Concussion-Related Vision Disorder Practice Patterns in Occupational Therapy: A Survey

Background: Occupational therapists are among the first providers to initiate care after a concussion; however, evidence is limited regarding current concussion-related vision disorder practice patterns. A better understanding of these practice patterns is important because of the impact of undetected and untreated vision problems on occupational performance. Method: A mixed-methods survey was administered online to occupational therapists to explore the assessments and interventions used to address concussion-related vision disorders, occupational therapy’s perceived role, and difficulties encountered when treating these conditions. Results: Of 23,910 occupational therapists invited to participate, 2,278 (10%) began the survey, and 1,187 (52%) met inclusion criteria. Assessment tools identified were subjective and objective in nature. Identification and treatment varied significantly based on years of practice, whether an optometrist was on site, and whether vision continuing education was completed. Identified roles included ADLs, compensation, and identification. Treatment difficulties included resources, education, and evidence. Conclusion: Data revealed inconsistent practice patterns, perhaps because of educational differences. The results suggested improving education in the areas of concussion and vision by developing interprofessional collaboration and standards of care, developing a vision remediation certification, and producing further research regarding concussion-related vision disorders and occupation in the occupational therapy literature

Vergence fusion sustaining oscillations

Introduction:  Previous studies have shown that the slow, or fusion sustaining, component of disparity vergence contains oscillatory behavior.  Given the delays in disparity vergence control, a feedback control system would be expected to exhibit oscillations following the initial transient period.  This study extends the examination of this behavior to a wider range of frequencies and a larger number of subjects.  Methods:  Disparity vergence responses to symmetrical 4.0 deg step changes in target position were recorded in 15 subjects. Approximately three seconds of the late component of each response were isolated using interactive graphics and the frequency spectrum calculated.  Peaks in these spectra associated with oscillatory behavior were identified and examined.  Results: All subjects exhibited oscillatory behavior with primary frequencies ranging between 0.45 and 0.6 Hz; much lower than those identified in the earlier study.  All responses showed significant higher frequency components.  These higher frequency components were related in both frequency and amplitude with the primary frequency indicating that they are harmonics probably generated by nonlinearities in the neural control processes. A correlation was found across subjects between the amplitude of the primary frequency and the maximum velocity of the fusion initialing component probably due the gain of shared neural pathways. Conclusion:  Low frequency oscillatory behavior was found in all subjects adding support that the slow, or fusion sustaining, component is mediated by a feedback control. Data have clinical implications in that dysfunction in feedback control may manifest as additional vergence error which may be reflected in the frequency spectrum

Changes in the disparity vergence main sequence after treatment of symptomatic convergence insufficiency in children

This study investigates the underlying physiological mechanisms that may lead to improved outcomes for symptomatic convergence insufficiency (CI) patients after 12 weeks of office-based vergence/accommodation therapy (OBVAT) by evaluating the change in the main sequence of vergence and saccadic eye movements. In this prospective trial, 12 participants with symptomatic CI were recruited and treated with 12 weeks of OBVAT. Outcome measures included the objective assessment of the following: peak velocity, time to peak velocity, latency, response amplitude, and clinical changes in the near point of convergence (NPC), positive fusional vergence (PFV) and symptoms via the Convergence Insufficiency Symptom Survey (CISS). Ten of the twelve participants (83%) were categorized as “successful” and two were “improved” based on pre-determined published criteria (CISS, NPC, PFV). There were statistically significant changes in peak velocity, time to peak velocity, and response amplitude for both 4° and 6° symmetrical convergence and divergence eye movements. There was a significant change in the main sequence ratio for convergence post-OBVAT compared to baseline measurements (P=0.007) but not for divergence or saccadic responses. Phasic/step vergence movements adjust the underlying neural control of convergence and are critical within a vision therapy program for CI patients

Effect of Vision Therapy on Accommodation in Myopic Chinese Children

Introduction. We evaluated the effectiveness of office-based accommodative/vergence therapy (OBAVT) with home reinforcement to improve accommodative function in myopic children with poor accommodative response. Methods. This was a prospective unmasked pilot study. 14 Chinese myopic children aged 8 to 12 years with at least 1 D of lag of accommodation were enrolled. All subjects received 12 weeks of 60-minute office-based accommodative/vergence therapy (OBAVT) with home reinforcement. Primary outcome measure was the change in monocular lag of accommodation from baseline visit to 12-week visit measured by Shinnipon open-field autorefractor. Secondary outcome measures were the changes in accommodative amplitude and monocular accommodative facility. Results. All participants completed the study. The lag of accommodation at baseline visit was 1.29 ± 0.21 D and it was reduced to 0.84 ± 0.19 D at 12-week visit. This difference (−0.46 ± 0.22 D; 95% confidence interval: −0.33 to −0.58 D) is statistically significant (p<0.0001). OBAVT also increased the amplitude and facility by 3.66 ± 3.36 D (p=0.0013; 95% confidence interval: 1.72 to 5.60 D) and 10.9 ± 4.8 cpm (p<0.0001; 95% confidence interval: 8.1 to 13.6 cpm), respectively. Conclusion. Standardized 12 weeks of OBAVT with home reinforcement is able to significantly reduce monocular lag of accommodation and increase monocular accommodative amplitude and facility. A randomized clinical trial designed to investigate the effect of vision therapy on myopia progression is warranted

Interventions for convergence insufficiency: a network meta-analysis.

BACKGROUND: Convergence insufficiency is a common binocular vision disorder in which the eyes have a strong tendency to drift outward (exophoria) with difficulty turning the eyes inward when reading or doing close work. OBJECTIVES: To assess the comparative effectiveness and relative ranking of non-surgical interventions for convergence insufficiency through a systematic review and network meta-analysis (NMA). SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, PubMed and three trials registers up to 20 September 2019. SELECTION CRITERIA: We included randomized controlled trials (RCTs) examining any form of non-surgical intervention versus placebo, no treatment, sham treatment, or other non-surgical interventions. Participants were children and adults with symptomatic convergence insufficiency. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. We performed NMAs separately for children and adults. MAIN RESULTS: We included 12 trials (six in children and six in adults) with a total of 1289 participants. Trials evaluated seven interventions: 1) office‐based vergence/accommodative therapy with home reinforcement; 2) home‐based pencil/target push‐ups; 3) home‐based computer vergence/accommodative therapy; 4) office‐based vergence/accommodative therapy alone; 5) placebo vergence/accommodative therapy or other placebo intervention; 6) prism reading glasses; and 7) placebo reading glasses. Six RCTs in the pediatric population randomized 968 participants. Of these, the Convergence Insufficiency Treatment Trial (CITT) Investigator Group completed four RCTs with 737 participants. All four CITT RCTs were rated at low risk of bias. Diagnostic criteria and outcome measures were identical or similar among these trials. The four CITT RCTs contributed data to the pediatric NMA, incorporating interventions 1, 2, 3 and 5. When treatment success was defined by a composite outcome requiring both clinical measures of convergence to be normal, and also show a pre‐specified magnitude of improvement, we found high‐certainty evidence that office‐based vergence/accommodative therapy with home reinforcement increases the chance of a successful outcome, compared with home‐based computer vergence/accommodative therapy (risk ratio (RR) 1.96, 95% confidence interval (CI) 1.32 to 2.94), home‐based pencil/target push‐ups (RR 2.86, 95% CI 1.82 to 4.35); and placebo (RR 3.04, 95% CI 2.32 to 3.98). However, there may be no evidence of any treatment difference between home‐based computer vergence/accommodative therapy and home‐based pencil/target push‐ups (RR 1.44, 95% CI 0.93 to 2.24; low‐certainty evidence), or between either of the two home‐based therapies and placebo therapy, for the outcome of treatment success. When treatment success was defined as the composite convergence and symptom success outcome, we found moderate‐certainty evidence that participants who received office‐based vergence/accommodative therapy with home reinforcement were 5.12 (95% CI 2.01 to 13.07) times more likely to achieve treatment success than those who received placebo therapy. We found low‐certainty evidence that participants who received office‐based vergence/accommodative therapy with home reinforcement might be 4.41 (95% CI 1.26 to 15.38) times more likely to achieve treatment success than those who received home‐based pencil push‐ups, and 4.65 (95% CI 1.23 to 17.54) times more likely than those who received home‐based computer vergence/accommodative therapy. There was no evidence of any treatment difference between home‐based pencil push‐ups and home‐based computer vergence/accommodative therapy, or between either of the two home‐based therapies and placebo therapy. One RCT evaluated the effectiveness of base‐in prism reading glasses in children. When base‐in prism reading glasses were compared with placebo reading glasses, investigators found no evidence of a difference in the three outcome measures of near point convergence (NPC), positive fusional vergence (PFV), or symptom scores measured by the Convergence Insufficiency Symptom Survey (CISS). Six RCTs in the adult population randomized 321 participants. We rated only one RCT at low risk of bias. Because not all studies of adults included composite success data, we could not conduct NMAs for treatment success. We thus were limited to comparing the mean difference (MD) between interventions for improving NPC, PFV, and CISS scores individually using data from three RCTs (107 participants; interventions 1, 2, 4 and 5). Compared with placebo treatment, office‐based vergence accommodative therapy was relatively more effective in improving PFV (MD 16.73, 95% CI 6.96 to 26.60), but there was no evidence of a difference for NPC or the CISS score. There was no evidence of difference for any other comparisons for any outcomes. One trial evaluated base‐in prism glasses prescribed for near‐work activities and found that the prism glasses group had fewer symptoms compared with the placebo glasses group at three months (MD ‐8.9, 95% CI ‐11.6 to ‐6.3). The trial found no evidence of a difference with this intervention in NPC or PFV. No adverse effects related to study treatments were reported for any of the included studies. Excellent adherence was reported for office‐based vergence/accommodative therapy (96.6% or higher) in two trials. Reported adherence with home‐based therapy was less consistent, with one study reporting decreasing adherence over time (weeks 7 to 12) and lower completion rates with home‐based pencil/target push‐ups. AUTHORS' CONCLUSIONS: Current research suggests that office-based vergence/accommodative therapy with home reinforcement is more effective than home-based pencil/target push-ups or home-based computer vergence/accommodative therapy for children. In adults, evidence of the effectiveness of various non-surgical interventions is less clear

A method for the isolation of human gastric mucous epithelial cells for primary cell culture: A comparison of biopsy vs surgical tissue

We have developed a method for the isolation and growth of normal human gastric mucous epithelial cells using biopsies or surgically resected tissues as the source of the cells. The attachment and growth of cells were dependent upon: (1) cell planting density, ∼50,000 cells/cm 2 ; (2) extracellular matrix (fibronectin); and (3) and the use of a porous filter. In all experiments we found better cells attachment and growth of human gastric mucous cells isolated from surgical specimens compared with those gastric mucous cells isolated from gastric biopsies. The initial cell viability (as measured by Trypan-blue) was the same in both populations of gastric mucous epithelial cells isolated from either gastric biopsies or surgical specimens. After 4–5 days in culture one could detect various amounts of mucin in all the cells using either periodic acid Schiff (PAS) staining or a specific anti-mucin antibody. A similar pattern of much straining was also found in primary cultures of guinea pig gastric mucous epithelial cells. Immunohistochemical staining for chief cells (anti-pepsinogen) or parietal cells (anti-H + /K + ATPasc) in the gastric mucous cuboidal-like epithelial cells with tight junctions, desmosomes,short microvilli, a filamentous terminal web, mucous granules, and basal lamina-like structure. We could not detect the presence of fibroblasts during the 7–9 days that the primary cells were in culture. This cell culture method will prove useful in the isolation of normal human gastric mucous epithelial cells for in vitro studies of gastric mucosal injury and repair.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43235/1/11022_2004_Article_BF00127904.pd