Effect of modulating braille dot height on reading regressions.

It is well known that people who read print or braille sometimes make eye or finger movements against the reading direction. The way these regressions are elicited has been studied in detail by manipulating linguistic aspects of the reading material. Actually, it has been shown that reducing the physical intensity or clarity of the visual input signal can also lead to increased regressions during reading.

Effects of visual search training in children with hemianopia.

Background: This study investigates the effect of a new computer-based visual search training (VST) that was adapted for children with homonymous hemianopia (HH).

Methods: 22 children with HH (median age 11 years, 8 months: 6y6m-19y2m) trained at home for 15 minutes twice/day, 5 days/week, for 6 weeks. To assess performance before training (T1), directly after training (T2) and 6 weeks after the end of training (T3), we measured search times (STs) during on-screen search (with eye tracking), and in a real life search task.

Eye Movement Training and Suggested Gaze Strategies in Tunnel Vision - A Randomized and Controlled Pilot Study.

Purpose: Degenerative retinal diseases, especially retinitis pigmentosa (RP), lead to severe peripheral visual field loss (tunnel vision), which impairs mobility. The lack of peripheral information leads to fewer horizontal eye movements and, thus, diminished scanning in RP patients in a natural environment walking task. This randomized controlled study aimed to improve mobility and the dynamic visual field by applying a compensatory Exploratory Saccadic Training (EST).

Testing macular letter recognition - reliability and influence of refraction errors.

Purpose: The goal was the validation of the Macular Mapping Test (MMT) for clinical use. We studied its susceptibility to blur caused by refractive errors and its test-retest reliability.

Methods: We tested letter recognition in 33 target locations in the central visual field (10° radius) at two contrast levels, 10 and 100 per cent.

Random word recognition chart helps scotoma assessment in low vision.

Purpose: To evaluate the use of SKread, a vision test based on random word sequences that prevents the prediction of upcoming words by linguistic criteria and is simple to score in a clinical setting.

Methods: SKread combines the standardized format of the MNread test with sequences of random words and letters like the Pepper Visual Skills for Reading test. A total of 231 subjects (aged 16 to 97 years) participated.

Parafoveal contributions to retinal function during ranibizumab therapy for age-related macular degeneration.

Objective: The standard measure for the assessment of functional vision in the central retina is best corrected visual acuity (VA). Our aim was to investigate whether it is an advantage to include tests for functional changes in the near retinal periphery to monitor treatment effects in patients receiving multiple injections of anti-vascular endothelial growth factor (anti-VEGF) agents for advanced exudative age-related macular degeneration (AMD).

Design: Prospective pilot study.

Target search and identification performance in low vision patients.

Purpose: To introduce a novel approach to topographic function assessment in visual impairment that requires neither fixation nor reading.

Methods: One hundred thirty-five consecutive low vision patients with varying diagnoses and 30 control subjects of comparable median age participated. Performance was measured in a search task that required finding and identifying visual targets which appeared consecutively on a monitor in 32 locations of the central field of gaze.

Aging and visual counting.

Background: Much previous work on how normal aging affects visual enumeration has been focused on the response time required to enumerate, with unlimited stimulus duration. There is a fundamental question, not yet addressed, of how many visual items the aging visual system can enumerate in a "single glance", without the confounding influence of eye movements.

Methodology/principal Findings: We recruited 104 observers with normal vision across the age span (age 21-85).

Parafoveal letter recognition at reduced contrast in normal aging and in patients with risk factors for AMD.

Background: Patients with early age-related maculopathy (ARM) do not necessarily show obvious morphological signs or functional impairment. Many have good visual acuity, yet complain of decreased visual performance. The aim of this study was to investigate the aging effects on performance of parafoveal letter recognition at reduced contrast, and defects caused by early ARM and normal fellow eyes of patients with unilateral age-related macular degeneration (nfAMD).

Eccentric fixation in Stargardt's disease assessed by Tübingen perimetry.

Purpose: To measure eccentric fixation characteristics in visual fields of patients with Stargardt's disease.

Methods: The positions of fixation loci (FL) in the visual field were determined by Tübingen perimetry (TP), using the position of the blind spots in 173 patients. Altogether, 669 visual fields were measured at baseline and during follow-up.

Characteristics of dynamic processing in the visual field of patients with age-related maculopathy.

Purpose: To investigate the characteristics of dynamic processing in the visual field of patients with age-related maculopathy (ARM) by measuring motion sensitivity, double-pulse resolution (DPR), and critical flicker fusion.

Methods: Fourteen subjects with ARM (18 eyes), 14 age-matched controls (19 eyes), and 7 young controls (8 eyes) served as subjects. Motion contrast thresholds were determined by a four-alternative forced-choice (4 afc) staircase procedure with a modification by Kernbach for presenting a plaid (size = 3.

Cueing attention by relative motion in the periphery of the visual field.

Sudden changes of visual stimulation attract attention. The observer's body motion generates retinal-flow field patterns containing information about his/her own speed and trajectory and relative motion of other objects. We investigated the effectiveness of relative motion as an attentional cue and compared it with conventional cueing by appearance of a frame in the far periphery of the visual field.

Quantifying fixation in patients with Stargardt disease.

Fixational eye movements in 60 eyes of 30 patients with ABCA4-associated Stargardt disease were recorded by a Scanning Laser Ophthalmoscope (SLO). The results were quantified by two new fixation quality measures expressing the eccentricity of the preferred retinal locus (PRL) non-parametrically, and fixation stability by a dynamic index. 46 eyes (77%) fixated eccentrically; in 32 eyes (70% of the eccentrically fixating eyes) the PRL was located above the central retinal lesion.

Gaze-contingent display for retinal function testing by scanning laser ophthalmoscope.

To overcome the inconvenience and imprecision of conventional software performing microperimetry with the scanning laser ophthalmoscope (SLO) in clinical settings, we developed a "smart microperimetry" program. It takes advantage of modern computer technology, especially processing speed and high rate of data transfer. It allows continuous on-line processing of the image of the retina and instantaneous correction of stimulus placement according to involuntary eye movements.

Modulation of visual stimulus discrimination by sustained focal attention: an MEG study.

Purpose: Visual attention, normally focused on the center of the visual field, can be shifted to a location in the periphery. This process facilitates the recognition of objects in the attended region. The present experiment was designed to investigate the time course of sustained attention that is known to augment stimulus perception in normal subjects.

Eye movement control during single-word reading in dyslexics.

We investigated whether dyslexics make instantaneous automatic adjustments of reading saccades depending on word length. We used a single-word reading paradigm on 10 dyslexic and 12 normally reading children aged 11-15 years. Eye movements were recorded by scanning laser ophthalmoscope (SLO) while subjects read single words of different length aloud.

Pictogram naming in dyslexic and normal children assessed by SLO.

We measured pictogram naming (PN) and text reading in dyslexic and normally reading young teenagers. Eye movements were monitored by scanning laser ophthalmoscope, revealing positions of fovea, stimuli on the retina, and speech simultaneously. While text reading speed showed the expected difference between groups, PN speeds overlapped widely.