Monocular Accommodative Facility Research Articles

Influence of Blood Glycemia Levels in Refraction, Binocular Vision and Accommodation: A Case Report

This case report provides us with insight on how blood glycemia affects refraction, vergence and accommodation in a single diabetic patient. A 21-year-old type I diabetic woman was the subject studied in this report. Refraction, near and far fusional vergence ranges, near point of convergence, monocular accommodative facility, amplitude of accommodation, lag of accommodation, and near and far phoria, were measured before and after controlled caloric intake and insulin injection. Measurements were taken a total of 10 times, once a week for 10 consecutive weeks. Blood glycemia levels were provided by a measuring device that was attached to the patient’s body at all times. Statistically significant differences were found in the glucose levels before and after lunch, p = 0.041, sphere refraction of the right eye, p = 0.016, but not in the left eye, p = 0.051. Accommodative facility in both right and left eyes, p = 0.019, p = 0.028, respectively, and amplitude of accommodation, p = 0.016, p = 0.019, right and left eyes, respectively were statistically different before and after insulin injection. In a 21-year-old subject with type I diabetes, a diminution in blood glucose levels influences refractive myopic state, and is associated with a decrease in accommodative facility and in amplitude of accommodation.

Objective and subjective assessment of accommodative insufficiency.

A variety of subjective and objective procedures are available to measure the amplitude of accommodation. However, it is unclear whether the standard criterion of Hofstetter's minimum minus 2 D can be used to diagnose accommodative insufficiency with each of these techniques. The use of objective dynamic retinoscopy and three subjective techniques to diagnosis accommodative insufficiency was examined. A total of 632 subjects between 8 and 19 years of age were enrolled. Accommodative lag, monocular accommodative facility, and subjective (push-up, modified push-down, and minus lens) and objective (dynamic retinoscopy) amplitude of accommodation were quantified. Accommodative insufficiency was diagnosed based on Hofstetter's minimum minus 2 D for each subjective method, as well as adding an additional subjective criterion (either accommodative lag exceeding 0.75 D or monocular accommodative facility falling below the age-expected norms). The prevalence of accommodative insufficiency was lowest and highest with the push-up (7.9 and 1%) and dynamic retinoscopy (94 and 12%) procedures when measured without and with the additional subjective criteria, respectively. Comparing the validity of dynamic retinoscopy against the traditional criterion, moderate to low sensitivity and high specificity were found. However, adding the additional subjective criteria improved the findings with moderate to high sensitivity and high specificity. Using a cutoff for dynamic retinoscopy of 7.50 D showed moderate diagnostic accuracy based on likelihood ratios. It is clear that a revised definition of accommodative insufficiency is required, which must include the method of assessing accommodation. The various objective and subjective methods for quantifying the amplitude of accommodation are not interchangeable, and subjective assessment does not provide a valid measure of the accommodative response.

Comparison of changes in ocular aberrations with accommodation and accommodative facility

Aims/Purpose: This study aimed to analyse whether a relationship exists between subjectively measured monocular Accommodative Facility (AF), the magnitude of the revolution‐symmetric Zernike coefficients C20, C40 and C60, and the objectively measured Accommodative Response (AR).Methods: A total of 66 eyes, from 33 healthy young volunteers (26 women and 10 men) with a mean age of 25.12 ± 3.40 years (range age 20–30) participated in this study. Three measurements were made for each eye with the aberrometer Hartmann‐Shack (IRX3, Imagine Eyes, Orsay, France). The stimulus vergence was increased from 0 to 5 D (near vision) in steps of 0.5 D. The AR for each Zernike coefficient was calculated as the difference between the value at 5 D and the value at 0 D, for 4.0 mm pupil size. Monocular assessment of AF was assessed monocularly and conducted at 40 cm ± 2.00 D flippers. Statistical analysis was performed to determine a relationship between the Zernike coefficients, AR and AF. The coefficient of determination (R‐squared) was calculated to measure the proportional amount of variance.Results: The results showed that the highest values of R‐squared were obtained for the C20 coefficient measured at 5D of accommodation (R2 = 0.196, p < 0.01). Lower values were obtained for C40 and C60. The R‐squared values decreased from 0D (R2 = 0.097, p = 0.10) to 5D (R2 = 0.044, p = 0.60) for C40. However, there was an increase in R‐squared values from 0D (R2 = 0.0081, p = 0.47) to 5D (R2 = 0.058, p = 0.05) for C60.Conclusions: No clear trends were found when comparing the Zernike coefficients C20, C40 and C60, analysed in three stages of accommodative demand compared with the accommodative facility measured.The Zernikes coefficients analysed do not explain the differences in AF in this sample of young adult healthy eyes. However, there was found a trend that deserves further investigation.

Associations between Accommodative Facility, Age, and Refractive Errors in Early, Older Adolescent Myopes and Emmetropes.

Accommodative functions are known to differ between myopes and emmetropes. It is not known whether accommodative facility differs at near between younger adolescent and older adolescent myopes and emmetropes. To examine whether accommodative facility differs at near between younger and older adolescent myopes and emmetropes. 119 participants aged between 11-21 years were recruited. Refractive error was measured using cycloplegic retinoscopy. Near monocular accommodative facility was measured for 60 seconds, using a +2.00D/-2.00D handheld flipper and N6 print at 40 cm. Participants were classified into two age groups: (i) younger adolescents (range: 11-14 years) and (ii) older adolescents (range: 15-21 years). The criterion applied to define myopia was spherical equivalent refraction: ≥-0.50D) and spherical equivalent refraction: -0.25D to +0.75D) for emmetropia. Univariate Analysis of Variance was carried out to analyze the interaction of age groups and refractive groups on near accommodative facility. Near monocular accommodative facility was significantly lower (p = 0.003) in younger adolescents (5.87 ± 3.72 cpm) compared to older adolescents (8.11 ± 4.11 cpm), indicating age as a significant main effect (F1,115 = 13.44; p = 0.0001). Younger adolescent emmetropes (4.77 ± 2.05 cpm, p = 0.005) and younger adolescent myopes (6.48 ± 4.12 cpm, p = 0.022) had significantly lower monocular near accommodative facility compared to older adolescent emmetropes (9.52 ± 3.27 cpm), but did not show any difference when compared to older adolescent myopes (p > 0.05). This indicates a significant association linking age and refractive error to near accommodative facility (F1,115 = 4.60; p = 0.03). Younger adolescent myopes and younger adolescent emmetropes had reduced monocular near accommodative facility than older adolescent emmetropes, but not when compared to older adolescent myopes.

Establishing Normative Values for Amplitude of Accommodation and Accommodative Facility among University Students in Malawi

Aim: The study aimed to examine the distribution of Accommodative Facility (AF) and Amplitude of Accommodation (AA) and compare the findings with established guidelines.
 Place and Duration of Study: Mzuzu University, Malawi. Between May and July 2022.
 Methods: This cross-sectional study was conducted among students at Mzuzu university in Malawi. We recruited 77 students using a stratified random sampling technique. The participants' age ranged from 16 to 35 years of age. We measured AA using the push-up method while AF was measured using +/- 1.50 Diopters (D) flippers. Both techniques utilized black reading material on white background held at 40 centimeters (cm). Next, we measured the accommodation facility by counting the number of Cycles per Minute (c/m). We utilized the Pearson correlation test and the One-way ANOVA where appropriate. The value of p< 0.05 was considered statistically significant. 
 Results: The participants comprised 44 (57.1%) males and 33 (42.9%) females. Monocular AA was 10.04D (SD=2.71) and Binocular AA was 10.51 (3.641). The difference was statistically significant (p=0.04). While Monocular AF and Binocular AF were 9 c/m (SD= SD=1.84) and 8.96 (SD=1.539) respectively but the difference was non-significant (p=0.868). AF and AA were not significantly different between males and females. All the parameters decreased with age. The measured AA was significantly higher than using Hofstetter’s formula.
 Conclusion: The study provides a cut-off value for practitioners diagnosing Accommodation anomalies. However, indices in the study differ from the well-established guidelines hence practitioners should endeavor to perform the clinical assessment instead of relying on equations.

Near work symptoms and measures of accommodation in children

ABSTRACT Clinical relevance Some children experience significant symptoms while doing near work, and accommodative deficits can be a contributory factor. However, studies investigating near work symptoms in children are sparse. Background To investigate the association between clinical and objective measures of accommodation and near point symptoms. Methods Twelve asymptomatic and 14 symptomatic children (mean age = 11.1 and 11.8 years, respectively) based on their Convergence Insufficiency Symptom Survey scores participated in the study. The clinical measures of accommodation were monocular amplitude of accommodation, monocular accommodative facility, and monocular estimation method. Objective measurements of the accommodative stimulus response function were recorded with a WAM-5500 autorefractor for two consecutive minutes at five viewing distances (0.33, 2, 3, 4, and 5 Dioptres [D]). Accommodative findings were compared between the groups using the Mann–Whitney U-tests. Spearman’s rank correlation coefficient was used to assess the association between symptoms and clinical and objective measures of accommodation. Results The mean CISS scores were 32.8 and 7.3 for the symptomatic and asymptomatic groups, respectively (p = <0.001). The symptomatic group showed a reduced accommodative functions compared to the asymptomatic group (p = 0.002 for accommodative facility, p = 0.04 for accommodative amplitude, p = 0.029 and 0.01 for objective measures of accommodation at 4D and 5D viewing distance, respectively). Clinical tests of accommodative amplitude and facility (correlation coefficient = −0.407 and −0.54, respectively) showed the highest correlation with the CISS scores, compared to the objective measures of accommodation. Conclusion Clinical tests of accommodation showed a greater association with symptoms than objective measures of accommodation in children aged 8–16 years. In children presenting with visual discomfort symptoms, measurement of accommodative amplitude and facility should be considered.

Changes in Accommodative and Binocular Function following Phakic Intraocular Lens for High and Low-to-Moderate Myopia.

The aim was to evaluate accommodative and binocular function of phakic intraocular lens implantable collamer lens (ICL) in high and low-to-moderate myopia. Prospective comparative cohort study with 38 myopic patients who underwent ICL implantation were divided into two groups of 19 patients, each one based on the spherical equivalent (SE): high-power (SE ≤ −6 D) and low-to-moderate (SE > −6 D). The push-up amplitude of accommodation (AA), monocular accommodative facility (MAF), distance and near ocular deviation, near convergence amplitude, near point convergence (NPC), stereopsis, and accommodative convergence/accommodation (AC/A) ratio were assessed before surgery and 1 week and 1 month postoperatively. The mean residual refractive error at 1 month after surgery improved in both groups, 0.18 ± 0.34 D and 0.09 ± 0.26 D, respectively (p < 0.001). There was a significant decrease in AA in both groups between preoperatively and at 1-week (p = 0.001; p = 0.008, respectively) and 1-month follow-up (p = 0.001; p = 0.008). For the rest of the binocular measurements, no statistically significant postoperative changes were found in any group. This finding suggests follow-up studies on amplitude of accommodation in phakic intraocular lens ICL implantation.

Binocular Function in Different Gaze Positions.

PurposeTo evaluate varied aspects of binocular function in multiple gaze positions.MethodsIn 2018, this cross-sectional study was conducted on 21 participants (male = 11) with an age range of 19–25 years. Having emmetropia and 10/10 visual acuity in both eyes were conditions of the inclusion criteria for the cross-sectional study. The following aspects of binocular function including amplitude of accommodation (AA), near point of convergence, near phoria, and monocular accommodative facility were evaluated in five gazes (primary, upward, downward, left, and right) for all subjects.ResultsNear point of convergence values showed significant differences in all gaze positions (P 0.001). The lowest near point of convergence value was seen in the primary gaze (2.69 cm) and the downward gaze (3.47 cm) and the highest near point of convergence value was seen in the left gaze (7.5 cm). There was also a significant difference in the amplitude of accommodation among the upward, downward, and the primary gaze (P 0.001) positions but no difference was observed among the temporal, nasal, and the primary gaze positions. There was a significant difference in near phoria between the upward gaze and the primary gaze (P = 0.008) while no significant differences were observed among the other gazes. There was no significant variance in the monocular accommodative facility among the different gaze positions (P = 0.175).ConclusionThe results of this study indicated variations that exist in the convergence and accommodation reflex functions in multiple gaze positions, which proved to be more prominent in the convergence system. Although the accommodative sufficiency evaluation was inconsistent among the multiple gaze positions, the accommodative facility evaluation was consistent in all gazes.

Virtual reality-based vision therapy versus OBVAT in the treatment of convergence insufficiency, accommodative dysfunction: a pilot randomized controlled trial

BackgroundVirtual reality is being increasingly applied in vision therapy. However, the differences in effectiveness, optimal treatment cycle, and prognosis between virtual reality-based vision therapy and traditional therapies remain unknown. The purpose of this study was to compare the effectiveness of virtual reality-based vision therapy and office-based vergence/accommodative therapy in young adults with convergence insufficiency or accommodative dysfunction.MethodsThe patients were randomly assigned to either the virtual reality-based vision therapy group or the office-based vergence/accommodative therapy group. The vision therapy lasted 12 weeks (1 h/week) in both groups. Binocular visual functions (vergence and accommodation) were measured and a subjective questionnaire-based assessment was performed at baseline and after 6 and 12 weeks of therapy.ResultsIn total, 33 patients with convergence insufficiency and 30 with accommodative dysfunction completed the study. After 12 weeks of treatment for convergence insufficiency, the Convergence Insufficiency Symptom Survey score (F2,31 = 13.704, P < 0.001), near point of convergence (F2,31 = 21.774, P < 0.001), positive fusional vergence (F2,31 = 71.766, P < 0.001), and near horizontal phoria (F2,31 = 16.482, P < 0.001) improved significantly in both groups. Moreover, the monocular accommodative amplitude (F2,25 = 22.154, P < 0.001) and monocular accommodative facility (F2,25 = 86.164, P < 0.001) improved significantly in both groups after 12 weeks of treatment. A statistically significant difference was observed in monocular accommodative facility (F1,25 = 8.140, P = 0.009) between the two groups, but not in other vergence and accommodative functions (0.098 < P < 0.687).ConclusionVirtual reality-based vision therapy significantly improved binocular vision functions and symptoms in patients with convergence insufficiency and accommodative dysfunction, thereby suggesting its effectiveness as a new optional or additional treatment for young adults with these conditions.Trial registrationThis study was registered at the Chinese Clinical Trials Registry on 16/04/2019 (identifier: ChiCTR1900022556).

Vision-related symptoms, accommodative and binocular vision performance in young diabetics vs. normal controls.

To compare accommodative and binocular vision performance between young diabetic subjects and normal controls, and to investigate the correlation of accommodative/binocular indices with the severity of diabetes. Thirty young subjects with diabetes mellitus (DM) and 30 age-matched normal controls were recruited in this hospital-based cross-sectional study. DM was diagnosed by a haemoglobin A1c (HbA1c) higher than 6.5%. The status of vision-related symptoms was examined by the convergence insufficiency symptoms survey (CISS). All participants underwent a complete optometric examination including visual acuity measurement, objective and subjective refraction, accommodative and binocular vision assessments. All study participants were between 18 and 40years of age. There were no statistically significant differences in best-corrected visual acuity (BCVA), sphere, cylinder and spherical equivalent refraction (SE) between the diabetes and control groups. The median near point of convergence (NPC) was significantly more remote in diabetics compared with the control group. Mean accommodative amplitude (AA) and vergence facility (VF) and the median monocular accommodative facility (AF) were significantly lower in diabetic subjects compared with normal controls. In addition, the median accommodative lag in the diabetic group was significantly higher than the control group. A significantly higher percentage of the diabetic group were symptomatic (26.6%), compared with the controls (6.6%). The NPC and accommodative lag showed a significant positive correlation with the HbA1c level, while VF, AA and AF exhibited a significant negative correlation with HbA1c. Aspects of accommodative and binocular vision performance are strongly affected by DM. There is also a significant correlation between accommodative and binocular disorders with the severity of DM. A significant percentage of young subjects with DM have severe vision-related symptoms.

Binocular Function Parameters in Elite Football Players

ABSTRACT Background To investigate the binocular function in elite football players, and to analyze the differences (i) between athletes who play in different positions and (ii) between players of different ethnicities. Methods We screened 102 professional football players from four teams. The screening consisted of the measurement of refractive error. The binocular function parameters evaluated were: horizontal and vertical ocular alignment for distance (DF) and near fixation (NF), the values of break and recovery for negative and positive fusional vergences at DF and NF, vergence facility at NF, monocular accommodative facility at NF, near point of convergence (NPC) (break and recovery points), and NF stereopsis. All the athletes were men with a mean age of 24.6 ± 4.1 years. Results No statistically significant differences were found based on the athletes’ ethnicity, except for ametropia prevalence, negative fusional vergences at DF, and NPC. We verified a statistically significant difference for the value of the break of negative fusional vergence at DF. The values found for Arab athletes are higher by more than 2 prism diopters than athletes of other ethnicities (p = .021). Arab athletes also show NPC values more distant than other athletes (p = .019, and p = .002 for break and recovery, respectively). Conclusion Arab athletes have some binocular function parameters better than the remaining athletes, in particular when compared to Caucasian athletes. When compared to reference studies, athletes’ binocular function seems to be better than those of the general population.

Diagnostic accuracy of indigenously developed computer-based binocular vision assessment.

CONTEXT:The increased prevalence of nonstrabismic binocular vision anomalies (NSBVA) has given rise to the need for cost-effective screening and diagnostic tools.AIMS:The aim of the study is to assess the efficacy of an indigenously developed computer-based binocular vision assessment software (Train Your Eyes®) in screening NSBVA.SUBJECTS AND METHODS:Subjects who visited the binocular vision clinic of a tertiary eye care center with asthenopic symptoms between January 2019 and January 2020 were included in the study. Patients with other ocular comorbidities and stereopsis poorer than 500 arc seconds were excluded. All subjects underwent a comprehensive eye examination followed by binocular vision assessment using both the manual and computer-based methods.STATISTICAL ANALYSIS USED:Receiver operating characteristic (ROC) curves were utilized to choose the cut-off points that maximize the sensitivity and specificity.RESULTS:The mean (standard deviation) age of 88 subjects was 22 (4.5) years with 34 males. Based on the conventional manual assessment, 71 (81%) were diagnosed to have NSBVA and 17 (19%) had normal binocular vision. Based on the ROC analysis, the following cut-off points are proposed: 14 prism diopter (PD) for near positive fusional vergence amplitudes, 4.5 PD for near negative fusional vergence amplitudes, 4.5 cycles per minute (cpm) for binocular accommodative facility, and 3.5 cpm for monocular accommodative facility. All the binocular vision parameters demonstrated statistical significance in the ROC analysis (P < 0.05).CONCLUSIONS:The software-based screening tool was found to be highly sensitive in identifying NSBVA and thus could be used as a potential screening tool in the clinic and community.

Effectiveness of Therapy for the Treatment of Accommodative Insufficiency: An Open Pilot Study

Background: To evaluate improvements in clinical measures and symptoms in children and young adults with accommodative insufficiency in an open trial of office-based vergence and accommodative therapy. Methods: Major eligibility requirements included ages 9 to 30 years and amplitude of accommodation (AA) ≥2 diopters (D) below Hoffstetter’s minimum. Participants completed 8 weekly, 1-hour sessions of office-based vergence and accommodative therapy. Therapy procedures followed the Convergence Insufficiency Treatment Trial (CITT) therapy protocol with emphasis on accommodative procedures. Clinical measures of accommodation and symptoms (Convergence Insufficiency Symptom Survey [CISS]) were assessed at baseline and after therapy. Results were evaluated using the Student’s t test and Kruskal-Wallis test. Repeatability of CISS scores at baseline was assessed using Bland Altman 95% Limits of Agreement (LoA) and Interclass Correlation Coefficient (ICC). Results: Eighteen participants (mean age 17.4 ± 8.0 years) were enrolled; sixteen completed the study. The mean AA improved significantly from 5.5D OD and OS at baseline to 12.4D OD and 12.8D OS at outcome (p&lt;0.001). Mean monocular accommodative facility (AF) also increased significantly in both eyes from 6.6 cycles per min (cpm) OD and 7.4cpm OS at baseline to 14.2cpm OD and OS at outcome (p≤0.0009). Amplitude-scaled monocular AF also showed significant improvements (p≤0.034 for both). Mean CISS score improved 10.50 points (p=0.0003). Significantly greater improvements in AA were observed in children (9.0D) than in adults (4.3D) in the right eye (p=0.007 for both comparisons). Conversely mean improvement in CISS score was significantly greater in adults than in children (p=0.039). Repeated CISS scores differed by, on average,1.47 points (95% limits of agreement:-5.19, 8.13; p=0.12). The ICC was 0.95 with a 95% confidence interval of 0.87 to 0.98. Conclusion: Eight weekly sessions of office-based accommodative vergence therapy combined with homebased- reinforcement therapy resulted in improvements of symptoms and clinical measures of accommodation in children and young adults with accommodative insufficiency.

Normative Data for Parameters of Accommodation in African Schoolchildren.

The reported interracial differences in normative data for parameters of accommodation call for investigating population-specific normative values. The study investigated and presents expected data for accommodative parameters among Ghanaian children. This study aimed to determine expected values for parameters of accommodation among schoolchildren in the Central Region of Ghana. This prospective cross-sectional study used a multistage cluster sampling approach. Normal participants were asymptomatic (Convergence Insufficiency Symptom Survey score ˂16), with unaided visual acuity or best-corrected visual acuity of 0.0 or better logMAR for each eye and having no ocular disease or no manifest strabismus. Normal participants underwent push-up and minus-lens-to-blur amplitude of accommodation tests, accuracy of accommodative response (using the monocular estimation method), and monocular and binocular accommodative facility testing. A total of 1261 normal participants within ages 11 to 17 years (mean, 14.75 ± 1.53 years) met the inclusion criteria. The mean normative data for the population include push-up amplitude of accommodation (14.04 ± 2.95 D), minus-lens-to-blur amplitude of accommodation (12.33 ± 2.55 D), and accuracy of accommodative response using the monocular estimation method (0.62 ± 0.22 D), monocular accommodative facility (9.80 ± 3.20 cycles per minute), and binocular accommodative facility (9.40 ± 3.30 cycles per minute). Age-predicted linear regression equations for the amplitude of accommodation are push-up amplitude of accommodation (16.74 - 0.18 × age in years) and minus-lens-to-blur amplitude of accommodation (15.7 - 0.23 × age in years). The study provides normative data for accommodative parameters that clinicians may use with Ghanaian populations of similar ages.

Prevalence of binocular vision dysfunctions in professional football players

ABSTRACT Clinical relevance The extent of binocular vision dysfunction in elite soccer players needs to be determined as it may impact performance. Background The purpose of the study was to investigate the prevalence of binocular vision dysfunctions in elite soccer players. Methods One hundred and seven professional soccer players were evaluated. Refractive error was measured and the following binocular vision parameters were assessed: horizontal and vertical phoria for distance and near vision, the values of break and recovery for negative and positive fusional vergences at distance and near vision, vergence facility at distance and near vision, monocular accommodative facility at near vision, and near point of convergence (break and recovery points). All the athletes were men with a mean age of 24.4 ± 4.8 years. Results No athlete was diagnosed with divergence excess, divergence insufficiency, or basic exophoria. About 13.0% of the athletes have binocular vision dysfunctions related to esophoria (0.9% with esophoria at near vision and 12.1% with esophoria at distance and near vision). About 10.3% have convergence insufficiency and 2.8% were diagnosed with fusional vergence dysfunction. The only accommodation-related parameter analysed was accommodative infacility, and 6.5% of the athletes had this dysfunction. Vertical phoria was present in 3.7% of the athletes. No statistically significant differences were found based on in athletes with respect to ethnicity, position occupied on the field, age, ametropia or laterality. Conclusion The overall prevalence of binocular vision dysfunction in elite soccer players was 36.4%. The most prevalent dysfunctions are related to the presence of esophoria (13.0%). The values found point out the need to include binocular vision assessment protocols in the visual assessment routine for athletes.

Accommodative and binocular vision dysfunctions in a Portuguese clinical population

BackgroundSeveral studies have suggested that accommodative and non-strabismic binocular dysfunctions are commonly encountered in optometric practice. This study aims to verify whether these findings apply to a Portuguese clinical population. MethodsThis study included consecutive nonpresbyopic subjects that came to two Portuguese optometric clinics over a period of six months. A complete visual exam was conducted and included the measurement of visual acuity (VA), refraction, near point of convergence (NPC), distance and near phoria, near and distance fusional vergences, amplitude of accommodation (AA), monocular accommodative facility (MAF), relative accommodation and lag of accommodation. Results156 subjects with a mean age of 24.9 ± 5.3 years (from 18 to 35 years old) participated in the study. Of all subjects, 32 % presented binocular vision and/or accommodative disorders accompanied or not by refractive errors. Moreover, 21.1 % had accommodative disorders, and 10.9 % had a binocular vision dysfunction. Accommodative insufficiency (11.5 %) was the most prevalent disorder, followed by convergence insufficiency (7.1 %) and accommodative infacility (5. 8 %). ConclusionsClinicians should be aware that about one third of the optometric clinical population could have accommodative and/or non-strabismic binocular disorders. Accommodative insufficiency was the most prevalent dysfunction presented in the studied population, followed by accommodative infacility and convergence insufficiency.

Does coexisting accommodative dysfunction impact clinical convergence measures, symptoms and treatment success for symptomatic convergence insufficiency in children?

To determine whether coexisting accommodative dysfunction in children with symptomatic convergence insufficiency (CI) impacts presenting clinical convergence measures, symptoms and treatment success for CI. Secondary data analyses of monocular accommodative amplitude (AA; push-up method), monocular accommodative facility (AF; ±2.00D lens flippers) and symptoms (CI Symptom Survey [CISS]) in children with symptomatic CI from the Convergence Insufficiency Treatment Trial (N=218) and CITT-Attention and Reading Trial (N=302) were conducted. Decreased AA was defined as more than 2D below the minimum expected amplitude for age (15 - ¼ age); those with AA<5D were excluded. Decreased AF was defined as <6 cycles per minute. Mean near point of convergence (NPC), near positive fusional vergence (PFV) and symptoms (CISS) were compared between those with and without accommodative dysfunction using analysis of variance and independent samples t-testing. Logistic regression was used to compare the effect of baseline accommodative function on treatment success [defined using a composite of improvements in: (1) clinical convergence measures and symptoms (NPC, PFV and CISS scores) or (2) solely convergence measures (NPC and PFV)]. Accommodative dysfunction was common in children with symptomatic CI (55% had decreased AA; 34% had decreased AF). NPC was significantly worse in those with decreased AA (mean difference=6.1cm; p<0.001). Mean baseline CISS scores were slightly worse in children with coexisting accommodative dysfunction (decreased AA or AF) (30.2 points) than those with normal accommodation (26.9 points) (mean difference=3.3 points; p<0.001). Neither baseline accommodative function (p≥0.12 for all) nor interaction of baseline accommodative function and treatment (p≥0.50) were related to treatment success based on the two composite outcomes. A coexisting accommodative dysfunction in children with symptomatic CI is associated with worse NPC, but it does not impact the severity of symptoms in a clinically meaningful way. Concurrent accommodative dysfunction does not impact treatment response for CI.

The effect of extended depth of focus contact lenses on the accommodation of presbyopic eyes

Objective: To evaluate the effect of extended depth of focus contact lenses on the accommodation of presbyopic eyes. Methods: It was a double-blind randomized controlled trial. Thirty eyes of 30 emmetropic volunteers (15 males, 15 females) who were staff or family members of Hainan Eye Hospital, aged (49.6±4.5) years, were selected. Non-dominant eyes were fitted with soft contact lenses with an extended depth of field. The subjects and examiners were double-blind. Visual acuities of the subjects were examined at 5 m, 40 cm and 60 cm distance before and after the contact lens wear. Meanwhile, the monocular accommodative amplitude, monocular accommodative facility (±1.00 D), accommodative response, binocular positive/negative relative accommodation and accommodation convergence/accommodation at 40 cm distance were measured. The data were analyzed by paired t test and Wilcoxon signed rank test before and after the contact lens wear, and a P value less than 0.05 was considered statistically significant. Results: Before and after the contact lens wear, the visual acuity at 40 cm was 4.59±0.14 and 4.69±0.10, and the difference was statistically significant (t=4.16, P<0.01). The visual acuity at 60 cm was 4.74±0.10 and 4.74±0.12, and the difference had no statistical significance (t=0.626, P>0.05). The distance visual acuity was 5.00±0.06 and 4.96±0.06, and the difference was statistically significant (t=3.89, P<0.01). The monocular accommodative amplitude was significantly improved from (3.26±0.26) D to (4.00±0.51) D (t=7.59, P<0.01). The monocular accommodative facility was also significantly improved from (2.67±1.60) cyc/min to (3.53±1.87) cyc/min (t=2.17, P<0.05). There was no statistically significant difference in the positive and negative relative accommodation (t=1.90, 0.66; P>0.05). The accommodation convergence/accommodation and adjustment lag had no statistical significance (Z=0.83, 0.11; P>0.05). Conclusion: Wearing contact lenses with an extended depth of field can improve the near vision and accommodation of presbyopes (Chin J Ophthalmol, 2021, 57:292-296).

Feasibility of optical quality analysis system for the objective assessment of accommodation insufficiency: a phase 1 study

PurposeTo assess differences in a new objective metric obtained with a double-pass technique between a group with accommodation insufficiency (AI) and a control group and to explore the diagnostic capabilities of this new tool in comparison to conventional procedures. MethodsRetrospective cross-sectional case-control phase 1 study. Two groups with ages ranging from 8 to 18 years were recruited: AI and control group. The diagnostic criterion of AI was based on monocular accommodative amplitude (AA), 2 D below Hofstetter’s calculation for minimum AA, and monocular accommodative facility (MAF), failing with minus lens and cut-off at ≤ 6 cycles per minute. Accommodative response with a double pass device (HD Analyzer, Visiometrics) was measured, performing an evaluation from +1.00 D to −3.50D (−0.5D steps), offering the width of the profile at 50% (WP) in minutes of arc. ResultsDifferences were found between groups for the AA, MAF and MEM retinoscopy (p < 0.0001, p < 0.001, p = 0.037). The discriminative capacity of MEM retinoscopy for AI diagnosis was significant and the cut-off that maximized the sensitivity and specificity was > 0.5 D. Considering WP 50% in different points, the discriminative AI diagnosis capacities for the points of 2.0 D and 2.50 D were significant (ROC-AUC 0.78; p = 0.03 and p = 0.02). ConclusionsDouble-pass system metric differed between patients with AI and control group, therefore the aim of a Phase I study was achieved. Further steps with higher sample sizes are required to evidence if the system really provides any advantage versus conventional methods in the diagnosis of AI.

The Accommodation Response and Facility between Children and Young Adults

Tonic accommodation decreased with age among children. In young adults, late-onset myopia will develop due to occupational near vision demands. This study aims to investigate the accommodation response and facility between children and young adults, in emmetrope (non-myopic) and myope group. The accommodation response and facility of young adults and children were measured using monocular estimation method (MEM), monocular accommodative facility (MAF) and binocular accommodative facility (BAF) with an exposure of near task for 15 minutes. Near task has significantly increased the lag of accommodation in all groups (p&lt;0.05). However, the accommodation facility was not affected by near work in all groups (p&gt;0.05). Keywords: accommodation response, accommodation facility, myopes, emmetropes. eISSN: 2398-4287© 2020. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning &amp; Surveying, Universiti Teknologi MARA, Malaysia. DOI: https://doi.org/10.21834/ebpj.v5i14.2168