Myopia--a treatable "disease"?

The authors cite various information and misinformation regarding proposed treatments (atropinization, contact lenses, orthokeratology, wearing glasses, not wearing glasses) for the progression of myopia. They conclude that there is insufficient evidence to support the more vigorous approaches to treatment of myopia, and provide some useful explantations for patients and their parents who question the ophthalmologist's decision to treat conservatively.

Ectopia lentis et pupillae

Two brothers had ectopia lentis et pupillae, an autosomal recessive disorder. Ascertainment of the brothers occurred through an unaffected sister, who sought genetic advice concerning possible risk for the disorder in her future children. Although the clinical features and the genetic aspects of ectopia lentis et pupillae are well documented in the older ophthalmologic literature, this entity has received relatively little attention recently in major reference texts.

Dislocation of the hip in birth defects

Several heritable disorders--although rare--are reviewed that are directly or indirectly related to dislocation of the hip. With the ever increasing list of clinical syndromes and our growing understanding of genetics, the physician who first sees these patients should broaden his views to identify these conditions and establish the diagnosis. The effectiveness of treatment often depends upon such knowledge.

A monozygotic cotwin control study of a treatment for myopia

Myopia is the world's most common cause of defective vision. The role of controlled accommodation on the progress of myopia is unsettled. This cotwin control study is designed to provide a careful appraisal of the effectiveness of a clinically acceptable method of controlling accommodation. There are no previous reports of similar prospective studies among MZ twins. Expansion of such studies would be aided by collaboration among interested investigators.

Genetic factors in myopia

A school population has been screened to locate same-sexed twins with myopia and also to compare intelligence test performance of myopic and nonmyopic individuals. Augmentation of the twin data by a survey of the world literature has led to the identification of a total of 106 MZ twin pairs, 100 of them concordant for myopia, as well as 41 DZ pairs, 12 concordant. Myopic students score eight points higher on IQ tests than nonmyopes, the entire bell shaped distribution curve being shifted to a higher range. The intellectual gain precedes in time the development of nearsightedness.

The Stickler syndrome presenting as a dominantly inherited cleft palate and blindness

The Stickler syndrome is a newly recognized, but probably relatively frequent inherited generalized connective tissue disorder involving skeleton, eye, and oro-facial structures. A family with three affected generations is discussed. Severe myopia leading to blindness, cleft palate, or subnucous cleft, Pierre Robin anomaly, premature degenerative arthritis, or a family history of any of these indicates further evaluation.

Influence of the myopia gene on brain development

Evaluation of the performance of 17-18-year-old high school students on standard intelligence tests confirms previous reports that nearsighted persons consistently achieve scores approximately eight I.O. points higher than non-myopes. Comparison of tests administered to the same students 10 years earlier suggests that the intellectual gain precedes the development of nearsightedness. Since there is convincing evidence from genetic studies that myopia is an inherited condition, probably transmitted as a recessive characteristic, it is concluded that the myopia gene has a stimulant action on the brain in addition to its effect on the eye. The high frequency of myopia in urbanized societies is explained in terms of an evolutionary adjustment, myopes probably having a survival advantage under conditions of industrialization.

Variable expression of Marfan syndrome in monozygotic twins

A pair of monzygotic twins with the Marfan syndrome with variable expression is presented. One of the twins, in addition to more severe musculoskeletal and ocular manifestations, had coarctation of the aorta as the cardiovascular manifestation of this symdrome. Analysis of red cell antigens, serum proteins and dermatoglyphic examination suggests a high probability of monozygosity. Accordingly, the variation in expression of this autosomal dominant disorder between the twins is most likely due to the modifying influences of environmental factors. Also noteworthy is the fact that the resected coarctation tissue demonstrated the histopathologic changes characteristic of cystic medial necrosis, and thus served as an additional piece of evidence supporting the diagnosis of the Marfan syndrome. This was of particular importance in view of the absence of any family history of this syndrome and the absence of ectopia lentis or the more typical cardiovascular manifestations in either twin.

Inuit myopia: an environmentally induced "epidemic"?

Among Inuit less than 30 years old the prevalence of myopia is far in excess of that of their elders. This is especially true for females. There seems to be little, if any, genetic contribution to this "epidemic" of myopia in the young. The age and sex distribution indicates the likelihood of an environmental factor, probably cultural, being responsible for the current pattern. Other data implicate school attendance as a possible etiologic factor.

Evidence of recessive inheritance of myopia

Data are presented on the family distribution of nearsightedness, including the frequency of the disorder in the children of two myopes. The previous literature is reviewed, embracing several quantitative family or population studies in addition to extensive pedigree material. It is concluded that there is substantial evidence that recessive inheritance is the principal mechanism of transmission, and that most instances of myopia probably fall into that category.

Inherited hyaloideoretinopathy and skeletal dysplasia

Twenty-one patients from five families displaying the ocular defects of dominantly inherited hyaloideoretinopathy as originally described by Wagner were surveyed radiographically for skeletal defects. A mild generalized epiphyseal dysplasia was found in twenty. A comparison of the skeletal dysplasia associated with arthro-ophthalmopathy and that found in families with Wagner's disease reveals more similarities than differences. It is concluded that Wagner's disease is a dominantly inherited syndrome of ocular defects that includes myopia, vitreous syneresis with membranes, and radial perivascular chorioretinal degeneration. It is associated with radiographically demonstrated generalized epiphyseal dysplasia that is manifested clinically by flattening of the mid-face and palatoschisis.

Stickler's syndrome (hereditary progressive arthro-ophthalmopathy)

The clinical features of Stickler's syndrome are described in two families with a total of 22 affected members and compared with those of the three previously reported families. Progressive joint degeneration (85%), myopia (83%) and retinal detachment (61%) are the most frequent manifestations. Cleft palate (28%), micrognathia (17%) and sensorineural hearing loss (9%) are also liable to occur in affected individuals. Inheritance is autosomal dominant with virtually complete penetrance. Genetic counselling is extremely important and relatively straightforward since most of the findings are manifest in the first two decades of life and represent severe incapacities to the affected families. All six of the affected individuals tested had increased urinary hydroxyproline excretion, a feature that may lead to earlier postnatal and possibly prenatal diagnosis.

Hyalo-retinopathy in the clefting syndrome

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