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

PURPOSE: To determine whether coexisting accommodative dysfunction in children with symptomatic convergence insufficiency (CI) impacts presenting clinical convergence measures, symptoms and treatment success for CI. METHODS: Secondary data analyses of monocular accommodative amplitude (AA; push-up method), monocular accommodative facility (AF; ±2.00 D 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 - » age); those with AA < 5 D 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)]. RESULTS: 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 = 6.1 cm; 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. CONCLUSIONS: 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.

Near-point Findings in Children with Autism Spectrum Disorder and in Typical Peers.

SIGNIFICANCE: Clinicians can better diagnose and manage vision problems of autism spectrum disorder (ASD) children by establishing a standard of care for this population. Results also reinforce the importance of a comprehensive binocular vision evaluation in all patients with ASD. PURPOSE: The purposes of this study were to compare near-point and ocular motility test findings in ASD children and typically developing (TD) peers and to compare findings among ASD children by level of verbal communication. METHODS: Sixty-one children and adolescents (ASD, 34; TD, 27) aged 9 to 17 years completed an eye examination protocol including tests of distance and near phoria, near point of convergence, near fusional convergence and divergence, accommodative response, and Northeastern State University College of Optometry oculomotor testing. Testing was completed through refractive correction. Parents of ASD children provided information regarding subjects' verbal communication level (nonverbal, uses short words, verbal). RESULTS: Distance phoria did not differ significantly between groups. Near phoria of ASD subjects was more exophoric (difference, 2.8 prism diopters). Mean near point of convergence break and recovery were 7.0 and 8.02 cm, respectively, in ASD subjects and 2.19 and 3.99 cm in TD subjects. Near fusional divergence and convergence showed no significant difference. Autism spectrum disorder subjects had significantly poorer stereoacuity (P < .0001) and, on Northeastern State University College of Optometry Oculomotor Testing, reduced fixation, poorer accuracy and stamina/ability, and increased head and body movement. Monocular estimation method retinoscopy results did not differ significantly between ASD and TD subjects. No significant differences in phoria, near point of convergence, and near fusional divergence or convergence were observed between ASD subgroups (nonverbal, uses short words, verbal). CONCLUSIONS: Autism spectrum disorder children are more likely to show receded near point of convergence, poor fixation, inaccurate saccades, erratic pursuits, and exophoric posture. These differences occur, regardless of reported verbal communication level.

Effectiveness of vergence/accommodative therapy for accommodative dysfunction in children with convergence insufficiency.

PURPOSE: To determine the effectiveness of office-based vergence/accommodative therapy for improving accommodative amplitude and accommodative facility in children with symptomatic convergence insufficiency and accommodative dysfunction. METHODS: We report changes in accommodative function following therapy among participants in the Convergence Insufficiency Treatment Trial - Attention and Reading Trial with decreased accommodative amplitude (115 participants in vergence/accommodative therapy; 65 in placebo therapy) or decreased accommodative facility (71 participants in vergence/accommodative therapy; 37 in placebo therapy) at baseline. The primary analysis compared mean change in amplitude and facility between the vergence/accommodative and placebo therapy groups using analyses of variance models after 4, 8, 12 and 16 weeks of treatment. The proportions of participants with normal amplitude and facility at each time point were calculated. The average rate of change in amplitude and facility from baseline to week 4, and from weeks 4 to 16, were determined in the vergence/accommodative therapy group. RESULTS: From baseline to 16 weeks, the mean improvement in amplitude was 8.6 dioptres (D) and 5.2 D in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 3.5 D, 95% confidence interval (CI): 1.5 to 5.5 D; p = 0.01). The mean improvement in facility was 13.5 cycles per minute (cpm) and 7.6 cpm in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 5.8 cpm, 95% CI: 3.8 to 7.9 cpm; p < 0.0001). Significantly greater proportions of participants treated with vergence/accommodative therapy achieved a normal amplitude (69% vs. 32%, difference = 37%, 95% CI: 22 to 51%; p < 0.0001) and facility (85% vs. 49%, difference = 36%, 95% CI: 18 to 55%; p < 0.0001) than those who received placebo therapy. In the vergence/accommodative therapy group, amplitude increased at an average rate of 1.5 D per week during the first 4 weeks (p < 0.0001), then slowed to 0.2 D per week (p = 0.002) from weeks 4 to 16. Similarly, facility increased at an average rate of 1.5 cpm per week during the first 4 weeks (p < 0.0001), then slowed to 0.6 cpm per week from weeks 4 to 16 (p < 0.0001). CONCLUSION: Office-based vergence/accommodative therapy is effective for improving accommodative function in children with symptomatic convergence insufficiency and coexisting accommodative dysfunction.

Optimal dioptric value of near addition lenses intended to slow myopic progression.

PURPOSE: The purpose of this study was to determine the optimal power value of near addition lenses, which would create the least error in accommodative and vergence responses. METHODS: We evaluated accommodative response, phoria, and fixation disparity when the subject viewed through various addition lenses at three working distances for 30 young adults (11 emmetropic, 17 myopic, and 2 hyperopic). Accommodative response was determined with a Canon R-1 infrared optometer under binocular viewing conditions, phoria was determined by the alternating cover test with prism neutralization, and fixation disparity was measured with a Sheedy disparometer. RESULTS: We found that the optimal powers of near addition lenses for the young adult subjects associated with zero retinal defocus were +0.92 D, +1.04 D, and +1.28 D at three viewing distances, 50 cm, 40 cm, and 30 cm, respectively. The optimal powers associated with -3 prism diopters (Delta) near phoria were +0.58 D, +0.35 D, and +0.20 D at the three distances, 50 cm, 40 cm, and 30 cm, respectively. In addition, we found high correlations between the initial accommodative error and the optimal power of the near addition lenses and between the initial near phoria and the optimal power of the near addition lenses. CONCLUSIONS: The results suggest that when the effects of near addition lenses on the accommodative and vergence systems are both considered, the optimal dioptric power of the near addition lens is in a range between +0.20 D and +1.28 D for the three viewing distances. Using progressive lenses to delay the progression of myopia may have promising results if each subject's prescription is customized based on establishing a balance between the accommodative and vergence systems. Formulas derived from this study provide a basis for such considerations.

Changes in accommodative and vergence responses when viewing through near addition lenses.

It has been proposed that near addition lenses reduce the lag of accommodation and may slow myopia progression. In this study, we investigated the differences in accommodative response and near phoria in subjects with and without near addition lenses. Fourteen subjects (7 emmetropic and 7 myopic) participated in the study. Monocular and binocular accommodative responses to a target at 40 cm were measured with and without +2.00 diopter (D) lenses using a Canon R-1 optometer (Canon Europe N.V., Amsterdam, The Netherlands). Near dissociated phoria was measured using 3 testing methods: Maddox rod, cover test, and Von Graefe technique. The differences in accommodative response and near phoria between the 2 viewing conditions with and without the near addition lens were significant (P < 0.0001). No significant differences were revealed in accommodative response and near phoria between refractive error groups. The average accommodative responses of all subjects were 2.03 +/- 0.06 (SE) D (without +2.00 D lens) and 0.60 +/- 0.07 D (with +2.00 D lens) under monocular viewing conditions and 2.11 +/- 0.06 D (without +2.00 D lenses) and 0.77 +/- 0.07 D (with +2.00 D lenses) under binocular viewing conditions. The average near phorias of all subjects were -2.08 +/- 0.69 prism diopters (PD, without +2.00 D lenses) and -7.90 +/- 0.68 PD (with +2.00 D lenses). We discuss the effect of near addition lenses on the defocus of the retinal image, accommodative response, and near phoria. In addition, we propose that the observed difference between binocular and monocular accommodation, when viewing through near addition lenses, is caused by an increased vergence accommodation.