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BACKGROUND: Visual dysfunctions are common in individuals following concussion/mild traumatic brain injury (C/mTBI). Many deficits have been uncovered in their oculomotor system, such as in the pupil and accommodation. OBJECTIVE: To describe the static and dynamic abnormalities in the pupillary and accommodative systems in those with C/mTBI. This includes both diagnostic and therapeutic aspects, with emphasis on objectively-based test findings, as well as their basic and clinical ramifications. METHODS: PubMed, Google Scholar, and Semantic Scholar databases were searched from 1980–2020, using key words of accommodation, pupil, vision therapy, vision rehabilitation, and objective testing, for peer-reviewed papers, as well as related textbooks in the area, in those with C/mTBI. RESULTS: For both systems, most static and dynamic response parameters were abnormal: they were typically reduced, slowed, delayed, and/or more variable. Most of the abnormal accommodative parameters could be significantly improved with vision therapy. CONCLUSIONS: For both systems, most response parameters were abnormal, which could explain their visual symptoms and related problems. For accommodation, the improvements following vision therapy suggest the presence of considerable visual system plasticity, even in older adults with chronic brain injury.

SIGNIFICANCE Visual performance is affected least by a 15° radial aperture surrounded by peripheral myopic defocus. This finding has important applications for spectacle and contact lens designs and myopia control optimization. PURPOSE The purpose of this study was to assess the effect of clear central apertures of different diameters with a defocused retinal periphery, using a range of visual performance tasks. METHODS Thirty visually normal subjects (mean age, 24.4 ± 3.3 years; 20 females; mean spherical equivalent of -1.28 D) were enrolled. Subjects wore five different spectacles during testing, all corrected for distance refraction, in random order: three single-vision spectacles with clear central apertures of 10, 12.5, and 15° radii with the periphery defocused using Fresnel "press-on" lenses (+3.5 D sphere), progressive addition lens (PAL) spectacles with a +3.5 D addition, and single-vision lens (SVL) spectacles with no peripheral defocus. Static and kinetic visual field sensitivities, reading rate and comprehension, head movements, global saccadic tracking, and saccadic visual search were evaluated. RESULTS Reading rate and comprehension did not differ across the five test conditions; however, increased head movement was found with the smallest aperture compared with the PAL condition with adjusted P < .05. Static visual field sensitivity was reduced for all three apertures in eccentric regions when compared with the SVL and PAL conditions with adjusted P < .05, whereas kinetic sensitivity did not differ for any lens condition. The 15° aperture was superior to the 10 and 12.5° apertures based on its similarity to the SVL and PAL spectacle conditions in head movement during reading, the Michigan Tracking Test, and the vertical results of the Developmental Eye Movement Test. CONCLUSIONS Visual performance is least affected adversely by a 15° aperture surrounded by a peripheral myopic defocus. This finding has important applications for spectacle and contact lens designs to optimize myopia treatment with minimal impact on visual performance.

Purpose To investigate the impact of eye exercises of acupoints on myopic progression among Chinese urban students. Methods The Beijing Myopia Progression Study (BMPS) was a three-year cohort study, with 386 students (aged 6-17 years) enrolled at baseline. These students were invited to be reexamined in the years 2011, 2012, and 2013. The student's cycloplegic refraction at each visit and the parental non-cycloplegic refraction at baseline were performed. Students were also required to complete the eye exercise of acupoints questionnaire and the convergence insufficiency symptom survey (CISS). Results At the final follow-up, 226 students (57.2%) with complete refraction and eye exercises questionnaire data were enrolled in the present study. In the multivariate analysis, only students who performed the eye exercises twice or more per day had less myopic refractive change (β=0.32, p=0.04), as compared to those who performed the eye exercises less than twice per day. No significant association was found between the CISS score and the refractive change for items in the eye exercises questionnaire. Conclusion In this study cohort, the Chinese eye exercises of acupoints had a modest effect on reducing myopic progression among Chinese urban students aged 6 to 17 years. The precise mechanism remains unclear, especially in the absence of a control group.

Purpose To investigate the natural change of nearwork-induced transient myopia (NITM), and its association with the progression of refractive error. Methods Students of the Beijing Myopia Progression Study were examined at baseline and follow-up examinations, which included cycloplegic autorefraction. Initial NITM and its decay were assessed objectively immediately after binocularly-viewing and performing a sustained 5-minute near task (20 cm). Results There were 223 students with both NITM and cycloplegic refractive data enrolled. There were 142 myopic (63.7%), 32 emmetropic (14.4%), and 49 hyperopic (22.0%) students according to their baseline cycloplegic refraction. The annual refractive change was −0.45 (−0.73, −0.21) D. From the baseline to the one-year and two-year follow-up periods, the initial NITM (median) increased significantly in the myopic students (0.16, 0.21, and 0.20D, p = 0.01, respectively). The overall proportion of NITM decay types shifted significantly from none being induced at baseline (non-induced: 17.0%, complete decay 57.4%, incomplete decay 25.6%) to incomplete decay at the 2-year follow-up (non-induced: 6.7%, complete decay 65.0%, incomplete decay 28.3%, p = 0.01). For the hyperopic students, after adjusting for risk factors, for every 1 diopter increase in the initial NITM at baseline, there was approximately a −1.48 diopter more relative myopic refractive progression (p = 0.01). No significant association was found between refractive change and the NITM parameters for either the myopic or emmetropic students after adjusting for the same confounders. However, this relation was significant in the hyperopes (p = 0.01). Conclusion NITM was only found to be significantly associated with the progression of a myopic refractive shift among the hyperopes.

Visual snow syndrome (VSS) is a relatively rare, unusual, and disturbing abnormal visual condition. The individual perceives “visual snow” (VS) throughout the entire visual field, as well as other abnormal visual phenomena (e.g., photopsia). Only relatively recently has treatment been proposed (e.g., chromatic filters) in adults with VSS, but rarely in the pediatric VSS population (i.e., medications). In this paper, we present three well-documented cases of VSS in children, including their successful neuro-optometric therapeutic interventions (i.e., chromatic filters and saccadic-based vision therapy)

Vergence and accommodation have been critical areas of investigation in those with mild traumatic brain injury (mTBI). In this mini-review, the major laboratory studies in the area using objective assessment of vergence and accommodative dynamics in this population are discussed. These include the basic findings, their diagnostic and therapeutic implications, potential study limitations, and suggested future research directions. All studies provided important new information, and insights, into the area. There were two key outcomes of the reviewed studies common to both the vergence and accommodative systems in those with mTBI. First, most dynamic parameter's responsivity at baseline was abnormal: it was slowed, delayed, and/or inaccurate as compared to the normative control data. Second, most of the abnormal dynamic parameter's responsivity could be remediated, at least in part, following a short period of oculomotor-based vision therapy, thus demonstrating considerable residual neuroplasticity in the damaged, human brain.

Background: A potential objective measure that may assist in identifying vision disorders after concussion is the pupillary light reflex (PLR), which is under autonomic control and contributes to normal convergence and accommodative function which is altered after concussion. This study sought to compare pupillometry measures in adolescents with concussion initially presenting for care in the early acute time frame (≤ 2 weeks post-concussion) to those presenting in the later acute time frame (4 ± 1 weeks). Hypothesis: To determine whether PLR metrics are similar or different between athletes with concussion presenting earlier (≤ 2 weeks post-concussion) for care vs. those presenting later for care (4 ± 1 weeks). Methods: Athletes, ages 12-18 years, with a diagnosis of sport-related concussion (n = 110) were recruited. 89 concussed subjects had their PLR assessment performed at an early acute time point ≤ 2 weeks after concussion, while 21 concussed subjects had their first assessment at a later acute time point (4 week±1 week). Pupillary dynamics were measured in response to a brief, step-input, white light stimulus (154 ms duration; 180 micro watts power) via a Neuroptics PLR-3000 hand-held, infrared, automated, monocular pupillometer (Neuroptics, Irvine, CA). The means of the PLR metrics were compared between groups with one-way Student’s t test. Bonferroni correction was applied. Results: The baseline pupil diameter (mean ± SD) was significantly larger (pConclusion: When comparing adolescents with concussion presenting early in the acute phase ≤ 2 weeks after concussion to those presenting later in the acute timeframe to care 4±1 weeks, those presenting later demonstrate enhancement of certain PLR metrics, namely larger baseline pupil diameter and faster average constriction velocity (ACV) and maximum constriction velocity (MCV). Differences in these PLR metrics in those presenting later in the acute timeframe may represent findings in those who are more likely to have persisting post-concussion symptoms, potentially shedding light on pathophysiological underpinnings of lingering symptoms.

Importance Concussion diagnosis remains clinical, without objective diagnostic tests available for adolescents. Known deficits in visual accommodation and autonomic function after concussion make the pupillary light reflex (PLR) a promising target as an objective physiological biomarker for concussion. Objective To determine the potential utility of PLR metrics as physiological biomarkers for concussion. Design, Setting, and Participants Prospective cohort of adolescent athletes between ages 12 and 18 years recruited between August 1, 2017, and December 31, 2018. The study took place at a specialty concussion program and private suburban high school and included healthy control individuals (n = 134) and athletes with a diagnosis of sport-related concussion (SRC) (n = 98). Analysis was completed June 30, 2020. Exposures Sports-related concussion and pupillometry assessments. Main Outcomes and Measures Pupillary light reflex metrics (maximum and minimum pupillary diameter, peak and average constriction/dilation velocity, percentage constriction, and time to 75% pupillary redilation [T75]). Results Pupillary light reflex metrics of 134 healthy control individuals and 98 athletes with concussion were obtained a median of 12.0 days following injury (interquartile range [IQR], 5.0-18.0 days). Eight of 9 metrics were significantly greater among athletes with concussion after Bonferroni correction (maximum pupil diameter: 4.83 mm vs 4.01 mm; difference, 0.82; 99.44% CI, 0.53-1.11; minimum pupil diameter: 2.96 mm vs 2.63 mm; difference, 0.33; 99.4% CI, 0.18-0.48; percentage constriction: 38.23% vs 33.66%; difference, 4.57; 99.4% CI, 2.60-6.55; average constriction velocity: 3.08 mm/s vs 2.50 mm/s; difference, 0.58; 99.4% CI, 0.36-0.81; peak constriction velocity: 4.88 mm/s vs 3.91 mm/s; difference, 0.97; 99.4% CI, 0.63-1.31; average dilation velocity, 1.32 mm/s vs 1.22 mm/s; difference, 0.10; 99.4% CI, 0.00-0.20; peak dilation velocity: 1.83 mm/s vs 1.64 mm/s; difference, 0.19; 99.4% CI, 0.07-0.32; and T75: 1.81 seconds vs 1.51 seconds; difference, 0.30; 0.10-0.51). In exploratory analyses, sex-based differences were observed, with girls with concussion exhibiting longer T75 (1.96 seconds vs 1.63 seconds; difference, 0.33; 99.4% CI, 0.02-0.65). Among healthy control individuals, diminished PLR metrics (eg, smaller maximum pupil size 3.81 mm vs 4.22 mm; difference, −0.41; 99.4% CI, −0.77 to 0.05) were observed after exercise. Conclusions and Relevance These findings suggest that enhancement of PLR metrics characterize acute adolescent concussion, while exercise produced smaller pupil sizes and overall slowing of PLR metrics, presumably associated with fatigue. Quantifiable measures of the PLR may serve in the future as objective physiologic biomarkers for concussion in the adolescent athlete.

PurposeTo assess the refractive change and incidence of myopia, as well as their risk factors, among Chinese rural children aged 6–17 years.MethodsChildren who completed the baseline vision examination of the Handan Offspring Myopia Study were re-examined, including both cycloplegic and non-cyloplegic autorefraction, with a mean follow-up time of 42.4±1.47 months.ResultsA total of 601 children (68.5%) who completed both baseline and the follow-up examinations were enrolled. The cumulative refractive change and axial length change were −0.53±1.03 diopter and 0.39±0.46 mm (−0.15 diopter/year and 0.11 mm/year), respectively. A hundred and five out of the 469 non-myopic children at baseline become myopic at the follow-up, yielding a cumulative myopia incidence of 22.4% (95% CI: 18.6% to 26.2%), or annual myopia incidence of 6.3%. After adjustment, younger age (β=0.08, pConclusionRelatively low myopic refractive change and myopia incidence were found in this study cohort. Children’s refraction and paternal refraction were associated with both myopic refractive change and myopia incidence. Such information will be helpful for further comparisons in other rural versus urban areas of China, and other countries.

To investigate the relationship between visual resolution and cone parameters in eyes with different levels of best corrected visual acuity (BCVA). Seventeen eyes of 10 volunteers with BCVA of 20/12.5 or better (group 1) and 16 eyes of 10 volunteers with BCVA of 20/16 (group 2) were investigated in the study. Images of the cone photoreceptors at 1.5° from the fovea were obtained using an adaptive optics (AO) retinal camera. The BCVA was obtained following a subjective refraction using a standardized logMAR visual acuity chart. The mean cone density (29,570.96 ± 2489.94 cells/mm2) at 1.5° from the fovea in group 1 (BCVA ≥ 20/12.5, n = 17) was significantly greater (P

Purpose To assess the prevalence of esophoria at near in concussed patients in a neuro-optometric private practice setting. Methods A retrospective analysis was performed involving a chart review in a neuro-optometric, private practice setting of consecutive patients with a medical diagnosis of concussion from January 1st 2016 to December 31st 2016. A total of 71 patients were included in the analysis. All received a comprehensive vision examination, with a near vision emphasis. The near horizontal phoria was assessed with the cover test and the von Graefe test. Results Approximately 30% of the patients with a medically based diagnosis of concussion exhibited esophoria at near, with good agreement (95%) between the two tests. Mean esophoria was 5.2 (SD = 2.8) prism diopters (pd), with a range from 2pd to 14pd of esophoria. Convergence excess was diagnosed in 23%. Discussion Near esophoria was found in nearly one-third of this practice-based sample of concussed patients. Thus, it was more common than typically believed to be the case. Two proposed oculomotor-based mechanisms related to these symptomatic esophoric patients included phoria decompensation and excessive accommodative vergence.

Purpose: This pilot study sought to determine the efficacy of using the Developmental Eye Movement (DEM) test in the adult, acquired brain injury (ABI) population to quantify clinically the effects of controlled, laboratory-performed, oculomotor-based vision therapy/vision rehabilitation. Methods: Nine adult subjects with mild traumatic brain injury (mTBI) and five with stroke were assessed before and after an eight-week, computer-based, versional oculomotor (fixation, saccades, pursuit, and simulated reading) training program (9.6 h total). The protocol incorporated a cross-over, interventional design with and without the addition of auditory feedback regarding two-dimensional eye position. The clinical outcome measure was the Developmental Eye Movement (DEM) test score (ratio, errors) taken before, midway, and immediately following training. Results: For the DEM ratio parameter, improvements were found in 80–89% of the subjects. For the DEM error parameter, improvements were found in 100% of the subjects. Incorporation of the auditory feedback component revealed a trend toward enhanced performance. The findings were similar for both DEM parameters, as well as for incorporation of the auditory feedback, in both diagnostic groups. Discussion: The results of the present study demonstrated considerable improvements in the DEM test scores following the oculomotor-based training, thus reflecting more time-optimal and accurate saccadic tracking after the training. The DEM test should be considered as another clinical test of global saccadic tracking performance in the ABI population. Resumen: Objetivo: Este estudio piloto trató de determinar la eficacia del uso de la prueba DEM (Developmental Eye Movement) en la población adulta con daño cerebral adquirido (DCA) para cuantificar clínicamente los efectos de la rehabilitación/terapia visual controlada, realizada en laboratorio, y de carácter oculomotor. Métodos: Se valoraron nueve sujetos adultos con daño cerebral traumático leve (mTBI) y cinco con ictus, con anterioridad y posterioridad a un programa de entrenamiento de ocho semanas, informático oculomotor y versional (movimientos de fijación, sacádicos, de persecución y lectura simulada, de 9,6 horas en total). El protocolo incorporó un diseño cruzado e intervencional, con y sin adición de retroalimentación auditiva en relación a la posición bi-dimensional de los ojos. La medida del resultado clínico se llevó a cabo mediante la puntuación de la prueba DEM (Developmental Eye Movement) (ratio, errores) realizada con anterioridad, en el punto medio, e inmediatamente tras el entrenamiento. Resultados: Para el parámetro de ratio DEM, se encontraron mejoras en el 80-89% de los sujetos. Para el parámetro de error DEM, se encontraron mejoras en el 100% de los sujetos. La incorporación del componente de retroalimentación auditiva reveló una tendencia hacia la mejora del rendimiento. Los hallazgos fueron similares para ambos parámetros DEM, así como para la incorporación de la retroalimentación auditiva, en ambos grupos diagnósticos. Discusión: Los resultados del presente estudio demostraron mejoras considerables de las puntuaciones de la prueba DEM tras la terapia oculomotora, lo que refleja una mayor optimización y precisión del seguimiento sacádico en el tiempo tras la terapia. Deberá considerarse la prueba DEM como una prueba clínica para valorar el rendimiento del seguimiento sacádico global en la población de DCA. Keywords: Traumatic brain injury (TBI), Cerebral vascular accident (CVA)/stroke, Developmental Eye Movement (DEM) test, Eye movements, Neuro-optometric rehabilitation, Palabras clave: Daño cerebral traumático (DCT), Accidente cerebro-vascular (ACV)/ictus, Prueba DEM (Developmental Eye Movement), Movimientos oculares, Rehabilitación neuro-optométrica

PURPOSE The SVOne is a portable, Hartmann-Shack wavefront aberrometer, which can be attached to a smartphone to determine the refractive error of the eye objectively. Previous results have shown the device to provide measurements equivalent to those of standard clinical techniques in young, healthy adults. The aim of the present study was to compare the findings of the SVOne with retinoscopy, subjective refraction, and two commercially available autorefractors (Retinomax-3 and WAM-5500) in a pediatric population. METHOD The refractive error of the right eye was assessed both without and with cycloplegia in 40 visually normal children between 5 and 17 years of age (mean age = 11.3 years) using the five techniques described above. Further, to assess repeatability of the instruments, the entire procedure was repeated in a subgroup of five subjects. All data were analyzed in terms of power vectors (M, J0, and J45). RESULTS No significant difference was observed between the mean values of M (spherical equivalent) for the different techniques. Retinoscopy showed the best agreement with subjective refraction, both without and with cycloplegia, followed by the open-field WAM-5500. The most repeatable procedures, when measured without and with cycloplegia, were the WAM-5500 and retinoscopy, respectively. Measurements with the SVOne showed a decline in repeatability under cycloplegia. CONCLUSIONS The results indicate that the SVOne provides measurements of refractive error in a normal, pediatric population that are not significantly different from other subjective and objective procedures. Accurate alignment along the visual axis, especially when measuring through a dilated pupil, is critical. This instrument is valuable for vision screenings, for examinations taking place outside the clinical office, and a starting point for the refractive assessment.

To determine if mTBI adversely affects the pupillary light reflex (PLR).The PLR was evaluated in mTBI and compared to normal individuals under a range of test conditions. Nine pupil parameters (maximum, minimum and final pupil diameter, latency, amplitude and peak and average constriction and dilation velocities) and six stimulus conditions (dim pulse, dim step, bright pulse, bright step, bright red step and bright blue step) were assessed in 32 adults with mTBI (21-60 years of age) and compared to 40 normal (22-56 years of age). The Neuroptics, infrared, DP-2000 binocular pupillometer was used (30 Hz sampling rate; 0.05 mm resolution) with binocular stimulation and recording.Different test conditions allowed for discrimination of different parameters. For any of the given six test conditions, five-to-eight of the nine pupillary parameters were statistically different (p0.05) between the two diagnostic groups. The most promising parameters for diagnostic differentiation were constriction latency, all pupillary diameters, average constriction velocity and peak dilation velocity.MTBI adversely affects the PLR. This suggests an impairment of the autonomic nervous system. The findings suggest the potential for quantitative pupillary dynamics to serve as an objective mTBI biomarker.

Little is known about human inter-ocular pupillary asymmetry (IOPA). Thus, the purpose of the present investigation was to assess objectively static and dynamic IOPA in normals and in individuals with mild traumatic brain injury (mTBI).The pupillary light reflex (PLR) was assessed in an adult population of normals and in those with mTBI using the Neuroptics DP-2000 binocular pupillometer. Four stimulus conditions were used to optimize the assessment. Two aspects of the pupil were assessed: baseline diameter prior to light stimulation and the dynamic amplitude of constriction following light stimulation.There was no statistical difference in either the static or dynamic IOPA between the two groups. Thus, the data were combined for a better global parameter estimate. The mean average static IOPA was 0.26 mm (SD = ± 0.20 mm) or 4.17% (± 3.29%). The mean average dynamic IOPA was dependent on the light stimulus condition, with the average across all four test conditions being 0.11 mm (± 0.10 mm) or 1.84% (± 1.70%).The inter-ocular pupillary effects of mTBI appear to be symmetrical rather than asymmetrical in nature. The findings provide clinicians and researchers a useful quantitative guideline to assess normal vs abnormal static and dynamic inter-ocular pupillary asymmetry (IOPA) in these two populations.

To investigate the influence of daily activities on myopic refractive change and myopic onset in Chinese urban students. The Beijing Myopia Progression Study was a 3-year cohort study. Cycloplegic refraction and a daily activity questionnaire were assessed at baseline and at follow-up examinations. Refractive change was defined as the difference in cycloplegic spherical equivalent (SE) between the final follow-up and baseline. 386 students were initially enrolled in the baseline study. At the final follow-up, 222 students (57.5 %) with completed refractive error and daily activity data were analyzed. These students spent 0.32 ± 2.33 h/day more on near work (p = 0.04), and 0.21 ± 1.31 h/day less on outdoor leisure (p = 0.02), than they did at baseline. In the multivariate analysis, the younger among the secondary students (β = 0.06, p

OBJECTIVES To develop a clinical protocol for the determination of eye dominance using an objective method (i.e., the visual evoked potential [VEP]), and furthermore to determine the correlation of these objective findings with clinical subjective tests of eye dominance to provide guidance in clinical monovision refractive correction. METHODS The Diopsys NOVA-TR system was used to record the VEP amplitude and latency of 10 visually-normal, presbyopic, adult subjects aged 50 to 70 years ((Equation is included in full-text article.)=60, SEM=0.17 years). First, eye dominance was assessed in two ways: a sensory-based "sensitivity to blur task" and a motor-based "sighting task." Next, while monocularly defocused, subjects binocularly viewed a black-and-white checkerboard (20-min arc size), pattern-reversal stimulus under 7 different test conditions: (1) baseline, (2) dominant (DE) eye blurred +1 diopter (D), (3) nondominant (NDE) eye blurred +1 D, (4) DE +2 D, (5) NDE +2 D, (6) DE +3 D, and (7) NDE +3 D. RESULTS Under nearly all conditions (22/24=92%), the amplitude and latency were significantly different from baseline with any amount of defocus (P

The aim was to assess non-cycloplegic objective refraction in darkness using an open-field auto-refractor, and furthermore to compare it with distance cycloplegic subjective refraction and distance cycloplegic retinoscopy in the light, in children and young adults.Twenty-three, visually-normal, young-adults (46 eyes) ages 23 to 31 years, and five children (10 eyes) ages five to 12 years, participated in the study. The spherical component of their refraction ranged from -2.25 D to +3.75 D with a mean of +1.80 D, and a mean cylinder of -0.70 D. Three techniques were used to assess refractive error. An objective measure of the non-cycloplegic refractive state was obtained using an open-field autorefractor (WAM-5500) after five minutes in the dark to allow for dissipation of accommodative transients and relaxation of accommodation. In addition, both distance retinoscopy and subjective distance refraction were performed following cycloplegia (Cyclopentolate, 1%) using conventional clinical procedures. All measurements were obtained on the same day within a single session. The spherical component of the refraction was compared among the three techniques in both the children and adults.There was no significant difference in spherical refraction among the three techniques: non-cycloplegic objective refraction in the dark, distance cycloplegic retinoscopy and distance cycloplegic subjective refraction, in either the adults [F(2, 137) = 0.79, p = 0.45] or the children [F(2, 27) = 0.47, p = 0.62]. Mean difference in the spherical component between refraction in the dark and the cycloplegic distance retinoscopy was -0.34 D (r = 0.89) in the adults and +0.14 D (r = 0.96) in the children. The mean difference in spherical component between refraction in the dark and the cycloplegic distance subjective refraction was -0.25 D (r = 0.92) in the adults and -0.05 D (r = 0.95) in the children.Comparison of the spherical refractive component between the three techniques was not significantly different and furthermore, they were highly correlated in both the children and adults in this pilot study. Non-cycloplegic refraction in the dark may provide a reliable adjunct or alternative to conventional cycloplegic refraction in both children and young adults.

Purpose. To compare the axial length difference (ALD) and the estimated generational axial length shift (ALS) from parents to their children and its risk factors in urban and rural China. Methods. Participants were enrolled from two longitudinal cohort studies, the Beijing Myopia Progression Study (BMPS) and the Handan Offspring Myopia Study (HOMS). Ocular biometry was performed in both parents and their children. ALD was defined as the difference between the children’s axial length and the corresponding parental axial length. Generational ALS was estimated according to a binominal prediction model at 18 years of age. Results. 237 and 380 urban and rural Chinese children (6–17 years) and their parents from the BMPS and HOMS, respectively, were enrolled. Children’s axial length was estimated to be closest to the parental axial length at 11 and 9 years of age in the urban and rural areas, respectively; the estimated generational ALS would be 1.53 and 0.57 mm, respectively. Multivariable regression analysis revealed that older children (urban β = 0.26, p<0.001; rural β = 0.11, p<0.001) and males had larger ALD (urban β = 0.55, p<0.001; rural β = 0.52, p<0.001) in both areas. Furthermore, urban children with more educated parents (fathers: β = −0.30, p=0.002; mothers: β = −0.29, p=0.004) and more outdoor activity (β = −0.23, p=0.006) had a less ALD. Conclusions. The urban generational axial length shift was estimated to be approximately 1 mm longer than that of the rural area. These results suggest different environmental effects on the ocular development in these two populations of Chinese children.

Background: Despite advancements, concussion diagnosis remains reliant on subjective symptom report and clinical assessments. Visual deficits and autonomic dysfunction have been described following concussion. Testing of the pupillary light reflex (PLR) is a simple, portable, non-invasive, and objective means of quantifying pupillary function. Purpose: The aim of this study was to objectively evaluate pupillary responses to a light stimulus in concussed adolescent athletes and to determine whether clinical assessments correlated with PLR responses after a diagnosed concussion when compared to pre-injury responses. Methods: In this prospective cohort study, PLR and clinical measures [PCSI and/or SCAT symptom scales, near point of convergence (NPC) and accommodation amplitude (AA) of both eyes] were assessed in 93 (45 female), non-concussed adolescent athletes (ages 14-18) during their pre-season. PLR was obtained in response to a brief white light stimulus using a hand-held pupillometer. During each assessment, three monocular trials were performed in each eye alternatively, with subsequent averaged responses for each eye. Seven athletes (ages 14-17) sustained a concussion and had post-injury assessments of PLR and clinical measures completed longitudinally through recovery. Results: All seven concussed athletes completed PLR and clinical assessments at least once post-injury (mean initial day of evaluation = 6 days post injury). Six out of the seven concussed athletes demonstrated an increase in steady state diameter of 24% (median 18%), minimum pupil diameter of 17% (median 11%) and a maximum constriction velocity of 28% (median 33%) following concussion which decreased over the course of recovery, returning to pre-injury or below pre-injury measurements. Six of seven of the concussed athletes completed NPC and AA assessments at both pre-season and post-injury timepoints. In contrast to the PLR findings, both NPC and AA measures were normal at post-injury assessments. Reported symptom scores improved throughout recovery, correlating with PLR response recovery, with both returning to pre-injury measurements. Conclusion: Pupil responsivity was found to be significantly enhanced after concussion compared to pre-injury measurements, waning over time during recovery, following a similar trajectory as symptom burden. NPC and AA, which have autonomic contributions and are clinical measures, were normal pre- and post-injury and did not differentiate the concussed state from the uninjured state in our series. Our preliminary results demonstrate that dynamic PLR responses may detect acute autonomic deficits that are not evident via clinical assessments. Further investigation of its potential utility as sensitive and objective biomarker in concussion diagnosis, management and sports clearance is warranted.

To evaluate objectively and quantitatively human pupillary responses to a light stimulus under photopic conditions in individuals with non-blast-induced, chronic, mild traumatic brain injury (mTBI).Seventeen individuals with chronic, non-blast-induced mTBI and 15 visually-normal (VN) controls were tested (aged 21-45 years). Pupillary responsivity to a brief step-input light stimulus was assessed objectively in each eye for 5 seconds using the Neuroptics PLR-200 monocular, hand-held pupillometer with its pre-set and automated eight parameter analysis.Five of the eight parameters assessed were significantly reduced (p ≤ 0.05) in the mTBI group as compared to the VN control group: maximum (or peak) constriction velocity, average constriction velocity, average dilation velocity, maximum diameter and amplitude of constriction. The remaining three parameters were similar in each group (p 0.05): constriction latency, 75% dilation recovery time and minimum diameter.The slowed dilation dynamics and reduced maximum pupillary diameter in mTBI suggest deficiency primarily of the sympathetic control system. The reduced peak velocities and related amplitudes suggest subtle parasympathetic involvement.

Vision plays a critical role in athletic performance; however, previous studies have demonstrated that a variety of simulated athletic sensorimotor tasks can be surprisingly resilient to retinal defocus (blurred vision). The purpose of the present study was to extend this work to determine the effect of retinal defocus on overall basketball free throw performance, as well as for the factors gender, refractive error and experience.Forty-four young adult participants of both genders were recruited. They had a range of refractive errors and basketball experience. Each performed 20 standard basketball free throws under five lens defocus conditions in a randomised manner: plano, +1.50 D, +3.00 D, +4.50 D and +10.00 D.Overall, free throw performance was significantly reduced under the +10.00 D lens defocus condition only. Previous experience, but neither refractive error nor gender, yielded a statistically significant difference in performance.Consistent with previous studies of complex sensorimotor tasks, basketball free throw performance was resilient to low and moderate levels of retinal defocus. Thus, for a relatively non-dynamic motor task at a fixed far distance, such as the basketball free throw, precise visual clarity was not critical. Other factors such as motor memory may be important. However, in the dynamic athletic competitive environment it is likely that visual clarity plays a more critical role in one's performance level, at least for specific task demands.

The challenge and search for objectively based biomarkers to assess for the presence of concussion/mild traumatic brain injury is a high priority for the military establishment. We present a documented overview of specific test areas and related targeted, high-yield, objectively based parameters that may be potential “vision biomarkers” for the detection of concussion/mild traumatic brain injury based on results from our laboratory and others, with emphasis on oculomotor aspects. These findings have military relevance with respect to the initial diagnosis in the battlefield and in the far-forward medical facilities, pre-/postdeployment issues, pre-/postvisual rehabilitation evaluation, fitness-for-duty assessment, and establishment of a return-to-duty timeline.

Purpose: To investigate retrospectively, based on routine clinical records in an optometric office, the effect of refractive under-correction of the myopic spectacle prescription on myopic progression in children and young adults. Methods: Patient records of children and young-adult myopes in a private optometric practice in Glendale, Arizona, USA, were initially reviewed to identify those that met the criteria. Information collected from the patient records included: age, gender, the dates and number of their visits (more than one visit was required for use of the data), final prescription, and non-cycloplegic subjective refraction. For each patient visit, the difference in spherical equivalent (SE) between the subjective refraction for maximum visual acuity and the final prescription was calculated for both the left and right eyes. Myopia progression was defined as the difference in SE between the final subjective refraction of the previous visit and that of the subsequent visit. Based on the study criteria, a total of 275 patient visits were obtained from the data collected in 76 patients. Results: A significant positive correlation was found between the magnitude of under-correction of the refractive error and myopic progression (r = 0.301, p