The addition of stripes (a version of the 'horizontal-vertical illusion') increases foot clearance when crossing low-height obstacles.

Trips over obstacles are one of the main causes of falling in older adults, with vision playing an important role in successful obstacle negotiation. We determined whether a horizontal-vertical illusion, superimposed onto low-height obstacles to create a perceived increase in obstacle height, increased foot clearances during obstacle negotiation thus reducing the likelihood of tripping. Eleven adults (mean ± 1 SD: age 27.

Google Glass Glare: disability glare produced by a head-mounted visual display.

Purpose: Head mounted displays are a type of wearable technology - a market that is projected to expand rapidly over the coming years. Probably the most well known example is the device Google Glass (or 'Glass'). Here we investigate the extent to which the device display can interfere with normal visual function by producing monocular disability glare.

The newly established primary care based Welsh Low Vision Service is effective and has improved access to low vision services in Wales.

Aim: The aim of this study was to determine whether the new, primary care based, Welsh Low Vision Service (WLVS) improved access to low vision services in Wales and was effective.

Method: The impact of the WLVS was determined by measuring the number of low vision appointments; travel time to the nearest service provider; and waiting times for low vision services for 1 year before, and for 1 year after, its establishment. Change in self-report visual function (using the 7 item NEI-VFQ), near visual acuity, patient satisfaction and use of low vision aids were used to determine the effectiveness of the service.

Visual field loss in patients with refractory partial epilepsy treated with vigabatrin: final results from an open-label, observational, multicentre study.

Background: Use of the antiepileptic drug vigabatrin is associated with an elevated risk of visual field loss.

Objective: To determine the frequency of, and risk factors for, vigabatrin-attributed visual field loss (VAVFL) in the setting of a large-scale, multinational, prospective, observational study.

Study Design: A comparative, open-label, parallel-group, multicentre study.

Novel optometrist-led all Wales primary eye-care services: evaluation of a prospective case series.

Aims: To derive an evidence base for the efficacy of two novel optometric primary eye care services in Wales, the Primary Eyecare Acute Referral Scheme (PEARS) and the Welsh Eye Health Examination (WEHE).

Methods: A Donabedian model using structure, process and outcome was applied to evaluate prospectively 6432 individuals attending 274 optometrists within an 8-month period. Telephone interviews and review of optometric and hospital notes were used to determine management appropriateness for patients either managed in optometric practice or referred to the Hospital Eye Service (HES).

Vigabatrin and epilepsy: lessons learned.

Purpose: The risk factors for visual field loss attributable to vigabatrin (VAVFL) are equivocal. This multinational, prospective, observational study aimed to clarify the principal/major factors for VAVFL.

Methods: Interim analysis of three groups with refractory partial epilepsy, stratified by age (8-12 years; >12 years) and exposure to vigabatrin (VGB).

The relation between physical properties of the anterior eye and ocular surface temperature.

Purpose: To examine the relation between ocular surface temperature (OST) assessed by dynamic thermal imaging and physical parameters of the anterior eye in normal subjects.

Methods: Dynamic ocular thermography (ThermoTracer 7102MX) was used to record body temperature and continuous ocular surface temperature for 8 s after a blink in the right eyes of 25 subjects. Corneal thickness, corneal curvature, and anterior chamber depth (ACD) were assessed using Orbscan II; noninvasive tear break-up time (NIBUT) was assessed using the tearscope; slit lamp photography was used to record tear meniscus height (TMH) and objective bulbar redness.

Some dissociating factors in the analysis of structural and functional progressive damage in open-angle glaucoma.

Aim: To identify the presence, and origin, of any "dissociating factors" inherent to the techniques for evaluating progression that mask the relationship between structural and functional progression in open-angle glaucoma (OAG).

Methods: 23 patients (14 with OAG and 9 with ocular hypertension (OHT)) who had received serial Heidelberg Retina Tomograph (HRT II) and Humphrey Field Analyser (HFA) examinations for >or=5 years (mean 78.4 months (SD 9.

Detecting vigabatrin toxicity by imaging of the retinal nerve fiber layer.

Purpose: To quantify retinal nerve fiber layer thickness (RNFLT) and macular thickness (MT) in patients exhibiting vigabatrin-attributed visual field loss (VAVFL) and to determine the efficacy of these measures as markers of the retinal damage associated with vigabatrin.

Methods: This was a prospective cross-sectional observational study involving five groups: Group I, 13 patients exhibiting VAVFL; Group II, 8 patients exposed to vigabatrin but with normal fields; Group III, 14 patients receiving carbamazepine monotherapy; Group IV, 20 normal individuals; and Group V, 7 patients receiving sodium valproate monotherapy. At one of two visits, the right eye of each participant underwent two digital imaging modalities: ocular coherence tomography (OCT; StratusOCT; Carl Zeiss Meditec, Dublin, CA) and scanning laser ophthalmoscopy (SLO; Heidelberg Retinal Tomograph; Heidelberg Engineering GmbH, Heidelberg, Germany).

Evidence for a learning effect in short-wavelength automated perimetry.

Purpose: To document the magnitude of any learning effect for short-wavelength automated perimetry (SWAP) in patients with either ocular hypertension (OHT) or open-angle glaucoma (OAG) who are experienced in standard automated perimetry (SAP).

Design: Experimental study.

Participants: Thirty-five patients (22 with OHT and 13 with OAG) who had previously undergone at least 3 threshold SAP visual field examinations with the Humphrey Field Analyzer (HFA; Carl Zeiss Meditech Inc.

Neonatal development of the corneal stroma in wild-type and lumican-null mice.

Purpose: Between days 8 and 14 of neonatal development, the corneal stroma of the mouse undergoes critical changes in tissue thickness, cell density, and light scattering. The authors investigate the stromal matrix structure in wild-type and lumican-deficient corneas in this developmental phase.

Methods: Wild-type (n = 44) and lumican-deficient (n = 42) mouse corneas at neonatal days 8, 10, 12, and 14 were investigated by synchrotron x-ray diffraction to establish the average collagen fibril spacing, average collagen fibril diameter, and level of fibrillar organization in the stromal matrix.

Evaluation of the high specificity Screening Program (C-20-1) of the Frequency Doubling Technology (FDT) perimeter in clinical practice.

Aims: To compare the efficacy of the high specificity Frequency Doubling Technology (FDT) Perimeter Screening Program (C-20-1) to standard threshold automated perimetry in the diagnosis of open-angle glaucoma.

Methods: A total of 100 consecutively presenting patients attending a glaucoma clinic who volunteered for the study (approximately 30% of whom were attending for an initial visit) were examined with the FDT C-20-1 Screening Program and with the Humphrey Field Analyzer (HFA) SITA Fast algorithm and Program 24-2.

Results: Of the patients, 17 were excluded due to unreliable visual field results or non-glaucomatous ocular abnormalities.

X-ray scattering used to map the preferred collagen orientation in the human cornea and limbus.

Many properties of connective tissues are governed by the organization of the constituent collagen. For example, the organization of collagen in the cornea and the limbus, where the cornea and sclera meet, is an important determinant of corneal curvature and hence of the eye's focusing power. We have used synchrotron X-ray scattering to map the orientation of the collagen fibrils throughout the human cornea, limbus, and adjacent sclera.

An X-ray scattering investigation of corneal structure in keratocan-deficient mice.

The transparency of the cornea has been closely linked with the characteristic size and arrangement of its constituent collagen fibrils. This arrangement, in turn, is thought to depend on interactions with intervening matrix proteoglycans. The purpose of this investigation was to examine fibrillar collagen organisation in the corneas of mice homozygous for a null mutation in keratocan, a keratan sulfate-containing proteoglycan.