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Problemstellung: Diese Arbeit beschäftigt sich mit dem Fallbeispiel einer jungen Patientin, bei welcher vor mehr als zehn Jahren ein Verdacht auf einen Akkommodationsspasmus und Pseudomyopie gestellt wurde. Später zeigt sich, dass es sich um eine Exophorie, die über die akkommodative Konvergenz kompensiert wird, handelt. Es folgen eine Analyse sowie Diskussion der angewendeten Untersuchungs- und Behandlungsmethoden. Methoden: In diesem Kapitel erfolgt die genaue Beschreibung der Untersuchungsmethoden, die bei der Patientin zur Anwendung gekommen sind. Darunter fallen sowohl die orthoptischen, auch der ausschlaggebende 4-Prismen-Basis-Innen-Test, als auch ophthalmologischen Untersuchungen. Ergebnisse: In diesem Abschnitt werden die Ergebnisse der im Patientenfall erhobenen Untersuchungen beschrieben. Des Weiteren wird der Krankheitsverlauf bis zur passenden Therapie dargestellt. Nachdem der 4-Prismen-Basis-Innen-Test positiv ausfiel, wurde eine Prismenbrille verordnet. Diskussion/Schlussfolgerung: Es wird die Literatur mit dem Patientenfall verglichen und mithilfe dessen der Verdacht auf das Krankheitsbild Exophorie, die durch die akkommodative Konvergenz kompensiert wird, bestätigt. Im Rahmen dessen ist die Differentialdiagnose „Akkommodationsspasmus“ ebenfalls Thema dieses Kapitels. Introduction: This paper analyzes the case of a young patient who was suspected of having an accommodative spasm and pseudomyopia more than ten years ago. However, the patient seems to have exophoria which is compensated by accommodative convergence. An analysis and discussion of the performed examination and treatment methods follows. Methods: In this chapter, a detailed description of the methods used during the examination is given. This includes orthoptic as well as ophthalmological examinations. In addition to these, the decisive 4-prism base-inside test was done also. Results: This chapter describes the results of the examinations carried out in the patient's case. Furthermore, the course of the disease up to the appropriate therapy is presented. After the 4-prism base-inside test was positive, prism glasses were prescribed. Discussion/conclusion: The literature is compared with the patient's case and a suspicion of exophoria compensated by accommodative convergence is confirmed. The differential diagnosis “accommodation spasm” is also part of this chapter.

Purpose: To assess if high accommodative convergence/accommodation (AC/A) ratio impacts surgical outcomes in children with esotropia (ET), and evaluate the appropriate target angle in surgical dosing in the presence of high AC/A ratio. Methods: A retrospective chart review identified patients who underwent primary bilateral medial rectus (BMR) recessions for ET. Patients were excluded if follow-up was ≤2 months. Basic demographic information, visual acuity, stereopsis, alignment, and target angle for surgery were collected. High AC/A was defined as ≥10 prism diopter (Δ) deviation at near compared to distance. Outcome parameters were near and distance deviations ≤10Δ within orthophoria, and/or stereopsis postoperatively. Yates' continuity correction, unpaired t-test, regression analysis, and one-way ANOVA were used. Results: We identified 103 patients, 23 with high AC/A and 80 with normal AC/A, preoperatively. Mean age was 4.0 ± 2.5 years. Surgical success measured by postoperative alignment was 48% and 45% in the high AC/A and normal AC/A groups, respectively (P = 1.0). There was a statistically significant difference in preoperative near deviation between high AC/A and normal AC/A groups (P = 0.0015); however, there was no significant difference in preoperative distance deviation (P = 0.061). In addition, there was not a significant difference in preoperative or postoperative stereopsis between high AC/A and normal AC/A groups (P = 0.88 and P = 0.44, respectively). There was a significant difference in the normal AC/A and high AC/A groups when target angle was directed toward preoperative near deviation as determined by one-way ANOVA (F = 170.88, P < 0.0001 and F = 14.61, P = 0.0010, respectively). Conclusion: In the setting of ET treated with BMR recession, the presence of high AC/A does not affect surgical success as measured by alignment and stereopsis. In addition, when high AC/A is present, surgical dosing with a target angle toward near deviation was found to yield the best surgical outcomes in our patient population.

Supplemental digital content is available in the text., SIGNIFICANCE With reported population differences in parameters of nonstrabismic binocular vision, the present study investigated and reports normative data among a sample of African children. PURPOSE This study aimed to determine expected binocular visual function data among schoolchildren in the Central Region of Ghana. METHODS The study used a prospective cross-sectional design and used a multistage cluster sampling approach. Eligible normal participants selected through the administration of Convergence Insufficiency Symptom Survey questionnaire (score

Abnormal accommodative convergence per diopter of accommodative response (AC/A ratio) ratio is an important factor leading to myopia. This study aimed to examine the effect of refractive correction on the gradient of AC/A ratio with low-to-moderate myopia in children and adolescents. Children and adolescents aged 8-18 years, with low and moderate myopia, were divided into groups of myopia with no refractive correction and myopic continuous refractive correction of more than half a year. Then, in accordance with the myopia gradient, they were further divided into 0.00 to - 1.50, - 1.75 to - 3.00, - 3.25 to - 4.50, and - 4.75 to - 6.00 groups. Results showed that the AC/A ratio of the myopic group without refractive correction history was significantly higher than that with refractive correction history for more than half a year. The AC/A ratio increased with the deepening of myopia in the group without refractive history of myopia. However, it decreased significantly in the group with refractive history of myopia for more than half a year. Therefore, the AC/A ratio is related to the degree of uncorrected myopia, and it increases with the degree of uncorrected myopia.

Purpose: Accommodative-convergence mechanism failure could occur in non presbyopic HIV- sero positive patients on Highly Active Anti-Retroviral Therapy (HAART). This could be due to either direct neuronal infection by HIV, pathologic changes of the lens or the ciliary body or adverse effects of some individual drugs constituting the HAART regimen on the cranial nerves which play vital roles in the mechanism of accommodation and convergence. Case report: This is a case report of an accommodative- convergence mechanism failure in HIV positive non presbyopic 32-year-old male patient that was on HAART for more than five years. He presented with distance visual acuity (VA) of OD: 6/9 +2, OS: 6/9, and near visual acuity (NVA) of N24 both eyes, 3Δ esophoria at distance and 4Δ esophoria at near. Amplitude of accommodation (AA) was 3.50D and accommodative convergence/accommodation (AC/A) ratio was 6/1. Following comprehensive evaluation, his refractive correction was OD: Plano/-0.50DC X 180 6/5 and OS: Plano/-0.50DC X 90 6/5 at distance with near addition (Add) 2.50D N5. This was prescribed for regular wear in form of D-Top bifocal lens. Conclusion: These findings showed that HIV sero-positive adults on HAART could develop accommodativeconvergence mechanism failure, which may be characterized by low amplitude of accommodation, receded near point of convergence and high non presbyopic reading addition. These conditions may be under-recognized and need for reading addition of a non presbyopic age is often overlooked. Key Words: Accommodative-Convergence, HIV, Lateral Phoria, Refractive error.

Purpose Post-rotatory nystagmus has been used to detect autism spectrum disorders in clinical settings. Although previous studies have focused on eye movements, they did not evaluate the change in ocular refraction during post-rotatory nystagmus. This study aimed to evaluate the changes in ocular refraction during post-rotatory nystagmus in healthy individuals. Methods A total of 34 healthy volunteers (mean age ± standard deviation, 20.9 ± 0.6 years) participated in this study. The ocular refraction during post-rotatory nystagmus was measured using MR-6000 (Tomey Inc.) on quick mode with a sampling rate of 30 Hz under noncycloplegic and cycloplegic conditions. The amplitude of post-rotatory nystagmus was calculated on the basis of the anterior eye images, while the ocular refraction measurements were simultaneously recorded. The accommodative convergence per accommodation ratio was calculated using the heterophoria method. Video oculography was performed to measure the angle of convergence during post-rotatory nystagmus. Results The changes in ocular refraction during post-rotatory nystagmus were significantly greater under the noncycloplegic condition than under the cycloplegic condition. The changes in ocular refraction during the post-rotatory nystagmus were significantly and positively correlated with the amplitude of post-rotatory nystagmus under the noncycloplegic condition. The angle of convergence during post-rotatory nystagmus was significantly higher under the noncycloplegic condition than under the cycloplegic condition. The changes in the angle of convergence were significantly and positively correlated with the predicted accommodative convergence. Conclusions These findings suggest that the accommodation was functional during the post-rotatory nystagmus to compensate for the retinal image slip, and the accommodative convergence can help weaken the nystagmus.

Consecutive esotropia is a common and stereopsis-threatening consequence of surgery for intermittent exotropia. However, too little attention has been paid to the accommodative convergence per accommodation (AC/A) ratio in this condition. We aimed to describe the clinical features of patients who developed consecutive esotropia with a high AC/A following surgery for intermittent exotropia, compared to those with normal AC/A. In this retrospective cohort study, we identified 54 patients with consecutive esotropia who remained esotropic at one month after surgery. Patients were divided into two groups: normal AC/A and high AC/A groups. Clinical features and outcomes were compared between the two groups. Fourteen (25.9%) of the 54 were classified as high AC/A consecutive esotropia. Good preoperative control at near was the only significant preoperative factor associated with the development of high AC/A consecutive esotropia. Bifocal glasses were prescribed for all patients with high AC/A consecutive esotropia, and 11 (78.6%) of them achieved satisfactory alignment at distance and near fixations using bifocals. Patients with high AC/A consecutive esotropia had a significantly more successful alignment (0.9 vs. 13.0 prism diopters, p &lt, 0.001) and better stereopsis (67.9 vs. 670.0 arc seconds, p = 0.04) than the normal AC/A counterparts at the final follow-up. We suggest that high AC/A consecutive esotropia could be successfully managed by wearing bifocals in most cases. A high AC/A ratio in patients with consecutive esotropia may be considered as a clinical marker heralding a better prognosis.

BackgroundTo examine the clinical features of acute acquired comitant esotropia (AACE) and to evaluate the clinical effectiveness of a single injection of botulinum toxin type A (BTXA) on binocular visual function (BVF).MethodsThis retrospective, observational case series study enrolled patients with AACE examined from October 2018–May 2019. BTXA was injected into the both medial rectus muscles. The refractive error, best-corrected visual acuity (BCVA), stereoacuity, vergence, accommodation, the horizontal angle of deviation, and the gradient accommodative convergence/accommodation (AC/A) ratio were measured pre- and post-BTXA injection. Data pre- and postinjection were compared by the Wilcoxon signed-rank test. A Spearman correlation coefficient was calculated to explore the relationships between demographic characteristics and BVF.ResultsTwenty-two AACE cases were included. Compared with preinjection deviation, the postinjection deviation in the primary position was smaller for near (p p p = 0.003) and distance (p p = 0.021) and distance (p p = 0.011) and left (p = 0.004) eyes, and the gradient AC/A ratio was better at the third month after injection (p = 0.001). Stereoacuity was improved in 11 (50%), unchanged in 5 (22.73%) and decreased in 6 (27.27%) patients. The preinjection stereoacuity (p = 0.013,r = 0.522) and preinjection deviation for near (p = 0.015 r, = − 0.512) and distance (p = 0.009,r = − 0.541) were significantly associated with patient age.ConclusionsAACE is characterized by a high AC/A ratio and low accommodation. A single injection of BTXA is effective for AACE. Deviation, stereoacuity, and the therapeutic effect of BTXA may be correlated with patient age.

We present the first case series of patients with no systemic neurologic disease who experienced a spontaneous conversion from an initial exotropia to a sensory esotropia in the absence of strabismus surgery or chemodenervation. The patients in this series all were exotropic in the first 2 years of life, with the strabismic eye having decreased vision due to unilateral ocular pathology. All patients demonstrated spontaneous conversion to esotropia between 4 and 8 years of age and thereafter clinically demonstrated a high ratio of accommodative convergence to accommodation. There was no discernible relationship between refractive error and the pattern of spontaneous esotropia. The existence of this rare entity may support delayed surgical correction of strabismus in patients with sensory exotropia.

Purpose: To evaluate the sensory motor state, accommodation, and accommodative convergence to accommodation ratio (AC/A) in a cohort of non-amblyopic myopes with acquired concomitant esotropia (Bielschowsky esotropia (BE)). Methods: Refraction, near and far deviation, fusional amplitude (FA), near point of accommodation (NPA), AC/A (gradient method), and stereopsis were measured in a cohort of 26 patients (25 phakic and 1 pseudophakic, age: 14–60years) with BE, prospectively recruited from January to September 2019 at St. Orsola-Malpighi Hospital, Bologna, Italy. The Pearson’s correlation coefficient was used to correlate distance with near deviation, distance with near divergence FA and angle of deviation with FA (statistical significance: p values < 0.05). Results: Myopia range was 0–17.5 diopters (D) spherical equivalent (mean: 4.4D). A positive correlation resulted between distance (mean: 23.7 prism diopters/PD, range: 4–40PD) and near (mean: 23.7PD, range: 2–45PD) deviation (p < 0.00001) and between distance (mean: 12.6PD, range 0–34PD) and near (mean: 17.0PD, range 3–36PD) divergence FA (p < 0.00001). A non-significant correlation resulted between angle of deviation and divergent FA at near (p = 0.07) and distance (p = 0.13) fixation. NPA was within normal limits for age. AC/C ratio range was 0–8 (mean: 3). Twenty-three patients showed Randot stereopsis. Conclusions: BE shows high variability in the age of onset, degree of associated myopia, AC/A, and divergent FA. A little stronger near divergent FA can justify the better compensation at near fixation. These results show that uncorrected myopia, accommodation, and divergence paralysis do not concur with the genesis of BE.

Purpose: To determine the prevalence of ocular and visual anomalies in students with Autism Spectrum Disorder (ASD). Methods: This case-series in 2015-16 included students with ASD of two special schools of Bangalore, India. Comprehensive ocular and vision examination also included accommodation by dynamic retinoscopy and convergence. The amplitude of accommodation was calculated by Hofstetter minimum formula. The accommodative facility was measured by referring to the cycles of accommodative flippers, used ± 2.50D and 14 cycles/min considered as normal. Saccades were tested using Marsden ball movements. Additional eye testing at our institute was with Vision therapy system, ocular motility testing and alternate prism cover test. Result: The 120 students with ASD had a mean age of 12.9 ± 1.7 years. They included autism 58 (48.3%), ASD 27 (22.5%) and other 34 (28.3%). Spectacles correction was needed in 62 (51.7%) students. Refractive error included myopia (57; 92%), hyperopia (5; 8%), myopic astigmatism (3; 4.8%), and mixed astigmatism (2; 3.2%). The compliance of spectacle wear was 12/62 (19.4%) only. Strabismus was seen in 68 (56.7%) students. Accommodative convergence was 4 to 28 mm. Non-accommodative convergence was 4 to 37 mm. Pursuit movements were poor in 35 (29.2%), average in 39 (32.5%), good in 46 (38.3%) students. The saccadic eye movements were good in 100 (83.3%), average in 15 (12.5%) and poor in 5 (4.2%) students. Conclusion: More than half of students with ASD had at least one ocular morbidity. The commonest was refractive errors followed by strabismus. Periodic and comprehensive ocular assessment of autistic students is recommended.

PURPOSE: To study the outcome of botulinum toxin (BTX) treatment (group 1) in partially accommodative esotropia with high accommodative convergence/accommodation (AC/A) ratio, in comparison with bilateral medial rectus muscles recessions and posterior fixation (group 2). METHODS: In a retrospective comparative study, children aged 3-8 years old treated between 2011 and 2016, with partially accommodative esotropia with high AC/A ratio, deviation at distance of 10 prism diopters or more, and at least 1 year of follow-up, were included. Visual acuity, alternate prism and cover test, stereoacuity, biomicroscopy, and cycloplegic retinoscopy were carried out at initial, baseline visit, 6 months and 1 year after BTX injection or surgery. Main outcome variables were deviation at distance and near, improvement in stereoacuity, and percentage of success. We used multiple regression or proportional odds analysis to control for potential confounding variables. RESULTS: Of 95 patients, 84 were eligible, 48 children in group 1 and 36 in group 2. Deviation and stereoacuity were similar in the two groups at 6 months, but significantly better in the BTX group at 1 year (median distance deviation 0 prism diopters vs 5 prism diopters, p, JT received grant MINECO UAMA13-4E-2192

To measure the Accommodative Convergence (PD)/Accommodation ratio (D) (AC/A) in a cohort of visually normal participants using common clinical methods.AC/A ratios of 50 visually normal subjects were measured using the distance gradient (DG), near gradient (NG), gradient using synoptophore, (SG) and heterophoria (H) methods in line with current clinical practice.Median AC/A ratios for NG, DG, SG, and H were 2.0 (IQR 2.0), 1.0 (IQR 0.6), 1.0 (IQR 0.6), and 5.0 (IQR 1.7), respectively. There was a statistically significant difference in ratios calculated between all methods in the same subjects (p 0.05). There were differences in DG vs NG, DG vs H, SG vs H, and NG vs H (p 0.05); only DG vs SG did not differ significantly (p 0.05). Lens power toleration was found to affect AC/A ratio in DG (p 0.05) and latent deviation was significantly associated with (p 0.05) AC/A ratio in NG.Calculated AC/A ratios in this cohort were lower than historically cited normal (3-5:1) in all gradient methods. There were differences in AC/A values in the same subjects calculated with different gradient methods, indicating that these methods are not interchangeable and a universal normal range should not be applied for all methods.

Purpose Accommodative esotropia is a common cause of acquired esotropia. Pathogenesis varies among patients but usually includes excessive hyperopia and a high accommodative convergence/accommodation ratio or tight medial recti. The present study reviews an individualized treatment plan combining photorefractive keratectomy (PRK) and strabismus surgery to correct these problems. Design This study is a retrospective, interventional case series. Methods Records for 15 patients who were treated for accommodative esotropia were reviewed. Patient ages ranged from 11 to 19 years. PRK and strabismus surgery were performed on 11 patients, and PRK only on 4 patients. The goal was to create a physiologic refractive error, good visual acuity (VA), and straight eyes without correction. Results All patients were spectacle free at 6-month follow-up. Twenty-four of 30 eyes had VA equal to preoperative VA without correction. Three eyes had a 1-line reduction and 2-line reduction in VA. The alignment results were ±10 prism diopters in 13 of 15 patients. Spherical refractive outcomes were 18 of 30 eyes within 1 diopter (D) of target and 12 of 30 eyes within 2 D of target. Astigmatism refractive outcomes were 21 of 30 eyes 2 D. Two patients complained of halos at night, and 1 patient had peripheral corneal haze. Conclusion Simultaneous PRK and strabismus surgery is safe and effective in treating accommodative esotropia. An individualized treatment plan can result in a physiologic refractive error, good VA, and a spectacle-free existence.

Correlated color temperature (CCT) is an important feature of the LED luminaire. However, its influence on visual discomfort remains vague due to the lack of a comprehensive study based on ocular physiological parameters and psychological assessment. In this paper, the investigation was carried out by the measurement of ocular parameters and the collection of subjective score. Three physiological parameters were used including higher order aberrations, modulation transfer function, and the ratio of accommodative convergence to accommodation ratio. It is shown that CCT has significance influence on human eye, and the proper CCT for the ocular health of moderate myopia people is near 5000 K. In addition, the results imply that the perception of discomfort is caused by psychological perception rather than ocular fatigue.

Manar A Ghali Ophthalmology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt Purpose: To compare and evaluate the efficacy of two different surgical techniques for the treatment of near-distance disparity esotropia; combined resection–recession and recession–retroequatorial myopexy of medial rectus muscles. Patients and methods: This prospective study included 28 patients diagnosed with convergence excess esotropia who had worn their full cycloplegic refraction and/or bifocal glasses for at least 6 months and still had near-distance disparity esotropia. The patients were divided into 2 groups; Group I underwent combined bimedial rectus muscles resection 2.5mm from the insertion end with recession based on near-angle esotropia according to current surgical tables with 1 mm add of recession for each muscle, while Group II underwent bimedial recession based on far angle combined with retroequatorial myopexy at 13–14mm from insertion. A satisfactory result was defined as orthophoria or esotropia 10 ∆. Conclusion: The technique of combined resection–recession is safe, easy and more effective in the treatment of near-distance disparity esotropia regardless of the level of accommodative convergence/accommodation ratio, with stability of results though longer follow-up period is still needed. Keywords: near-distance disparity, esotropia, Ac/A ratio, retroequatorial myopexy, slanted recession

Intermittent distance exotropia is a deviation characterized by an exophoria at near fixation and manifest exotropia at distance fixation. There is normal binocular fusional vergence and stereoacuity at near fixation, but the eyes tend to diverge in bright sunlight, tiredness, day dreaming and the patient may close one eye in such circumstances. Prematurity is associated with numerous eye pathology, besides retinopathy of prematurity, amblyopia, refractive errors, it is also associated with a higher risk esotropia and exotropia. We report a case of a 5-year-old girl (preterm and very low birth weight) with an intermittent deviation of both eyes since three years. On her detailed ocular examination diagnosis of divergence excess intermittent exotropia with normal accommodative convergence to accommodation ratio was made. Bilateral lateral rectus recession was done using hang back technique. Postoperatively, the eyes were aligned normally thereby achieving orthotropia. This article reviews various neurophysiological aspects of intermittent divergent squint delineating the etiopathogenesis, classification system, and management options in intermittent exotropia.

The accommodative excess (AE) is the most prevalent dysfunction among the university students [1]. In this dysfunction, the patient hyper-accommodates, which implies an excessive accommodative convergence

The aim of the present study was to evaluate the effect of base-in prism on symptoms and clinical characteristics of young adults with convergence insufficiency.In this randomised clinical trial, 64 CI patients aged 18-38 years who presented to Bina Eye Hospital, Tehran, Iran between November 2018 and April 2019 were selected and randomly assigned to either prism or placebo groups. All participants underwent complete optometric examinations, including the measurement of visual acuity, objective and subjective refraction, and complete accommodative and binocular vision examinations. Clinical examinations were repeated after three months. The overall score of the Convergence Insufficiency Symptom Survey (CISS) was considered as the primary outcome measure. Secondary outcome measures included near exophoria, positive fusional vergence at near, near point of convergence, vergence facility, monocular accommodative facility, accommodative response, negative relative accommodation and accommodative convergence/accommodation (AC/A) ratio.The mean (S.D.) age of the participants was 25.5 (5.5) years and 44% of them were male. The mean CISS score was significantly lower in the prism group compared to the placebo group in the outcome examination (p 0.001). Moreover, the values of monocular accommodative facility, accommodative response, and negative relative accommodation were significantly higher in the prism group versus the placebo group (p 0.001). There was no significant difference in other parameters, including near positive fusional vergence, near point of convergence, vergence facility, and AC/A ratio between the two groups in the outcome examination (p 0.10).The base-in prism reduced symptoms in young adults with convergence insufficiency, while it had no significant effect on the near point of convergence, near positive fusional vergence, vergence facility and AC/A ratio. However, the results of this study only supports the symptomatic effectiveness of prism in the short term and further studies are needed to assess the long-term effect of prism.

Faden operation was first described in 1912. It weakens the muscle in its field of action without much slackening and alteration in the primary position. When combined with recession the weakening effect is more. It is a useful surgery in esotropia with high accommodative convergence, nystagmus blockage syndrome, dissociated vertical deviation, Duane's retraction syndrome with up or downshoots, and in sixth nerve paresis, where it is performed on the contralateral normal yoke muscle to increase the field of binocular vision. The conventional procedure is cumbersome due to small working space, entanglement of sutures, and posterior location of Faden site which is not easily accessible. We have modified the Faden operation by using a single 5-0 double-armed polyester suture, which is much easier and simpler to perform, and have done it in a series of small angle esotropias combined with recession. This paper demonstrates the surgical technique so that this surgery can be performed with ease by more surgeons.

Many studies have shown the benefits of augmented reality (AR) to improve manufacturing and control processes in industry. However, the presentation of AR content through optical see-through head-mounted displays may induce unnatural viewing conditions, which consequences on the user’s visual system have not been investigated yet. This study aimed at assessing whether using AR instructions to guide a manual task, i.e., conditions where the user is forced to repeatedly look at and accommodate in different planes to extract information from both real and virtual environments, could potentially impact the visual system of operators. A before/after design study was carried out, asking 26 participants to perform Lego assemblies for 30 min with either paper or AR instructions. The effects of using AR compared to paper instructions were evaluated both on binocular vision, with classical optometric measurements, and on visual fatigue, with the Virtual Reality Symptoms Questionnaire. No clinically significant differences in optometric measurements (far/near visual acuity, stereoacuity, phoria, convergence, fusional amplitude, accommodation amplitude, accommodative convergence) have been found between AR and paper instructions, and only negligible fatigue symptoms have been seen specifically for AR. Results from both objective and subjective measurements suggest that there is no impact of AR on the oculomotor system and that, in this specific case of use, AR can be safely used for production operators.

To report a patient with cyclic esotropia with a high accommodative convergence to accommodation (AC/A) ratio after surgical correction of intermittent exotropia who was found to have bilateral anomalous medial rectus muscle insertion sites. A 5-year-old girl developed intermittent esotropia on alternating days after undergoing bilateral lateral rectus recessions for correction of intermittent exotropia. Alternate prism and cover measurement of ocular alignment and binocular function was assessed on consecutive days. Surgical correction was performed for the full amount measured on a “crossed” day. On “straight” days, her eyes were orthotropic with normal binocular vision. Examination on “crossed” days revealed a left esotropia of 75 prism diopters (PD) at near fixation and 40 PD at distance fixation in primary gaze without fusion or stereopsis. The patient underwent bilateral medial rectus recessions in conjunction with posterior fixation sutures (MRP). During surgery, the distance from the limbus to the medial rectus muscle insertion was 3.5 mm bilaterally. Postoperatively, the cycle was broken, and the esotropia disappeared with no recurrence at the latest follow-up at 12 months. MRP is an effective procedure for correction of cyclic esotropia with a high AC/A ratio. Strabismus surgeons should design surgical strategies based on preoperative measurement of deviations at all distances and the anatomy of muscle insertions in patients with cyclic esotropia.

The purpose of this paper is to provide a systematized review of the published literature addressing accommodative and fusional convergence in intermittent exotropia. This paper will summarize a va...

Purpose The purpose of this study was to compare the results of medial rectus (MR) Faden recession (FR) with MR augmented recession (AR) in the management of large distant–near disparity (DND), in convergenceexcess, partially accommodative esotropia (ET) associated with a high accommodative convergence/accommodation (AC/A) ratio. Patients and methods This is a prospective interventional study of 31 patients with convergence excess partially accommodative ET associated with a high AC/A ratio. Patients were divided into two groups. Group FR, which contains 15 patients who were treated by bimedial FR, and group AR, which contains 16 patients who underwent augmented MR recession based on the angle of near deviation. Surgical success was defined as distant and near ET≤10 prism diopter with shrinkage of high AC/A ratio and high DND. Results Surgical success was achieved in 93.3% of cases in the FR group and in 81.2% of cases in the AR group. In the FR group, mean DND decreased from 33.3±11.5 to 3.06±2.08 prism diopter. For the AR group, mean DND decreased from 25.3±7.1 prism diopter preoperatively to 5.3±2.5 prism diopter postoperatively. The difference between both groups regarding reduction of DND was statistically significant (P

Convergence insufficiency (CI) is a dysfunction of binocular vision that is associated with various signs and symptoms in near work. However, CI screening is performed less frequently in adults than in children. We aimed to evaluate the ability of screening tests to discriminate CI from other binocular vision anomalies and normal binocular vision in young adults. One hundred eighty-four university students (age, 18–28 years) who underwent an eye examination due to ocular discomfort were included. Near point of convergence (NPC), phoria, accommodative amplitude, fusional vergence, the ratio of accommodative convergence to accommodation, relative accommodation, binocular accommodative facility, vergence facility, and the values corresponding to Sheard’s and Percival’s criteria were evaluated. Receiver operating characteristic (ROC) curve analysis for each test was also performed. The prevalence of CI ranged from 10.3% to 21.2%, depending on the signs and the presence of CI associated with accommodative disorders. Assessments based on NPC, Sheard’s criterion, and Percival’s criterion showed high discriminative ability, with the ability being higher between the CI and normal binocular vision groups than between the CI and non-CI groups. Sheard’s criterion showed the highest diagnostic performance in discriminating CI with three signs from the non-CI group. The cut-off values were 7.2 cm for NPC, -0.23 to 1.00 for Sheard’s criterion, and -4.00 to -2.33 for Percival’s criterion. Our results suggest that the use of Sheard’s criterion with NPC shows high performance for screening of CI.

PURPOSE To examine the impact of contact lens optical design on accommodative behaviour of children and the correlation between myopia progression and the accommodative response of the eye while wearing a contact lens designed for myopia control. METHODS A post-hoc analysis was conducted on data from a previously published myopia control trial. A total of 109 subjects (aged 8 to 11 years, myopia: -0.75 to -4.00 D) wore either a Control (single-vision, n = 57) or a Test (with positive spherical aberration, +SA, n = 52) soft contact lens, binocularly for 1 year. Accommodative response was measured as the subject observed targets at -1.00 to -4.00 D vergence using the Grand Seiko WAM-5500 open-field autorefractor (www.grandseiko.com). Slope of accommodative response (SAR) as well as distance and near phoria and stimulus accommodative convergence/accommodation (AC/A) were compared between each group at baseline without study lenses and at 1-week and 1-year visits with study lenses. The SAR was also compared to changes in axial length (AL) and spherical equivalent cycloplegic auto refraction (SECAR). RESULTS At baseline, there was no significant difference in SAR between the two study groups (ΔSAR = -0.039, p = 0.84). At 1 week, mean SAR of the Test group was significantly less than for the Control group (ΔSAR = -0.203, p

To investigate differences in the stimulus accommodative convergence/accommodation (AC/A) ratio using various techniques and accommodative stimuli, and to describe a method for determining the stimulus AC/A ratio.A total of 81 subjects with a mean age of 21 years (range, 20-23 years) were enrolled. The relationship between ocular deviation and accommodation was assessed using two methods. Ocular deviation was measured by varying the accommodative requirement using spherical plus/minus lenses to create an accommodative stimulus of 10.00 diopters (D) (in 1.00 D steps). Ocular deviation was assessed using the alternate prism cover test in method 1 at distance (5 m) and near (1/3 m), and the major amblyoscope in method 2. The stimulus AC/A ratios obtained using methods 1 and 2 were calculated and defined as the stimulus AC/A ratios with low and high accommodation, respectively, using the following analysis method. The former was calculated as the difference between the convergence response to an accommodative stimulus of 3 D and 0 D, divided by 3. The latter was calculated as the difference between the convergence response to a maximum (max) accommodative stimulus with distinct vision of the subject and an accommodative stimulus of max minus 3.00 D, divided by 3.The median stimulus AC/A ratio with low accommodation (1.0 Δ/D for method 1 at distance, 2.0 Δ/D for method 1 at near, and 2.7 Δ/D for method 2) differed significantly among the measurement methods (P 0.01). Differences in the median stimulus AC/A ratio with high accommodation (4.0 Δ/D for method 1 at distance, 3.7 Δ/D for method 1 at near, and 4.7 Δ/D for method 2) between method 1 at distance and method 2 were statistically significant (P 0.05), while method 1 at near was not significantly different compared with other methods.Differences in the stimulus AC/A ratio value were significant according to measurement technique and accommodative stimuli. However, differences caused by measurement technique may be reduced by using a high accommodative stimulus during measurements.

To review binocular and accommodative disorders documented after corneal or intraocular refractive surgery, in normal healthy prepresbyopic patients. A bibliographic revision was performed; it included works published before 1st July 2017 where accommodation and/or binocularity was assessed following any type of refractive surgical procedure. The search in Pubmed yielded 1273 papers, 95 of which fulfilled the inclusion criteria. Few publications reporting binocular vision and/or accommodative changes after refractive surgery in normal subjects were found. The reduction in fusional vergence is the most frequently reported alteration. Anisometropia is an important risk factor for postoperative binocular vision-related complaints. Most diplopia-related visual complaints, irrespective of the surgical procedure, were in fact misdiagnosed preoperative disorders. The preoperative evaluation of patients seeking spectacle/contact lens independence should include a complete binocular and accommodation assessment where parameters such as the phoric posture, accommodative amplitude and facility, near point of convergence, fusional reserves and accommodative convergence/accommodation coefficient are measured. This would allow the identification of risk factors that could compromise the success of the refractive surgery and cause clinical symptoms.

Purpose To study the influence of bifocal use on amblyopia treatment outcome in high accommodative convergence/accommodation (AC/A) ratio accommodative esotropia with deviation only at near. Design Retrospective comparative case series. Methods Setting : Tertiary referral center. Patients : Children with high AC/A ratio accommodative esotropia aged 3–8 years old, with deviation only at near with glasses, neutralized with bifocal lenses (follow-up 1 year). Intervention : Amblyopia was treated with patching. We compared bifocal and single-vision glasses users at 6 months and 1 year, with control of potential confounding variables (multiple regression). Main Outcome Measures : LogMAR lines of improvement in visual acuity of the amblyopic eye, and improvement in stereoacuity. Results Of 78 children, 61 were eligible. All patients wore single-vision glasses for 2 months (baseline visit), 46 of them changed to bifocals. Of 27 initially amblyopic children, 21 remained amblyopic at 2-month baseline (13 of them changed to bifocals). After adjustment for initial deviation, refraction, age, and amblyopia, improvement of visual acuity in the amblyopic eye was larger in the bifocal vs single-vision group at 6 months (mean 2.6 [95% confidence interval (CI): 1.9–2.9] logMAR lines vs mean 1.9 [95% CI: 0.5–2.2] logMAR lines, respectively, P = .01), but not at 1 year (mean 2.7 [95% CI: 2.2–3.1] logMAR lines vs mean 2.3 [95% CI: 1.6–3.1] logMAR lines, respectively, P = .3). Improvement of stereoacuity was not significantly different between the 2 groups. Conclusions Use of bifocals may provide a transient advantage, but improvement in visual acuity and stereopsis is equal with single-vision glasses over time.

This research tested the hypothesis that the successful treatment of convergence insufficiency (CI) with vision-training (VT) procedures, leads to an increased capacity of vergence adaptation (VAdapt) allowing a more rapid downward adjustment of the convergence accommodation cross-link. Nine subjects with CI were recruited from a clinical population, based upon reduced fusional vergence amplitudes, receded near point of convergence or symptomology. VAdapt and the resulting changes to convergence accommodation (CA) were measured at specific intervals over 15min (pre-training). Separate clinical measures of the accommodative convergence cross link, horizontal fusion limits and near point of convergence were taken and a symptomology questionnaire completed. Subjects then participated in a VT program composed of 2.5h at home and 1h in-office weekly for 12–14weeks. Clinical testing was done weekly. VAdapt and CA measures were retaken once clinical measures normalized for 2weeks (mid-training) and then again when symptoms had cleared (post-training). VAdapt and CA responses as well as the clinical measures were taken on a control group showing normal clinical findings. Six subjects provided complete data sets. CI clinical findings reached normal levels between 4 and 7weeks of training but symptoms, VAdapt, and CA output remained significantly different from the controls until 12–14weeks. The hypothesis was retained. The reduced VAdapt and excessive CA found in CI were normalized through orthoptic treatment. This time course was underestimated by clinical findings but matched symptom amelioration.

BACKGROUND AND PURPOSE When patients with intermittent exotropia show an increase in their near deviation after prolonged monocular occlusion, they have been said to have tenacious proximal fusion (TPF). That term is not adequately descriptive, since this finding can occur without the patient having been allowed to fuse. The purpose of this study is to investigate the possibility that this phenomenon is mediated by the preponderance of binasal retinal disparity and uncrossed localization that occurs with near fixation. PATIENTS AND METHODS Ten patients with intermittent exotropia who manifested TPF were measured at 6 m, 1/3 m, again at 1/3 m after 1 hour of monocular occlusion, and at 1/3 m with a peripheral crossed localization stimulating device (PCLSD) that simulated the retinal bitemporal disparity and peripheral crossed localization usually found with distance fixation. RESULTS For the ten patients, the mean measurement at distance was 28.3Δ±3.1, initially at near was 4Δ±3.9, at near after prolonged monocular occlusion was 25.3Δ±5.3, and at near with the PCLSD was 18.5Δ±4.1. The differences between the initial near measurement and the measurement with the PCLSD, and between the PCLSD and post-prolonged monocular occlusion were significant with P

Flicker is the lighting characteristic of electric light sources that is generally harmful to human health. In this study, subjects were set in lighting environments with different flickers, and required to finish the reading task within 45 minutes. Visual fatigue caused by different LED flickers and during the task were recorded and reflected by three visual function parameters: higher order aberrations (HOAs), modulation transfer function (MTF) and the ratio of accommodative convergence to accommodation ratio (AC/A). Significant differences were found to exist between the visual function variations of the subjects in lighting environments with different flickers, and people with higher flicker lighting showed lower variations of visual functions. It is manifested that LED luminaires with reduced flicker frequencies are more likely to cause visual fatigue.

To review the state of the art of Accommodative Esotropia (AE) through careful study of what has been reported up to the point in literature. A literature search was done on PubMed using key words including “Accommodative esotropia”, “Infantile esotropia”, “Strabismus” and “Accommodation”. We systematically reviewed and critically appraised what has been written about AE and we tried to analyze that according to the current management of AE. Accommodative Esotropia (AE) is a form of strabismus characterized by convergent misalignment of the visual axes that can be associated with hyperopia and abnormal fusional divergence. Also abnormal accommodative convergence/accommodation ratio could be found. In lots of cases, AE initially presents as an intermittent esodeviation at age 1.5 to 4 years. The prevalence of AE has been estimated near 1-2% in the United States. The only treatment with an optical correction usually is successful in re-establishing alignment, but surgical correction is necessary in approximately 30% of cases.

Purpose To report long-term motor and sensory outcomes after surgery for the nonaccommodative component of partially refractive accommodative esotropia (PRAET). Methods The medical records of consecutive patients ≤11 years old operated for the nonaccommodative component of PRAET and followed postoperatively for at least 10 years were retrospectively reviewed. Results A total of 47 patients were included (median age, 3.0 years). The mean postoperative follow-up was 12.15 ± 2.05 years (range, 10.00-17.50 years). Overall, 23 patients (49%) had surgical success; 10 (21%), decompensation; and 7 (15%), esotropia with a high ratio of accommodative convergence to accommodation (AC/A) or consecutive exotropia. The median age at surgery, mean cycloplegic refraction, median near and distance deviation, presence of binocular vision, and amblyopia did not predict decompensation, a high AC/A ratio esotropia, and consecutive exotropia. Eight patients (18%) achieved stereopsis. Patients with an older age at onset (2.87 ± 1.31 years) and a shorter duration of strabismus (≤4 years) achieved better stereopsis. Conclusions Nearly half of our patients with PRAET achieved a successful ocular alignment after surgery for the nonaccommodative component. Some developed decompensation, a high AC/A ratio esotropia, or consecutive exotropia. Few patients achieved stereopsis. Older age at onset and a shorter duration of strabismus predicted a better stereopsis outcome.

Purpose To report the long-term ocular alignment outcomes of patients with accommodative esotropia. Methods The medical records of consecutive patients ≤12 year of age diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10Δ with full hyperopic correction) and followed for at least 10 years were retrospectively reviewed. Results A total of 107 patients were included (mean age, 4.81 ± 2.64 years). The mean follow-up period was 12.02 ± 2.25 years (range, 10-21 years). At the first examination performed 10 years after spectacle correction (mean, 10.2 years), 85 patients (79%) had orthophoria or esotropia ≤10Δ at both near and distance fixation, 14 (13%) had consecutive exotropia, 5 (5%) had decompensation and 3 (3%) had esotropia with a high ratio of accommodative convergence to accommodation (AC/A). The mean time interval between presentation and prescription of full hyperopic correction, initial cycloplegic refraction, and presence of amblyopia was not associated with consecutive exotropia, decompensation, or a high AC/A ratio esotropia. Conclusions Whereas most patients with refractive accommodative esotropia maintained normal long-term ocular motility with spectacle treatment, some developed consecutive exotropia, nonaccommodative esotropia, or esotropia with a high AC/A ratio.

Purpose: To identify variables associated with myopia progression and to identify any interaction between accommodative function, myopia progression, age, and treatment effect in the Cambridge Anti-Myopia Study. Methods: Contact lenses were used to improve static accommodation by altering ocular spherical aberration, and vision training was performed to improve dynamic accommodation. One hundred forty-two subjects, aged 14–21 years, were recruited who had a minimum of −0.75D of myopia. Subjects were assigned to contact lens treatment only, vision training only, contact lens treatment and vision training, or control group. Spherical aberration, lag of accommodation, accommodative convergence/accommodation (AC/A) ratio, accommodative facility, ocular biometry, and refractive error were measured at regular intervals throughout the 2-year trial. Results: Ninety-five subjects completed the 24-month trial period. There was no significant difference in myopia progression between the four treatment groups at 24 months. Age, lag of accommodation, and AC/A ratio were significantly associated with myopia progression. There was a significant treatment effect at 12 months in the contact lens treatment group in younger subjects, based on a median split, aged under 16.9 years (p = 0.005). This treatment effect was not maintained over the second year of the trial. Younger subjects experienced a greater reduction in lag of accommodation with the treatment contact lens at 3 months (p = 0.03), compared to older contact lens treatment and control groups. There was no interaction between AC/A ratio and contact lens treatment effect. Conclusions: Age, lag of accommodation, and AC/A ratio were significantly associated with myopia progression. Although there was no significant treatment effect at 24 months, an interaction between age and contact lens treatment suggests younger subjects may be more amenable, at least in the short term, to alteration of the visual system using optical treatments.

Objectives.This study aimed to compare changes in ocular status after 3D TV viewing under three modes of illumination and thereby identify optimal illumination for 3D TV viewing.Methods.The following measures of ocular status were assessed: the accommodative response, accommodative microfluctuation, accommodative facility, relative accommodation, gradient accommodative convergence/accommodation (AC/A) ratio, phoria, and fusional vergence. The observers watched 3D television for 90 minutes through 3D shutter glasses under three illumination modes: A, complete darkness; B, back illumination (50 lx); and C, front illumination (130 lx). The ocular status of the observers was assessed both before and after the viewing.Results.After 3D TV viewing, the accommodative response and accommodative microfluctuation were significantly changed under illumination Modes A and B. The near positive fusional vergence decreased significantly after the 90-minute 3D viewing session under each illumination mode, and this effect was not significantly different among the three modes.Conclusions.Short-term 3D viewing modified the ocular status of adults. The least amount of such change occurred with front illumination, suggesting that this type of illumination is an appropriate mode for 3D shutter TV viewing.

Purpose To evaluate the changes in the stimulus and response Accommodative Convergence to Accommodation (AC/A) ratio following vision therapy (VT) in Convergence Insufficiency (CI). Methods Stimulus and response AC/A ratio were measured on twenty five CI participants, pre and post 10 sessions of VT. Stimulus AC/A ratio was measured using the gradient method and response AC/A ratio was calculated using modified Thorington technique with accommodative responses measured using WAM-5500 open-field autorefractor. The gradient stimulus and response AC/A cross-link ratios were compared with thirty age matched controls. Results Mean age of the CI and control participants were 23.3 ± 5.2 years and 22.7 ± 4.2 years, respectively. The mean stimulus and response AC/A ratio for CI pre therapy was 2.2 ± 0.72 and 6.3 ± 2.0 PD/D that changed to 4.2 ± 0.9 and 8.28 ± 3.31 PD/D respectively post vision therapy and these changes were statistically significant (paired t-test; p

Aim To determine the association between the binocular vision and an abnormal head posture (AHP) when watching television (TV) in children 7-14y of age. Methods Fifty normal children in the normal group and 52 children with an AHP when watching TV in the AHP group were tested for spherical equivalents, far and near fusional convergence (FC) and fusional divergence (FD) amplitudes, near point of convergence, far and near heterophoria, accommodative convergence/ accommodation ratio and stereoacuity. The values of these tests were compared between the two groups. The independent t test was applied at a confidence level of 95%. Results The far and near FC amplitudes and far FD amplitudes were lower in the AHP group (the far FC amplitudes: break point 13.6±5.4(Δ), recovery point 8.7±5.4(Δ). The near FC amplitudes: break point 14.5±7.3(Δ), recovery point 10.3±5.1(Δ). The far FD amplitudes: break point 3.9±2.7(Δ), recovery point 2.6±2.3(Δ)) compared with those in the normal group (the far FC amplitudes: break point 19.1±6.2(Δ), recovery point 12.4±4.5(Δ). The near FC amplitudes: break point 22.3±8.0(Δ), recovery point 16.1±5.7(Δ). The far FD amplitudes: break point 7.0±2.1(Δ), recovery point 4.6±1.9(Δ)). Other tests presented no statistically significant differences. Conclusion An association between the reduced FC and FD amplitudes and the AHP in children when watching TV is proposed in the study. This kind of AHP is considered to be an anomalous manifestation which appears in a part of puerile patients of fusional vergence dysfunction.

To analyze the binocular function changes produced on subjects undergoing overnight orthokeratology (OK) treatment over short-term (3 months) and long-term (3 years) wear. A prospective, longitudinal study on young adult subjects with low to moderate myopia was carried out. Binocular function was assessed by the following sequence of tests: Distance and near horizontal phoria (Von Graefe technique), distance and near horizontal vergence ranges (Risley rotary prisms), accommodative convergence/accommodation (AC/A) ratio (gradient method) and the near point of convergence (standard push-up technique). The short-term sample consisted of: 21 subjects in the control group, 26 in a corneal refractive therapy (CRT) treatment lenses group and 25 in a Seefree treatment lenses group. Those subjects were evaluated at baseline and at a 3-month follow-up visit. Twenty one subjects were old CRT wearers that attended a 3-year follow-up visit (long-term group). A statistically significant difference over the 3-month treatment was found for divergence at distance: the break point decreased 1.4 Δ (p = 0.0006) in the CRT group and the recovery point increased 1.2 Δ (p = 0.001) in the Seefree group. Also, the Seefree group had an exophoric trend of 2.3 Δ at near (p = 0.02) and a base-out break decrease of 2.3 Δ (p = 0.03). For the long-term group, only the base-out break point at distant vision showed a statistically significant difference of 4.9 Δ (p = 0.02). OK induces minimal changes in the binocular function for either short-term or long-term periods, apart from a near exophoric trend over the short-term period.