Testing Accommodation in Children

Accommodation disorders are associated with a host of etiologies. Children with accommodative disorders can present with various symptoms including blur, fluctuating vision, eye pain, burning sensation, tired eyes, asthenopia, headaches, fatigue with near work, and excessive rubbing, blinking, or tearing. This chapter provides an overview of accommodation testing on pediatric patients in the clinical setting. The author describes the indications for accommodation testing and provides clinical pearls for testing accommodative function in children. The chapter covers the specific tests, equipment required, and step-by-step procedures for testing accommodative amplitude, accommodative response, and accommodative facility.

The response of the accommodation system to digital and print images

Background: The transition from traditional print medium to a digital medium may affect the accommodative response (AR) because of the differences in the characteristics of the targets viewed.Aim: This study investigated how the accommodation system responded to targets displayed on a tablet computer compared to that on paper.Setting: The study was conducted amongst students at a university in South Africa.Methods: Using a quantitative, cross-sectional study the AR, amplitude of accommodation (AA), and accommodative facility (AF) were assessed with a target on an iPad and a paper-based one on a non-probability sample of 30 university students. Data was analysed using descriptive statistics and Bland Altman plots.Results: The median AR with a tablet was +0.25 dioptre (D) compared to +0.21 D with the paper-based target. This difference was neither statistically nor clinically significant. The median AA with a tablet computer target was 10.59 D and 9.85 D with a paper-based target. While this difference was statistically significant (p = 0.002), Bland Altman analysis revealed comparable measurements with both types of targets. Both Wilcoxon Signed Ranks Test (p = 0.462) and Bland Altman analysis found comparable medians for AF obtained with a target on paper (7.67 cycles per minute [cpm]) and a target on the tablet computer (7.17 cpm) to be comparable.Conclusion: The accuracy, strength and flexibility of accommodation were comparable for tablet computer and paper-based targets.

Virtual Reality-based Vision Therapy Versus OBVAT in the Treatment of Convergence Insufficiency, Accommodative Dysfunction: A Randomized Controlled Trial

Background: Virtual 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.Methods: The 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.Results: In 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).Conclusion: Virtual 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 registration: This study was registered at the Chinese Clinical Trials Registry on 16/04/2019 (identifier: ChiCTR1900022556).

Investigation of the Relationship Between Subjective Symptoms of Visual Fatigue and Visual Functions

PurposeTo investigate whether the severity of symptoms of visual fatigue might be associated with clinical visual measures and basic visual functions, such as accommodation, vergence, and contrast sensitivity.MethodsIn this study, 104 students were recruited (25 males, 79 females, Age 23.4 ± 2.5) for this study. Those with high myopia, strabismus, anisometropia, eye disease or history of ophthalmological surgery were excluded. The included subjects completed a questionnaire that assesses the severity of visual fatigue. Then, binocular accommodative facility, vergence facility and contrast sensitivity using a quick contrast sensitivity function approach were measured in a random sequence. Next, the correlations between each symptom of visual fatigue in the questionnaire and accommodative facility, vergence facility and contrast sensitivity were examined.ResultsFactor analysis indicated that visual fatigue, as captured by the scores of a subset of the questionnaire items, could be strongly related to binocular accommodative facility and binocular contrast sensitivity, but not to vergence facility. We also found that binocular accommodative facility and contrast sensitivity at high spatial frequencies are related.ConclusionOur findings suggest that visual fatigue is related to the ability of human observers to encode visual details through their binocular vision.

Smartphone induced eye strain in young and healthy individuals

Background: Usage of digital devices has become one's basic need. Digital eye strain is repeatedly noticed sequelae in optometry practice. Objectives: This study aims to estimate the different aspects of eye strain. Methodology: Altogether, 55 students with a mean age of 21.25 years, vision (≥6/9) were enrolled. A survey related to common asthenopic (eyestrain) symptoms was carried before and after reading an extract from a novel. Accommodative facility and non-invasive first tear breakup (NTBUT) time were measured before and after the reading. The viewing distance to a smartphone was measured every 20 minute. Results: The total eye strain symptom score was significantly greater post-experiment (score = 7.07±2.84) than pre-experiment (score = 1.54±1.60, p < 0.001). Symptoms of tired eyes, sore eyes, and sleepy eyes increased significantly after 60 min of a smartphone use (p < 0.05). The mean viewing distance while using a smartphone over 60 min was 30.15 ± 3.29 cm. There was a significant correlation between change in total symptom score and change in viewing distance (r = ˗0.301, p = 0.026). The symptom that correlated with a change in viewing distance was ‘sore eyes’ (r = ˗0.382, p = 0.04) and sleepy eyes (r= ˗0.363, p=0.06). There was a significant decrease in monocular and binocular accommodative facilities and NTBUT after 60 min of reading. Conclusion: Closer viewing distance and eyestrain symptoms are obvious after a smartphone reading. Prolonged use of smartphones appears to have important implications for accommodative function, causing ocular symptoms having an impact on quality of life.

Changes in accommodative function following small-incision lenticule extraction for high myopia

Purpose To examine whether the amplitude of accommodation, the accommodative response, and the accommodative facility is affected and correlated with changes in higher-order aberrations for patients with high myopia surgically treated with small-incision lenticule extraction (SMILE). Methods 35 highly myopic eyes (myopic spherical equivalent of at least 6 diopters) of 35 patients treated with SMILE were included. Assessments were made before and 3 months after surgery. Donders push-up-method was used to measure the amplitude of accommodation. The accommodative response was assessed using an open-field autorefractor”Grand Seiko WAM-5500” (Grand Seiko Co. Ltd., Hiroshima, Japan) in combination with a Badal optometer and stimuli of accommodation at 0.0, 0.5, 1.25, 2.0, 3.0, and 4.0 D, respectively. Accommodative facility was measured at 40 cm with ±2,00D flipper lenses. All measurements of accommodation were performed monocularly with the refractive error corrected with soft contact lenses. Results The amplitude of accommodation did not change statistically significantly (mean difference -0.24 D (SD 0.98), 95% CI of mean difference -0.58 D to 0.11 D, paired-sample t(34) = -1.39; P = 0.17). The accommodative responses at 0.0, 0.5, 1.25, 2.0, 3.0, and 4.0 D did not statistically significantly change either (F(6,29) = 1.15; P = .36). Finally, the accommodative facility was also unchanged with a mean difference of 1.11 cycles per minute (SD 5.11, 95% CI of mean difference -0.64 to 2.87, paired-sample t(34) = 1.29; P = 0.21). No clinically significant associations between changes in accommodation and higher-order aberrations were found. Conclusions SMILE does not alter the amplitude of accommodation, the accommodative response, nor the accommodative facility for highly myopic patients, and the surgically induced corneal higher-order aberrations do not affect the accommodative function.