which is the normal global effect. These results provide further evidence that elements presented in the blind visual field can generate modulatory interactions in the oculomotor system, which may differ from interactions in normal vision. [ABSTRACT FROM AUTHOR]