Home vision therapy and prism prescription in presbyopic persons with convergence insufficiency: study protocol for a randomized controlled trial.

BACKGROUND: Convergence insufficiency is a common issue in the field of binocular vision. Various treatment options have been suggested for managing this condition, but their efficacy in individuals with presbyopia remains unclear. The objective of this study is to compare the effectiveness of home-based vision therapy and prism prescription, in presbyopic patients with convergence insufficiency. METHODS/DESIGN: It is a randomized, prospective, double-blind clinical trial, with total of 150 participants randomly assigned to the three groups. The Control Group will receive a new near glasses as a conventional prescription, along with aimless and random eye movement exercises that do not have any convergence or accommodation effects. The Home Vision Therapy Group will receive new near glasses with accommodative and convergence eye exercises. The Prism Group will receive a near prismatic glasses prescribed using the Sheard's criterion. All treatments will be administered for a period of 2 months, and measurements of the modified convergence insufficiency symptoms survey (CISS), near point convergence, near phoria, and positive fusional vergence will be taken at baseline, one month later, and at the end of the treatment. DISCUSSION: We aim to identify which component - either the prism prescription or the home vision therapy - is more effective in improving binocular abilities and reducing patients' symptom scores. TRIAL REGISTRATION: ClinicalTrials.gov NCT05311917 with last update on 04/22/2023.

Office-based vergence and anti-suppression therapy for the treatment of small-to-moderate angle intermittent exotropia: A randomised clinical trial.

PURPOSE: To evaluate the short-term (1 week after completion of treatment) effect of office-based vergence and anti-suppression therapy (OBVAT) on the Office Control Score when compared to observation alone in children with small-to-moderate angle intermittent exotropia (IXT). METHODS: In this single-masked (examiner masked), two-arm, single-centre randomised clinical trial, 40 participants, 6 to <18 years of age with untreated IXT, were randomly assigned to OBVAT or observation alone. Participants assigned to therapy received 60 min of OBVAT with home reinforcement once per week for 16 weeks. Therapy included vergence, accommodation and anti-suppression techniques. The primary outcome measure was the comparison of the distance Office Control Score between the two groups at the primary outcome visit (i.e., 17-week follow-up visit). RESULTS: At the primary outcome visit, the OBVAT group (n = 20) had a significantly better distance Office Control Score (adjusted mean difference: -0.9; 95% CI: -0.2 to -1.5; p = 0.008; partial eta squared: 0.19) than the observation group (n = 16). Participants from the OBVAT group were more likely than those from the observation group to have ≥1 point of improvement at the 17-week visit (OBVAT group: 75%; Observation group: 25%; p = 0.006). CONCLUSIONS: In this randomised clinical trial of participants aged 6 to <18 years with IXT, we found that the OBVAT group had a significantly better distance Office Control Score than the observation group at the 17-week visit. This study provides the first data from a randomised clinical trial demonstrating the effectiveness of OBVAT for improving the control of IXT. Eye care practitioners should consider OBVAT as a viable, non-surgical treatment option for IXT. A full-scale randomised clinical trial investigating the long-term effectiveness of OBVAT in treating IXT is warranted.

Effects of vision therapy on near exodeviation in children with convergence insufficiency treated during the convergence insufficiency treatment trials.

PURPOSE: To report the change in the magnitude of near exodeviation in children with symptomatic convergence insufficiency successfully treated with office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial. METHODS: A total of 131 children 9-14 years of age with symptomatic convergence insufficiency classified as successfully treated with office-based vergence/accommodative therapy at the 16-week outcome visit were included. Masked examiners measured the near ocular deviation by the prism and alternate cover test at baseline, primary outcome and 1-year post-treatment. The mean change in near deviation was calculated from baseline to primary outcome, from primary outcome to 1-year post-treatment and from baseline to 1-year post-treatment. RESULTS: Of the 131 participants successfully treated with vergence/accommodative therapy, 120 completed the 1-year post-treatment visit. A significant change in near exodeviation was observed at baseline to primary outcome (2.6Δ less exo, p < 0.001, moderate effect size d = 0.61) and at baseline to 1-year post-treatment (2.0Δ less exo; p < 0.001, small effect size d = 0.45). The change from primary outcome to 1-year post-treatment (0.6Δ more exo; p = 0.06, small effect size d = 0.11) was not significant. Forty per cent (48/120) of participants had a decrease in near exodeviation >3.5∆ (expected test/retest variability) between baseline and the primary outcome examination. Of the 120 participants, one (1.0%) was esophoric at the primary outcome and was subsequently exophoric at 1-year post-treatment. Four participants (3.3%) who were orthophoric or exophoric at the primary outcome were esophoric (all ≤3∆) at the 1-year post-treatment visit. CONCLUSION: On average, the near exodeviation was smaller in size immediately after the discontinuation of vergence/accommodative therapy (2.6∆, moderate effect size) and 1 year post vergence/accommodative therapy (2.0∆, small effect size) in children with convergence insufficiency who were successfully treated; 40% had a clinically meaningful decrease in exophoria. The development of near esophoria was rare.

Comparison of simultaneous prism and cover test (SPCT) and prism and alternate cover test (PACT) measurements with final power of Press-On prism power dispensed.

PURPOSE: To investigate the association of strabismic angle obtained by simultaneous prism and cover test (SPCT) and prism alternate cover test (PACT) with the final power of Press-On prism used in adults with symptomatic strabismus. METHODS: The medical records of consecutive patients seen by a single orthoptist at an urban, tertiary care hospital over a 36-month period were reviewed retrospectively. All subjects had been prescribed Press-On prism for diplopia after evaluation with SPCT and PACT measurements at distance fixation. Prism dispensed was chosen by the patient using a trial Press-On prism set. RESULTS: A total of 244 charts were reviewed. Of these, 108 adult patients had prism dispensed, and 32 had both SPCT and PACT measurements. Mean SPCT measurement was 7Δ (median, 6Δ; range, 3Δ-14Δ); mean PACT, 13Δ (median, 11Δ; range, 8Δ-20Δ). The mean prism power dispensed was 7Δ (median, 6Δ; range, 1Δ-15Δ); this was not significantly different from mean SPCT (P = 0.35). There was a large difference (6Δ) between mean PACT measurements and mean prism dispensed (P < 0.001). At follow-up of 1 year, 21 patients (66%) remained in prism. Nine patients (4%) elected to undergo eye muscle surgery, 7 with horizontal strabismus, 6 of whom had SPCT measurements of >10Δ and PACT measurements of >15Δ. CONCLUSIONS: Press-On prism power used was more closely tied to the angle of strabismus obtained by SPCT. Overall success rate of Press-On prism was good when the prism power dispensed was close to the SPCT measurement, suggesting that it is reasonable to initiate treatment with a weaker prism, approximating the SPCT measurement, building up only if there are continuing symptoms.

Successful treatment of diplopia using prism correction combined with vision therapy/orthoptics improves health-related quality of life.

Background: To track improvement in diplopia symptoms with strabismus-specific health-related quality of life (HRQOL) questionnaire across a treatment consisting of prism correction followed by vision therapy/orthoptics when prism treatment alone has not succeeded. Methods: Forty-eight participants with diplopia and a mean age of 62.45 were asked to complete an Adult Strabismus-20 (AS-20) questionnaire and a Diplopia Questionnaire (DQ) before and after prism correction. Inclusion criteria were diplopia reported on the DQ as "sometimes", "often" or "always" at reading or straight-ahead distance. The prism correction was classified as successful if the participant reported "never" or "rarely" on the DQ for reading and straight-ahead distance; and unsuccessful if the perceived diplopia worsened or remained the same. For all participants, mean initial AS-20 scores were compared with mean post-prism correction scores, taking into account AS-20 subscales (reading and general functions, and self-perception and interaction). Participants in the failed prism treatment subgroup subsequently underwent a programme of vision therapy wearing their prism correction, the results of which were again determined by participants' responses on the AS-20 questionnaire, completed before and after the vision therapy. Results: Five of the 48 participants dropped out of the study. Prism correction was classified as successful in 22 of 43 participants (51%), and unsuccessful in 21 (49%). Those participants for whom the prism correction was classified as a success showed a statistically significant improvement (p = 0.01) in both reading and general functions. In the failed treatment subgroup, no significant change in AS-20 score was recorded for any of the domains (p = 0.1). After treatment with vision therapy/orthoptics, however, 13 of the 20 participants in the unsuccessful prism correction subgroup (one of them dropped out the study) achieved binocular vision and statistically significant improvement in reading and general functions (p = 0.01). Conclusions: Although effective prism correction of diplopia is correlated with enhanced HRQOL, prism correction alone is frequently not sufficient to achieve this objective. In these cases, vision therapy/orthoptics treatment as a coadjutant to prism correction is shown to improve HRQOL.

Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 2: non-surgical and surgical treatment options.

INTRODUCTION: Currently, there is no consensus regarding the management of intermittent exotropia (IXT), which includes both surgical and non-surgical treatment options. Nonsurgical management of IXT has been suggested and includes watchful observation, patching, overminus lenses, prism, and vision therapy/orthoptics. While a significant portion of IXT patients are treated by surgery, it is reported that there is a substantial tendency for reoperation or recurrence of IXT. This paper provides a comprehensive review of non-surgical and surgical treatment options for the IXT. METHODS: Search strategies involving combination of keywords including intermittent exotropia, divergence excess, basic exotropia, refractive error, glasses, spectacles, natural history, untreated, observe, occlusion, patch, overminus, overcorrecting minus, prism, vision therapy, orthoptic, anti-suppression, fusion exercise, and surgery were used in Medline. All English articles from 01/01/1900 to 01/09/2020 were reviewed. The reference list of the identified articles was also checked for additional relevant articles. Studies focused on animal models or strabismus associated with neurologic disorders or injury were excluded. The following filters were used for surgical management due to the abundance of reports: full text, randomized controlled trial, review, in the last 5 years. RESULTS: Appropriate optical correction of refractive error is generally the starting point for all management approaches, but there is a lack of randomized clinical trial data regarding this treatment modality. Randomized clinical trial data indicate that both observation and occlusion are reasonable management options for children 3-10 years old, and there were insufficient data to recommend occlusion for children 12-35 months old. While overminus lenses were found to improve the control of IXT when assessed wearing overminus spectacles, this improvement did not persist after the treatment ended. The result of the only randomized clinical trial on the effectiveness of base-in prism indicated that this treatment is no more effective than nonprism spectacles for improving control. A recent randomized clinical trial showed that vision therapy/orthoptics is effective in improving the control of IXT when compared to observation alone. Surgery was found to alter a number of clinical characteristics of IXT, including reducing the distance and near angle of deviation, reducing photophobia, improving health-related quality of life, stereopsis, and the Newcastle Control Score. However, there are no randomized clinical trial data comparing surgery with a control group such as placebo or a no treatment observation group. DISCUSSION: Rigorously designed clinical trials to investigate the effectiveness of non-surgical and surgical treatments for intermittent exotropia are needed.

Terapia visual: ¿En qué consiste y cuándo indicarla? / Vision therapy: what is it and when should it be indicated?

RESUMEN La terapia visual es un programa de ejercicios visuales personalizados, donde se realiza una estimulación neurofisiológica que nos permite desarrollar, mejorar e integrar las capacidades visuales. Esta serie de actividades específicas están pensadas para corregir problemas de visión. La terapia visual tiene como fin obtener una visión simple, nítida, confortable y eficaz. En la sociedad actual de la información y del conocimiento, donde hay un uso excesivo de la visión de cerca que provoca síntomas oculares como consecuencia del estrés visual, esta es una opción terapéutica a tener presente en sus diferentes variantes(AU)

ABSTRACT Vision therapy is a program of personalized visual exercises by which neurophysiological stimulation is provided to develop, improve and integrate visual capacities. It consists of a series of specific activities designed to correct vision problems. The purpose of vision therapy is to obtain single, neat, comfortable and efficient vision. In today's information and knowledge society, characterized by excessive use of near vision, leading to ocular symptoms resulting from visual stress, this is a therapy option to be taken into account in its various forms(AU)

Genetic aspects of strabismus

Purpose: To evaluate the genetic aspects of strabismus. Methods: Ophthalmic and orthoptic evaluations were performed prospectively on 110 strabismic probands and 478 relatives. We used 3 different criteria in the diagnosis of strabismus: primary diagnósis (dxl) defined as any manifest horizontal or vertical deviation, a secondary diagnosis (dx2) including esophoria (>7 prism diopters) or exophoria (>9 prism diopters), and a tertiary diagnosis (dx3) including abnormal fusional amplitudes, accommodative convergence/accommodation (AC/A) ratio, andor stereopsis; monofixation syndrome; 4 prism diopters base out; and/or abnormal Maddox test responses. Analyses were carried out within mating types. Results: Hypotheses of autosomal dominant or recessive inheritance with no sporadics were rejected. Based on the dx 1, 25 percent of the families had more than one individual affected and there was vertical transmission in 13 percent; adding dx2 there were 36 percent of the families with more than one affected and 21 percent had vertical transmission; and adding dx3, there were 73 percent with more than one affected and 51 percent with vertical transmission. Conclusions: There is evidence for a pattern consistent with an autosomal dominant form of strabismus in most families.

Prism therapy for adult onset strabismus

The Fresnel press-on-prism has dramatically changed the type of patient seen in our Orthoptic Department. More and more orthoptist in the USA are seeing more and more adult patients and are using more and more prisms for the annoying symptoms of diplopia

Manejo ortóptico del estrabismo precoz / Orthoptic management of early strabismus

Se hace un resumen del tratamiento ortóptico del estrabismo congénito en niños desde los 6 meses de edad. Se muestra las distintas formas de oclusión. La revisión de historias clínicas demuestra que las cirugías tempranas no garantizan al paciente visión binocular ni estereopsis. El seguimiento ortóptico postquirúrgico es ideal. Con su variedad de formas de tratamiento ayuda a complementar el éxito de la cirugía y mantener en lo posible una buena agudeza visual en ambos ojos