Prevention of myopia by partial correction of hyperopia: a twins study

Models of myopia: the effect of accommodation, lenses and atropine

BACKGROUND

Two quantitative models for myopia have been proposed and used for myopic intervention, one derived from feedback theory, and the other from physiological and mechanical considerations. This paper shows that they both predict the same results indicating that they are valid and reliable. These models are the only ones that can make predictions about the effect of atropine and lenses on myopia, explain multiple observations heretofore unexplained and offer possible interventions.

OBJECTIVE

Using their predictive power we test the models by calculating and comparing the effect of accommodation, lenses or atropine. The models offer a rationale that makes atropine equivalent to a positive lens for purposes of refractive development.

METHODS

This report includes thought experiments, actual experiments and trials, as well as an analysis of clinical data and integrates and tests results from all of them for far-reaching conclusions.

RESULTS

Both models accurately predict the same myopia progression caused by near work. These models are simple but powerful enough to suggest what treatments are indicated. Interventions for prevention and control of myopia are evaluated analytically, in particular atropine and optical treatments, such as positive lenses and under correction.

CONCLUSION

Optical treatments have enormous potential; atropine is of questionable value since there are ways to get the same or superior effect with lenses of power calculated as described here.

The equations of ametropia: Predicting myopia

Why myopia develops, why it is reaching epidemic proportions and what is its cause are questions that puzzle many people. There is an answer to these questions and it is a simple one. This paper makes the connection between ametropic and in particular myopic development and theory to come with a summary of what we know about myopia and its governing equation. Key experiments, involving myopia and the effect of lenses in humans and animals have been done with unmistakable results. The observed effect of lenses implies a feedback mechanism. Feedback theory explains those results with mathematical precision. Disruption of emmetropization, is the mechanism behind ametropia and particularly myopia. Feedback theory for emmetropization was derived by observation of the input and output of the emmetropization feedback system in many patients. We show that it has the same equation as it is derived here independently from simple homeostasis principles. Classical observations and recent clinical studies have shown the association of many variables with myopia. They include near work, atropine, lenses, blur and outdoors versus indoors activities. We propose that human refractive development is controlled by homeostasis and based on that alone we derive the equation for the calculation of refraction for any patient and the effect of lenses. We provide software to calculate the refraction of any individual at any time. The editor of this journal makes the following statement: "This manuscript is intended for scientific discussion rather than clinical application. The present work does not intend to promote clinical under correction or no correction of myopia. Instead, clinicians should follow current clinical myopia management guidelines."

The cause of myopia development and progression: Theory, evidence, and treatment

I review the key findings and our current knowledge of the cause of myopia, making the connections among the reliable observations on myopia development and theory to arrive at a summary of what we know about myopia, the proposed prevailing theory, and applicable action. Myopia is reaching epidemic proportions. It is estimated that half of the world's population will be myopic by 2050 unless new strategies to fight myopia are developed. Our high-level mathematical description of myopia is translated into clinical applications involving effective treatment and prevention. A regulating mechanism controlling the refraction of the eye is intimately related to myopia. The approach at hand is to review our knowledge about emmetropization, connecting myopia and emmetropization feedback theory to unveil the cause of myopia. Many observations discussed here test the validity of feedback theory positively. The cause of human myopia fits perfectly with the idea that emmetropization, in particular its feedback theory implementation, is the controlling mechanism behind myopia. They include near work, atropine, lenses, defocus, and outdoor versus indoor activities. The key findings in myopia research point the same way: myopia is the result of corrective lenses interfering with emmetropization. We have enough knowledge to answer the question of whether myopia can be reversed or prevented. There is no need to have mathematical skills to apply theory to real cases. It is enough to know the predictions of the feedback theory of emmetropization.

The relationship between education levels, lifestyle, and religion regarding the prevalence of myopia in Israel

BACKGROUND

The ultra-Orthodox Jewish community has a unique lifestyle including minimal outdoor activity and intense, prolonged nearby work, beginning at a very young age. Their prevalence of myopia is extremely high. This paper provides a unique insight into the attitudes of this community towards myopia.

METHODS

Ultra-Orthodox Jewish parents of children who came to the pediatric ophthalmology clinic in one tertiary care and two community centers in ultra-Orthodox-oriented cities were given a questionnaire. Demographic information, along with myopia prevalence in the family, was gathered. In addition, their attitudes and common knowledge regarding myopia were investigated.

RESULTS

161 questioners were collected, mostly completed by mothers (n = 110, 68%). The average number of children per family was 6 (range 1-16). In 148 families (92%) at least one of the parents has myopia. The average parent refraction was - 4.5 diopters (range - 0.5 to 15 diopters). Out of 935 children, 410 (44%) wore glasses. Twelve parents (7%) believe that myopia is a disease and 94 (58%) reported that they are concerned because their child wears glasses. Twenty-four (15%) believe that glasses are a sign of a high education level. Regarding treating myopia progression, 144 (89%) think that myopia progression should be treated, but only 36 (22%) are aware of the available treatments for it.

CONCLUSION

This study examines an insular community with a very high incidence of myopia. In this community most parents think that myopia progression should be treated but most of them are unaware of the currently available treatments.

Spontaneous resolution of a traumatic cataract in a patient with an open-globe ocular injury: a case report

Background

We report a case of spontaneous resolution of a traumatic cataract in a patient with an open-globe ocular injury. This case highlights the importance of conservative management in these types of cases, as excellent visual outcome is possible without invasive surgical intervention.

Case presentation

A 13-year-old boy presented with a corneal laceration in the left eye caused by a neuter pen. He underwent emergency repair of the corneal laceration under general anesthesia, and at 3 days post-op, a dense posterior cortical cataract was observed. Based on the patient’s age and normal visual development, in addition to preserving accommodative potential, the patient received conservative management and follow-up. Interestingly, the cataract spontaneously resolved over the following 9 months and the corrected distance visual acuity in the injured eye was restored from finger counting at 50 cm, to 20/25 + 3.

Conclusions

To optimize treatment in pediatric traumatic cataract, several critical factors such as age, visual development and the preservation of accommodative potential, need to be comprehensively considered. Conservative management with lens preservation is important to consider in young, traumatic cataract patients where invasive surgical intervention may not be required.