Publications by authors named "Emily Wiecek"

9 Publications

  • Page 1 of 1

Vergence, accommodation, and visual tracking in children and adolescents evaluated in a multidisciplinary concussion clinic.

Vision Res 2021 Apr 7;184:30-36. Epub 2021 Apr 7.

Boston Children's Hospital, Boston, MA 02115, United States; Harvard Medical School, Boston, MA 02115, United States.

Many patients with concussion experience visual symptoms following injury that lead to a diagnosis of convergence insufficiency, accommodative insufficiency, or saccadic dysfunction. However, these diagnostic categories are based on aggregates of clinical tests developed from a non-concussed population and therefore may not accurately describe visual deficits in the concussed population. Thus, we sought to understand individual metrics of visual dysfunction in chronically symptomatic post-concussion patients. This retrospective cross-sectional study included patients examined at the multidisciplinary concussion clinic (MDCC) at Boston Children's Hospital over four years. Patients aged 5-21 years who had a complete assessment of eye alignment, vergence, accommodation, and visual tracking, and had visual acuity better than or equal to 20/30 in each eye were included. Patients with history of amblyopia, strabismus, or ocular pathology were excluded. Chart review yielded 116 patients who met inclusion criteria (median age 15 years, 64% female). The majority of patients (52%) experienced a single concussion and most were sports-related (50%). Clinical data show vergence, accommodation, or visual tracking deficits in 95% of patients. A receded near point of convergence (NPC, 70/116) and reduced accommodative amplitude (63/116) were the most common deficits. Both NPC and accommodative amplitude were significantly correlated with one another (r = -0.5) and with measures of visual tracking (r = -0.34). Patients with chronic post-concussion symptoms show deficits in individual metrics of vergence, accommodation and visual tracking. The high incidence of these deficits, specifically NPC and accommodative amplitude, highlights the need for a detailed sensorimotor evaluation to guide personalized treatment following concussion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.visres.2021.03.002DOI Listing
April 2021

Clinical update on metamorphopsia: epidemiology, diagnosis and imaging.

Curr Eye Res 2021 Apr 7. Epub 2021 Apr 7.

NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom.

Purpose: To discuss the pathophysiology of metamorphopsia, its characterisation using retinal imaging and methods of assessment of patient symptoms and visual function.

Methods: A literature search of electronic databases was performedResults: Metamorphopsia has commonly been associated with vitreomacular interface disorders (such as epiretinal membrane) and has also regularly been noted in diseases of the retina and choroid, particularly age-related macular degeneration and central serous chorioretinopathy. Developments in optical coherence tomography retinal imaging have enabled improved imaging of the foveal microstructure and have led to the localisation of the pathophysiology of metamorphopsia within the retinal layers of the macula. Alteration of alignment of inner and outer retinal layers at various retinal loci has been identified using multimodal imaging in patients with metamorphopsia in a range of conditions. Although the Amsler Grid assessment of metamorphopsia is a useful clinical indicator, new emerging methods of metamorphopsia assessment with psychophysical tests such as M-CHARTS and preferential hyperacuity perimetry, have been developed.

Conclusions: It appears that there is a complex relationship between visual acuity and metamorphopsia symptoms that vary between retinal conditions. Although metamorphopsia has traditionally been challenging to measure in the clinic, advances in technology promise more robust, easy-to-use tests. It is possible that home assessment of metamorphopsia, particularly in conditions such as age-related macular degeneration, may help to guide the need for further clinic evaluation and consideration of treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/02713683.2021.1912779DOI Listing
April 2021

Spatial-frequency dependent binocular imbalance in amblyopia.

Sci Rep 2015 Nov 25;5:17181. Epub 2015 Nov 25.

Department of Psychology, Northeastern University, Boston, MA.

While amblyopia involves both binocular imbalance and deficits in processing high spatial frequency information, little is known about the spatial-frequency dependence of binocular imbalance. Here we examined binocular imbalance as a function of spatial frequency in amblyopia using a novel computer-based method. Binocular imbalance at four spatial frequencies was measured with a novel dichoptic letter chart in individuals with amblyopia, or normal vision. Our dichoptic letter chart was composed of band-pass filtered letters arranged in a layout similar to the ETDRS acuity chart. A different chart was presented to each eye of the observer via stereo-shutter glasses. The relative contrast of the corresponding letter in each eye was adjusted by a computer staircase to determine a binocular Balance Point at which the observer reports the letter presented to either eye with equal probability. Amblyopes showed pronounced binocular imbalance across all spatial frequencies, with greater imbalance at high compared to low spatial frequencies (an average increase of 19%, p < 0.01). Good test-retest reliability of the method was demonstrated by the Bland-Altman plot. Our findings suggest that spatial-frequency dependent binocular imbalance may be useful for diagnosing amblyopia and as an outcome measure for recovery of binocular vision following therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep17181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4658600PMC
November 2015

Metamorphopsia and letter recognition.

J Vis 2014 Dec 1;14(14). Epub 2014 Dec 1.

Massachusetts Eye and Ear Infirmary, Boston, MA, USA Department of Ophthalmology, Harvard Medical School, Boston, MA, USA Department of Psychology, Northeastern University, Boston, MA, USA.

Acuity is the most commonly used measure of visual function, and reductions in acuity are associated with most eye diseases. Metamorphopsia--a perceived distortion of visual space--is another common symptom of visual impairment and is currently assessed qualitatively using Amsler (1953) charts. In order to quantify the impact of metamorphopsia on acuity, we measured the effect of physical spatial distortion on letter recognition. Following earlier work showing that letter recognition is tuned to specific spatial frequency (SF) channels, we hypothesized that the effect of distortion might depend on the spatial scale of visual distortion just as it depends on the spatial scale of masking noise. Six normally sighted observers completed a 26 alternate forced choice (AFC) Sloan letter identification task at five different viewing distances, and the letters underwent different levels of spatial distortion. Distortion was controlled using spatially band-pass filtered noise that spatially remapped pixel locations. Noise was varied over five spatial frequencies and five magnitudes. Performance was modeled with logistic regression and worsened linearly with increasing distortion magnitude and decreasing letter size. We found that retinal SF affects distortion at midrange frequencies and can be explained with the tuning of a basic contrast sensitivity function, while object-centered distortion SF follows a similar pattern of letter object recognition sensitivity and is tuned to approximately three cycles per letter (CPL). The interaction between letter size and distortion makes acuity an unreliable outcome for metamorphopsia assessment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/14.14.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4249589PMC
December 2014

A statistical analysis of metamorphopsia in 7106 amsler grids.

Ophthalmology 2015 Feb 22;122(2):431-3. Epub 2014 Oct 22.

Schepens Eye Research Institute, Mass. Eye & Ear, Boston, Massachusetts; Harvard Medical School, Department of Ophthalmology, Boston, Massachusetts; Department of Psychology, Northeastern University, Boston, Massachusetts.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ophtha.2014.09.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4339289PMC
February 2015

Novel quantitative assessment of metamorphopsia in maculopathy.

Invest Ophthalmol Vis Sci 2014 Nov 18;56(1):494-504. Epub 2014 Nov 18.

Schepens Eye Research Institute/Mass. Eye and Ear, Boston, Massachusetts, United States Harvard Medical School, Department of Ophthalmology, Boston, Massachusetts, United States Department of Psychology, Northeastern University, Boston, Massachusetts, United States.

Purpose: Patients with macular disease often report experiencing metamorphopsia (visual distortion). Although typically measured with Amsler charts, more quantitative assessments of perceived distortion are desirable to effectively monitor the presence, progression, and remediation of visual impairment.

Methods: Participants with binocular (n = 33) and monocular (n = 50) maculopathy across seven disease groups, and control participants (n = 10) with no identifiable retinal disease completed a modified Amsler grid assessment (presented on a computer screen with eye tracking to ensure fixation compliance) and two novel assessments to measure metamorphopsia in the central 5° of visual field. A total of 81% (67/83) of participants completed a hyperacuity task where they aligned eight dots in the shape of a square, and 64% (32/50) of participants with monocular distortion completed a spatial alignment task using dichoptic stimuli. Ten controls completed all tasks.

Results: Horizontal and vertical distortion magnitudes were calculated for each of the three assessments. Distortion magnitudes were significantly higher in patients than controls in all assessments. There was no significant difference in magnitude of distortion across different macular diseases. There were no significant correlations between overall magnitude of distortion among any of the three measures and no significant correlations in localized measures of distortion.

Conclusions: Three alternative quantifications of monocular spatial distortion in the central visual field generated uncorrelated estimates of visual distortion. It is therefore unlikely that metamorphopsia is caused solely by retinal displacement, but instead involves additional top-down information, knowledge about the scene, and perhaps, cortical reorganization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.14-15394DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299468PMC
November 2014

Metamorphopsia and interocular suppression in monocular and binocular maculopathy.

Acta Ophthalmol 2015 Jun 1;93(4):e318-20. Epub 2014 Oct 1.

Schepens Eye Research Institute/Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/aos.12559DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408199PMC
June 2015

Effects of peripheral visual field loss on eye movements during visual search.

Front Psychol 2012 5;3:472. Epub 2012 Nov 5.

Massachusetts Eye and Ear Infirmary Boston, MA, USA ; Department of Ophthalmology, Harvard Medical School Boston, MA, USA ; Institute of Ophthalmology, University College London London, UK.

Natural vision involves sequential eye movements that bring the fovea to locations selected by peripheral vision. How peripheral visual field loss (PVFL) affects this process is not well understood. We examine how the location and extent of PVFL affects eye movement behavior in a naturalistic visual search task. Ten patients with PVFL and 13 normally sighted subjects with full visual fields (FVF) completed 30 visual searches monocularly. Subjects located a 4° × 4° target, pseudo-randomly selected within a 26° × 11° natural image. Eye positions were recorded at 50 Hz. Search duration, fixation duration, saccade size, and number of saccades per trial were not significantly different between PVFL and FVF groups (p > 0.1). A χ(2) test showed that the distributions of saccade directions for PVFL and FVL subjects were significantly different in 8 out of 10 cases (p < 0.01). Humphrey Visual Field pattern deviations for each subject were compared with the spatial distribution of eye movement directions. There were no significant correlations between saccade directional bias and visual field sensitivity across the 10 patients. Visual search performance was not significantly affected by PVFL. An analysis of eye movement directions revealed patients with PVFL show a biased directional distribution that was not directly related to the locus of vision loss, challenging feed-forward models of eye movement control. Consequently, many patients do not optimally compensate for visual field loss during visual search.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fpsyg.2012.00472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498877PMC
November 2012

Visual search with image modification in age-related macular degeneration.

Invest Ophthalmol Vis Sci 2012 Sep 25;53(10):6600-9. Epub 2012 Sep 25.

Massachusetts Eye and Ear Infirmary, 20 Staniford Street, Boston, MA 02118, USA.

Purpose: AMD results in loss of central vision and a dependence on low-resolution peripheral vision. While many image enhancement techniques have been proposed, there is a lack of quantitative comparison of the effectiveness of enhancement. We developed a natural visual search task that uses patients' eye movements as a quantitative and functional measure of the efficacy of image modification.

Methods: Eye movements of 17 patients (mean age = 77 years) with AMD were recorded while they searched for target objects in natural images. Eight different image modification methods were implemented and included manipulations of local image or edge contrast, color, and crowding. In a subsequent task, patients ranked their preference of the image modifications.

Results: Within individual participants, there was no significant difference in search duration or accuracy across eight different image manipulations. When data were collapsed across all image modifications, a multivariate model identified six significant predictors for normalized search duration including scotoma size and acuity, as well as interactions among scotoma size, age, acuity, and contrast (P < 0.05). Additionally, an analysis of image statistics showed no correlation with search performance across all image modifications. Rank ordering of enhancement methods based on participants' preference revealed a trend that participants preferred the least modified images (P < 0.05).

Conclusions: There was no quantitative effect of image modification on search performance. A better understanding of low- and high-level components of visual search in natural scenes is necessary to improve future attempts at image enhancement for low vision patients. Different search tasks may require alternative image modifications to improve patient functioning and performance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.12-10012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3460389PMC
September 2012