New pediatric risk factors for amblyopia: strabismic versus refractive

Quantitative evaluation of anisometropic amblyopia treatment efficacy by coupling multiple visual functions via CRITIC algorithm

BACKGROUND

The evaluation of amblyopia treatment efficacy is essential for amblyopia prevention, control, and rehabilitation.

METHODS

To evaluate the amblyopia treatment efficacy more precisely and quantitatively, this study recorded four visual function examination results, i.e., visual acuity, binocular rivalry balance point, perceptual eye position, and stereopsis before and after amblyopia treatment.

RESULTS

We found that all these four results had a significant difference between before and after treatment, and the relationship between visual acuity improvement and the difference of BRBP, PEP, and stereoacuity cannot show a fitting correlation regarding the widely used index of visual acuity as the standard of treatment efficacy. By using the Criteria Importance Through Inter-criteria Correlation (CRITIC) method, a more comprehensive and quantitative index by coupling the selected four indexes with objective weights was obtained for further training efficacy representation, and the validation dataset also showed a good performance.

CONCLUSIONS

This study proved that our proposed coupling method based on different visual function examination results via the CRITIC algorithm is a potential means to quantify the amblyopia treatment efficacy.

Amblyopia screening effectiveness at 3-4 years old: a cohort study

Objective

To study the effectiveness of amblyopia screening at ages 3-4.

Methods and Analysis

From a population with no previous screening, a cohort of 2300 children with 3-4 years old attending school (91% of children this age attend school in Portugal), were submitted to a complete ophthalmological evaluation. Amblyopia was diagnosed, treated and followed. Amblyopia prevalence, treatment effectiveness, absolute risk reduction (ARR), number needed to screen (NNS) and relative risk reduction (RRR) were estimated.

Results

Past/present history of amblyopia was higher than 3.1%-4.2%, depending on amblyopia definition normatives. Screening at age 3-4, had estimated ARR=2.09% (95% CI 1.50% to 2.68%) with a reduced risk of amblyopia in adulthood of 87% (RRR). NNS was 47.8 (95% CI 37.3 to 66.7). Treatment effectiveness of new diagnosis was 88% (83% if we include children already followed). 91% of new amblyopia diagnoses were refractive (of which 100% surpassed amblyopia Multi-Ethnic Pediatric Eye Disease Study criteria after treatment), while most strabismic amblyopias were already treated or undertreatment. Only 30% of children with refractive amblyopia risk factors that were not followed by an ophthalmologist, ended up having amblyopia at age 3-4. Eye patch was needed equally in new-diagnosis versus treated-earlier refractive amblyopia.

Conclusions

Screening amblyopia in a whole-population setting at age 3-4 is highly effective. For each 48 children screened at age 3-4, one amblyopia is estimated to be prevented in the future (NNS). Screening earlier may lead to overdiagnosis and overtreatments: Treating all new diagnosis before age 3-4 would have a maximal difference in ARR of 0.3%, with the possible burden of as much as 70% children being unnecessary treated before age 3-4.Involving primary care, with policies for timely referral of suspicious/high-risk preverbal children, plus whole screening at age 3-4 seems a rational/effective way of controlling amblyopia.

Characterization, passive and active treatment in strabismic amblyopia: a narrative review

Strabismic amblyopia is characterized by a distorted spatial perception. In this condition, the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding, deficits in the accommodative response, contrast sensitivity, and ocular motility abilities. The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity. Passive treatments such as occlusion, optical and/or pharmacological penalization, and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia. Recent researches have proved new pharmacological options to improve and maintain visual acuity after occlusion treatment in strabismic amblyopia. Likewise, the active vision therapy, in the last years, is becoming a very relevant therapeutic option in combination with passive treatments, especially during and after monocular therapy, in the attempt of recovering the imbalanced binocular vision.