Assessing the role of visual dysfunctions in the association between visual symptomatology and the use of digital devices / Evaluación del papel de las disfunciones visuales en la asociación entre la sintomatología visual y el uso de dispositivos digitales

Purpose: To evaluate the association between visual symptoms and use of digital devices considering the presence of visual dysfunctions. Methods: An optometric examination was conducted in a clinical sample of 346 patients to diagnose any type of visual anomaly. Visual symptoms were collected using the validated SQVD questionnaire. A threshold of 6 hours per day was used to quantify the effects of digital device usage and patients were divided into two groups: under and above of 35 years old. A multivariate logistic regression was employed to investigate the association between digital device use and symptoms, with visual dysfunctions considered as a confounding variable. Crude and the adjusted odds ratio (OR) were calculated for each variable. Results: 57.02 % of the subjects reported visual symptoms, and 65.02% exhibited some form of visual dysfunction. For patients under 35 years old, an association was found between having visual symptoms and digital device use (OR = 2.10, p = 0.01). However, after adjusting for visual dysfunctions, this association disappeared (OR = 1.44, p = 0.27) and the association was instead between symptoms and refractive dysfunction (OR = 6.52, p < 0.001), accommodative (OR = 10.47, p < 0.001), binocular (OR = 6.68, p < 0.001) and accommodative plus binocular dysfunctions (OR = 46.84, p < 0.001). Among patients over 35 years old, no association was found between symptoms and the use of digital devices (OR = 1.27, p = 0.49) but there was an association between symptoms and refractive dysfunction (OR = 3.54, p = 0.001). Conclusions: Visual symptoms are not dependent on the duration of digital device use but rather on the presence of any type of visual dysfunction: refractive, accommodative and/or binocular one, which should be diagnosed.(AU)

Efficacy of optometric phototherapy: a systematic review

PurposeTo analyse the scientific evidence about the efficacy of Syntonic phototherapy for producing changes in visual function.Material and methodsA systematic review was performed to obtain studies on the effects of Syntonic phototherapy on vision. A search in health science databases (Medline, Scopus, Web of Science and PsycINFO) for studies published between 1980 and 2022 was conducted in accordance with the principles of Cochrane approach. The search identified 197 articles. Only clinical studies which used the Syntonic phototherapy as a vision therapy for any visual condition were included. Clinical cases and case series were excluded. Following the inclusion criteria, 8 clinical studies met inclusion, 5 of them being pseudo-experimental studies with an equivalent control group and 3 pre-post pseudo-experimental studies. GRADE tool was used to assess the certainty of the evidence of the studies. The GRADE evidence profile for the studies through the Soft table was made to analyse data.ResultsThe studies analysed seven outcomes: visual symptoms, functional visual fields, visual acuity, contrast sensitivity, deviation (phoria/tropia), stereopsis and reading abilities. Finding table about results (Soft Table) showed that for all outcomes reviewed, all studies yielded very low certainty of evidence. Results revealed a lack of scientific evidence of the efficacy of Syntonic optometric phototherapy to produce changes in the visual function.ConclusionThis systematic review found no consistent evidence for the efficacy of Syntonic phototherapy to cause changes in visual function. There is no scientific evidence to support its clinical use for treating any type of visual anomalies. (AU)

Assessing the role of visual dysfunctions in the association between visual symptomatology and the use of digital devices.

PURPOSE: To evaluate the association between visual symptoms and use of digital devices considering the presence of visual dysfunctions. METHODS: An optometric examination was conducted in a clinical sample of 346 patients to diagnose any type of visual anomaly. Visual symptoms were collected using the validated SQVD questionnaire. A threshold of 6 hours per day was used to quantify the effects of digital device usage and patients were divided into two groups: under and above of 35 years old. A multivariate logistic regression was employed to investigate the association between digital device use and symptoms, with visual dysfunctions considered as a confounding variable. Crude and the adjusted odds ratio (OR) were calculated for each variable. RESULTS: 57.02 % of the subjects reported visual symptoms, and 65.02% exhibited some form of visual dysfunction. For patients under 35 years old, an association was found between having visual symptoms and digital device use (OR = 2.10, p = 0.01). However, after adjusting for visual dysfunctions, this association disappeared (OR = 1.44, p = 0.27) and the association was instead between symptoms and refractive dysfunction (OR = 6.52, p < 0.001), accommodative (OR = 10.47, p < 0.001), binocular (OR = 6.68, p < 0.001) and accommodative plus binocular dysfunctions (OR = 46.84, p < 0.001). Among patients over 35 years old, no association was found between symptoms and the use of digital devices (OR = 1.27, p = 0.49) but there was an association between symptoms and refractive dysfunction (OR = 3.54, p = 0.001). CONCLUSIONS: Visual symptoms are not dependent on the duration of digital device use but rather on the presence of any type of visual dysfunction: refractive, accommodative and/or binocular one, which should be diagnosed.

Efficacy of optometric phototherapy: a systematic review.

PURPOSE: To analyse the scientific evidence about the efficacy of Syntonic phototherapy for producing changes in visual function. MATERIAL AND METHODS: A systematic review was performed to obtain studies on the effects of Syntonic phototherapy on vision. A search in health science databases (Medline, Scopus, Web of Science and PsycINFO) for studies published between 1980 and 2022 was conducted in accordance with the principles of Cochrane approach. The search identified 197 articles. Only clinical studies which used the Syntonic phototherapy as a vision therapy for any visual condition were included. Clinical cases and case series were excluded. Following the inclusion criteria, 8 clinical studies met inclusion, 5 of them being pseudo-experimental studies with an equivalent control group and 3 pre-post pseudo-experimental studies. GRADE tool was used to assess the certainty of the evidence of the studies. The GRADE evidence profile for the studies through the Soft table was made to analyse data. RESULTS: The studies analysed seven outcomes: visual symptoms, functional visual fields, visual acuity, contrast sensitivity, deviation (phoria/tropia), stereopsis and reading abilities. Finding table about results (Soft Table) showed that for all outcomes reviewed, all studies yielded very low certainty of evidence. Results revealed a lack of scientific evidence of the efficacy of Syntonic optometric phototherapy to produce changes in the visual function. CONCLUSION: This systematic review found no consistent evidence for the efficacy of Syntonic phototherapy to cause changes in visual function. There is no scientific evidence to support its clinical use for treating any type of visual anomalies.

Validation of the Symptom Questionnaire for Visual Dysfunctions (SQVD): A Questionnaire to Evaluate Symptoms of any Type of Visual Dysfunctions.

PURPOSE: To assess psychometric properties of the Symptom Questionnaire for Visual Dysfunctions (SQVD) questionnaire, including accuracy, validity, and reliability, in a clinical sample of patients having any type of visual dysfunction. METHODS: A clinical sample of 306 patients self-administered the SQVD. Rasch analysis was performed to analyze the functionality of the response categories, fit statistics, differential item functioning (DIF), person and item reliability, targeting, local dependency, unidimensionality, and transformation table. Accuracy was assessed by means of receiver operating characteristic (ROC) curves, using symptoms reported in each patient's clinical record as the gold standard for classifying patients with and without symptoms. The concurrent validity, known group validity, and test-retest reliability (repeatability, using the intraclass correlation coefficient [ICC]) were also examined. RESULTS: SQVD showed orderly category responses. The 14 items fit the Rasch model without significant DIF for gender, presbyopia, and dysfunctions. Person and item reliabilities were 0.81 and 0.85, respectively. Targeting was -1.49 logits. Yen's Q3 statistic showed no local dependency. SQVD was unidimensional (first contrast of the residual = 1.852 eigenvalue with a variance explained by measures of 52.23%). The area under the ROC curve was 0.836 (95% confidence interval [CI], 0.792-0.879) with a cutoff of ≥6 showing good accuracy (sensitivity = 0.759; specificity = 0.783). SQVD showed good concurrent and known group validity and high repeatability (ICC, 0.857; 95% CI, 0.710-0.933) when administered twice 1 week apart. CONCLUSIONS: SQVD has shown good psychometric properties. It can be considered an accurate, valid, and reliable questionnaire to detect visual symptoms related to any type of refractive, accommodative, and binocular dysfunction. TRANSLATIONAL RELEVANCE: SQVD may be used for diagnostic purposes, as it can accurately detect symptoms related to any sort of visual dysfunction. It may also be useful to monitor the treatment outcomes of these conditions.

Rasch analysis for development and reduction of Symptom Questionnaire for Visual Dysfunctions (SQVD).

To develop the Symptom Questionnaire for Visual Dysfunctions (SQVD) and to perform a psychometric analysis using Rasch method to obtain an instrument which allows to detect the presence and frequency of visual symptoms related to any visual dysfunction. A pilot version of 33 items was carried out on a sample of 125 patients from an optometric clinic. Rasch model (using Andrich Rating Scale Model) was applied to investigate the category probability curves and Andrich thresholds, infit and outfit mean square, local dependency using Yen's Q3 statistic, Differential item functioning (DIF) for gender and presbyopia, person and item reliability, unidimensionality, targeting and ordinal to interval conversion table. Category probability curves suggested to collapse a response category. Rasch analysis reduced the questionnaire from 33 to 14 items. The final SQVD showed that 14 items fit to the model without local dependency and no significant DIF for gender and presbyopia. Person reliability was satisfactory (0.81). The first contrast of the residual was 1.908 eigenvalue, showing unidimensionality and targeting was - 1.59 logits. In general, the SQVD is a well-structured tool which shows that data adequately fit the Rasch model, with adequate psychometric properties, making it a reliable and valid instrument to measure visual symptoms.

Delphi methodology for symptomatology associated with visual dysfunctions.

To analyse what eyecare clinicians think about which symptoms are associated with refractive, accommodative and binocular dysfunctions, and which of them should be used in a questionnaire of visual symptomatology. A Delphi method was developed, using a coordinating group and a group of experts, and the process was conducted in three rounds. In the first round we compiled a list of 34 symptoms from the scientific literature and additional 10 suggested by the experts. These symptoms were categorized by each expert to the associated visual anomalies and working distance. In the second round, the relationship between each symptom and visual dysfunctions was analysed using a numeric scale. In the third round, the appearance or absence of the 44 symptoms in a questionnaire was assessed. Symptoms most frequently assigned by the experts to visual anomalies were related to near vision. Symptoms of blurred vision, difficulty focusing from one distance to another and close one eye obtained the highest mean score for refractive, accommodative and binocular disorders respectively. The experts were in agreement for 15 symptoms and in disagreement for 5 symptoms that should appear in a questionnaire. Delphi method has been used to identify the symptoms related to visual dysfunctions according to eyecare professionals and has allowed to arrive at appropriate symptoms to be asked for in a visual symptomatology questionnaire.

Measuring the heterophoria: Agreement between two methods in non-presbyopic and presbyopic patients / Medición de la heteroforia: concordancia entre dos métodos en pacientes sin y con presbicia

Purpose: To establish whether the cover test and von Graefe methods are interchangeable in a non-presbyopic and presbyopic population. Methods: We performed a prospective study on a sample of 127 non-presbyopic subjects between 20 and 45 years old and 56 presbyopic between 40 and 78 years old. Distance and near vision phoria were measured using the von Graefe method (VG) and cover test (CT). We analyzed the significant differences between methods, their correlation and the agreement between them using the Bland and Altman method. Results: For distance vision, heterophoria values for non-presbyopic subjects were -0.61 ± 1.86Δ with CT and -0.88 ± 2.37Δ with VG, and for presbyopic subjects were -0.56 ± 1.64Δ with CT and -0.85 ± 1.94Δ with VG. For near vision, CT yielded -3.02 ± 3.97Δ, while VG achieved -3.49 ± 4.70Δ in non-presbyopic subjects. For presbyopic subjects these values were -6.05 ± 4.38Δ with CT and -6.29 ± 4.19Δ with VG, respectively. Statistically significant differences between the two methods were observed for all groups analyzed (p<0.05), except for near vision in presbyopic subjects (p > 0.05). Coefficient of agreement for non-presbyopic was ±2.97Δ for distance vision and ±6.74Δ at near. For presbyopic patients, this coefficient was ±1.59Δ for distance and ±1.86Δ for near vision. Conclusion: Cover test and von Graefe methods have a high level of agreement for both distance and near vision when considering presbyopic subjects. For non-presbyopic patients, the level of agreement is very low. Both methods for measuring heterophoria can only be considered interchangeable for presbyopic patients. For clinical purposes, this implies that any method can be used for measuring heterophoria in presbyopic patients

Objetivo: Establecer si el "cover test" y el método de von Graefe son intercambiables en la población sin y con presbicia. Métodos: Realizamos un estudio prospectivo en una muestra de 127 sujetos sin presbicia de edades comprendidas entre 20 y 45 años, y 56 sujetos con presbicia de entre 40 y 78 años de edad. Se midieron la foria de cerca y lejos utilizando el método de von Graefe (VG) y el cover test (CT). Analizamos las diferencias significativas entre ambos métodos, así como la correlación y concordancia entre ambos utilizando el método de Bland & Altman. Resultados: Para la visión de lejos, los valores de heteroforia para los sujetos sin presbicia fueron de -0,61 ± 1,86Δ con CT y de -0,88 ± 2,37Δ con VG y, para los sujetos con presbicia, de -0,56 ± 1,64Δ con CT y de -0,85 ± 1,94Δ con VG. Para la visión de cerca, los valores de CT fueron de -3,02 ± 3,97Δ, mientras que los valores de VG fueron de -3,49 ± 4,7Δ en sujetos sin presbicia. Para los sujetos con presbicia, los valores fóricos fueron de -6,05 ± 4,38Δ con CT y de -6,29±4,19Δ con VG. Se observaron diferencias estadísticamente significativas entre los dos métodos para todos los grupos analizados (p < 0,05), excepto para la visión de cerca en sujetos con presbicia (p > 0,05). El coeficiente de concordancia para los sujetos sin presbicia fue de ± 2,97Δ para la visión de lejos, y de ± 6,74Δ para la de cerca. Para los pacientes con presbicia, dicho coeficiente fue de ± 1,59Δ para la visión de lejos, y de ± 1,86Δ para la de cerca. Conclusión: El "cover test" y el método de von Graefe tienen un alto nivel de concordancia para la visión de lejos y cerca, en relación a los sujetos con presbicia. Para sujetos sin presbicia, el nivel de concordancia es muy bajo. Ambos métodos de medición pueden intercambiarse para medir la heteroforia únicamente en pacientes con presbicia. A efectos clínicos, esto implica que puede utilizarse cualquiera de los dos métodos para medir la heteroforia en pacientes con presbicia

Measuring the heterophoria: Agreement between two methods in non-presbyopic and presbyopic patients.

PURPOSE: To establish whether the cover test and von Graefe methods are interchangeable in a non-presbyopic and presbyopic population. METHODS: We performed a prospective study on a sample of 127 non-presbyopic subjects between 20 and 45 years old and 56 presbyopic between 40 and 78 years old. Distance and near vision phoria were measured using the von Graefe method (VG) and cover test (CT). We analyzed the significant differences between methods, their correlation and the agreement between them using the Bland and Altman method. RESULTS: For distance vision, heterophoria values for non-presbyopic subjects were -0.61±1.86Δ with CT and -0.88±2.37Δ with VG, and for presbyopic subjects were -0.56±1.64Δ with CT and -0.85±1.94Δ with VG. For near vision, CT yielded -3.02±3.97Δ, while VG achieved -3.49±4.70Δ in non-presbyopic subjects. For presbyopic subjects these values were -6.05±4.38Δ with CT and -6.29±4.19Δ with VG, respectively. Statistically significant differences between the two methods were observed for all groups analyzed (p<0.05), except for near vision in presbyopic subjects (p>0.05). Coefficient of agreement for non-presbyopic was ±2.97Δ for distance vision and ±6.74Δ at near. For presbyopic patients, this coefficient was ±1.59Δ for distance and ±1.86Δ for near vision. CONCLUSION: Cover test and von Graefe methods have a high level of agreement for both distance and near vision when considering presbyopic subjects. For non-presbyopic patients, the level of agreement is very low. Both methods for measuring heterophoria can only be considered interchangeable for presbyopic patients. For clinical purposes, this implies that any method can be used for measuring heterophoria in presbyopic patients.

Accommodative and binocular dysfunctions: prevalence in a randomised sample of university students.

BACKGROUND: The aim was to analyse the prevalence of symptomatic accommodative and non-strabismic binocular dysfunctions in a randomised population of university subjects. METHODS: A cross-sectional study was conducted with a randomised sample of 175 university students aged between 18 and 35 years. All subjects were given a visual examination in which their symptoms were recorded, as well as performing objective and subjective refractive examinations and accommodative and binocular tests. Each subject was tested for the presence of uncorrected refractive error. Accommodative dysfunctions (AD) and binocular dysfunctions (BD) were diagnosed according to the number of clinical signs associated with each disorder, considering the signs that could be associated with each dysfunction as fundamental or complementary. An accommodative or binocular dysfunction was diagnosed when the subjects met two conditions: presenting with any kind of visual symptom in their clinical history and presenting the fundamental sign associated with each dysfunction as well as two or more complementary signs. Those subjects who presented with only an uncorrected refractive error were considered within the group called refractive dysfunction (RD). RESULTS: The overall prevalence of accommodative and/or binocular dysfunctions was 13.15 per cent and for refractive dysfunction it was 45.14 per cent. Accommodative dysfunctions were present in 2.29 per cent of the population, binocular dysfunctions were observed in eight per cent and accommodative dysfunctions together were found in 2.86 per cent of the university students. Within the accommodative and binocular disorders, the most prevalent dysfunctions were convergence insufficiency, with a prevalence of 3.43 per cent and convergence excess and accommodation excess, both with a prevalence of 2.29 per cent. CONCLUSION: Binocular dysfunctions were more prevalent than accommodative dysfunctions or accommodative and binocular dysfunctions together in a randomised population of university students.

Characterization of Visual Symptomatology Associated with Refractive, Accommodative, and Binocular Anomalies.

Purpose. To characterize the symptomatology of refractive, accommodative, and nonstrabismic binocular dysfunctions and to assess the association between dysfunctions and symptoms. Methods. 175 randomised university students were examined. Subjects were given a subjective visual examination with accommodative and binocular tests, evaluating their symptomatology. Accommodative and binocular dysfunctions (AD, BD) were diagnosed according to the number of existing clinical signs: suspect AD or BD (one fundamental clinical sign), high suspect (one fundamental + 1 complementary clinical sign), and definite (one fundamental + 2 or more complementary clinical signs). A logistic regression was conducted in order to determine whether there was an association between dysfunctions and symptoms. Results. 78 subjects (44.6%) reported any kind of symptoms which were grouped into 18 categories, with "visual fatigue" being the most frequent (20% of the overall complaints). Logistic regression adjusted by the presence of an uncorrected refractive error showed no association between any grade of AD and symptoms. Subjects with BD had more likelihood of having symptoms than without dysfunction group (OR = 3.35), being greater when only definite BD were considered (OR = 8.79). Conclusions. An uncorrected refractive error is a confusion factor when considering AD symptomatology. For BD, the more the number of clinical signs used the greater the likelihood suffering symptoms.

Symptomatology associated with accommodative and binocular vision anomalies.

PURPOSE: To determine the symptoms associated with accommodative and non-strabismic binocular dysfunctions and to assess the methods used to obtain the subjects' symptoms. METHODS: We conducted a scoping review of articles published between 1988 and 2012 that analysed any aspect of the symptomatology associated with accommodative and non-strabismic binocular dysfunctions. The literature search was performed in Medline (PubMed), CINAHL, PsycINFO and FRANCIS. A total of 657 articles were identified, and 56 met the inclusion criteria. RESULTS: We found 267 different ways of naming the symptoms related to these anomalies, which we grouped into 34 symptom categories. Of the 56 studies, 35 employed questionnaires and 21 obtained the symptoms from clinical histories. We found 11 questionnaires, of which only 3 had been validated: the convergence insufficiency symptom survey (CISS V-15) and CIRS parent version, both specific for convergence insufficiency, and the Conlon survey, developed for visual anomalies in general. The most widely used questionnaire (21 studies) was the CISS V-15. Of the 34 categories of symptoms, the most frequently mentioned were: headache, blurred vision, diplopia, visual fatigue, and movement or flicker of words at near vision, which were fundamentally related to near vision and binocular anomalies. CONCLUSIONS: There is a wide disparity of symptoms related to accommodative and binocular dysfunctions in the scientific literature, most of which are associated with near vision and binocular dysfunctions. The only psychometrically validated questionnaires that we found (n=3) were related to convergence insufficiency and to visual dysfunctions in general and there no specific questionnaires for other anomalies.

Is there any evidence for the validity of diagnostic criteria used for accommodative and nonstrabismic binocular dysfunctions?

PURPOSE: To analyze the diagnostic criteria used in the scientific literature published in the past 25 years for accommodative and nonstrabismic binocular dysfunctions and to explore if the epidemiological analysis of diagnostic validity has been used to propose which clinical criteria should be used for diagnostic purposes. METHODS: We carried out a systematic review of papers on accommodative and non-strabic binocular disorders published from 1986 to 2012 analysing the MEDLINE, CINAHL, PsycINFO and FRANCIS databases. We admitted original articles about diagnosis of these anomalies in any population. We identified 839 articles and 12 studies were included. The quality of included articles was assessed using the QUADAS-2 tool. RESULTS: The review shows a wide range of clinical signs and cut-off points between authors. Only 3 studies (regarding accommodative anomalies) assessed diagnostic accuracy of clinical signs. Their results suggest using the accommodative amplitude and monocular accommodative facility for diagnosing accommodative insufficiency and a high positive relative accommodation for accommodative excess. The remaining 9 articles did not analyze diagnostic accuracy, assessing a diagnosis with the criteria the authors considered. We also found differences between studies in the way of considering patients' symptomatology. 3 studies of 12 analyzed, performed a validation of a symptom survey used for convergence insufficiency. CONCLUSIONS: Scientific literature reveals differences between authors according to diagnostic criteria for accommodative and nonstrabismic binocular dysfunctions. Diagnostic accuracy studies show that there is only certain evidence for accommodative conditions. For binocular anomalies there is only evidence about a validated questionnaire for convergence insufficiency with no data of diagnostic accuracy.

Diagnostic validity of clinical signs associated with a large exophoria at near.

Purpose. To analyze the diagnostic validity of accommodative and binocular tests in a sample of patients with a large near exophoria with moderate to severe symptoms. Methods. Two groups of patients between 19 and 35 years were recruited from a university clinic: 33 subjects with large exophoria at near vision and moderate or high visual discomfort and 33 patients with normal heterophoria and low visual discomfort. Visual discomfort was defined using the Conlon survey. A refractive exam and an exhaustive evaluation of accommodation and vergence were assessed. Diagnostic validity by means of receiver operator characteristic (ROC) curves, sensitivity (S), specificity (Sp), and positive and negative likelihood ratios (LR+, LR-) were assessed. This analysis was also carried out considering multiple tests as serial testing strategy. Results. ROC analysis showed the best diagnostic accuracy for receded near point of convergence (NPC) recovery (area = 0.929) and binocular accommodative facility (BAF) (area = 0.886). Using the cut-offs obtained with ROC analysis, the best diagnostic validity was obtained for the combination of NPC recovery and BAF (S = 0.77, Sp = 1, LR+ = value tending to infinity, LR- = 0.23) and the combination of NPC break and recovery with BAF (S = 0.73, Sp = 1, LR+ = tending to infinity, LR- = 0.27). Conclusions. NPC and BAF tests were the tests with the best diagnostic accuracy for subjects with large near exophoria and moderate to severe symptoms.

Treatment of accommodative and nonstrabismic binocular dysfunctions: a systematic review.

BACKGROUND: The aim of this study was to analyze the scientific evidence available on the nonsurgical treatment of accommodative and nonstrabismic binocular dysfunctions, identifying the types of treatment used and their efficacy. METHODS: A systematic review of reports published from 1986 to 2007 was completed using several health science databases: FRANCIS, Medline, Cinahl, and PsycINFO. Those papers that analyzed the treatment of accommodative and nonstrabismic binocular anomalies were included. RESULTS: Of the 565 articles identified, 16 met the inclusion criteria. Only 3 were clinical trials. All analyzed treatment of convergence insufficiency. Results of clinical trials support the conclusion that vision therapy improves symptoms and signs for convergence insufficiency. Further, the evidence indicates that pencil push-up treatment is not as effective as vision therapy and that prism glasses are no more effective than placebo glasses. For the other nonstrabismic binocular conditions and accommodative disorders, there is a lack of published randomized, clinical trials that support the evidence for the efficacy of each treatment. CONCLUSION: Scientific evidence exists for the efficacy of vision therapy for convergence insufficiency. Insufficient scientific evidence exists on the best therapeutic options for treatment of the other nonstrabismic binocular anomalies and accommodative disorders.