Family distribution of concomitant squint in Greece.

Abstract

SUMMARY From a study of a large number of brothers and sisters suffering from concomitant squint, the following data were obtained: (1) 42-9 % of the patients showed congenital strabismus.(2) In 96 5 % of the sibs strabismus was of the same type. (3) The presence of a significant refractive error occurred in 82-8 % of the patients. (4) In all twins strabismus appeared at the same age in both twins, and the squint and the refractive error were of the same type. (5) The distance of the patients' homes from Athens had no effect on either (a) the time intervening between the onset of squint and the first visit to the eye specialist, or (b) the effectiveness of treatment.Investigations to determine the genetic element in strabismus and the type of heredity involved have been the subject of numerous studies (Frangois, 1961;Richter, 1967), although no definite conclusions have so far been reached. The present study does not aspire to offer a solution to this complex question and confines itself to an examination of familial cases of squint with the purpose of extracting data concerning: (1) The age of onset of squint; (2) the type of squint; (3) the frequency of the existence of a significant refractive error; (4) the incidence of amblyopia; and (5) the geographical distribution of squint in relation to the place of residence and its influence on (a) the period of time intervening between the onset of strabismus and the first ophthalmic consultation, and (b) the efficacy of the treatment. Material and methodOur material, drawn from the archives of the Orthoptic Department, which contains about 12 000 patients, consists of 170 families containing 345 affected first degree relatives (brothers and sisters) who came under the observation of the Athens University Eye Clinic in the course of the last eight years. Cases of paretic strabismus or neurological syndromes were excluded from our study.Information obtained from relatives suggested that the incidence of a family history of squint was 55 %. As we did not consider these data absolutely Part of this paper was presented at the meeting of the International Geographical Society in Edinburgh, 1975. Address for reprints: Dr E. Chimonidou, National Ophthalmological Center of Athens, 170 Messogion Avenue, Cholargos, Athens, Greece. reliable, we have included in our group of patients only those that were under observation and treatment for strabismus for a considerable length of time. Our patients included five pairs of twins (10 persons), one pair being uniovular.The patients were subjected to examination for the following data: (1) Personal and family history; (2) visual acuity, and refractive error determined after the instillation of atropine for 3 days; (3) type and angle of squint; (4) state of binocular vision; (5) fundus of the eye and type of fixation; and (6) place of residence.Furthermore, patients were treated appropriately in each instance by: (1) Prescription of glasses; (2) occlusion; (3) orthoptic treatment; (4) surgical treatment. Results AGE OF ONSET OF S...

Pattern of squint presentations in children in a tertiary institution in Western Nigeria

“…This could be attributed to the impact of squint on the physical appearance of a female child with attendant psychological effect in future or the small sample size. Esotropia was the commonest type of squint like in many other similar reports 1,11,12 being the most common childhood squint. Though genetic predisposition has been associated with squint development, we didn't find much evidence of this in this study as only one of the patients was a twin and the first twin did not have squint.…”

Genetic and environmental contributions to strabismus and phoria: Evidence from twins

“…It has long been known that eye misalignment tends to cluster in families (Jones, 1886), and recent studies have confirmed this fact for both phoria and strabismus (Abrahamsson, Magnusson & Sjostrand, 1999; Chimonidou, Palimeris, Koliopoulos & Velissaropoulos, 1977; Francois, 1961; Mash, Hegmann & Spivey, 1975; Paul & Hardage, 1994; Richter, 1967; Schlossman & Priestley, 1952; von Rotth, 1937). However, either genes or environment can contribute to resemblance among family members; therefore, familial clustering does not clarify etiology.…”

“…A large twin strabismus literature has accumulated (Chimonidou et al, 1977; de Decker & Feuerhake, 1978; DeVries & Houtman, 1979; Francois, 1961; Knobloch, Leavenworth, Bouchard & Eckert, 1985; Kondo, Mori & Adachi, 1975; Kvapilikova, 1969; Lang, 1990; Matsuo, Hayashi, Fujiwara, Yamane & Ohtsuki H, 2002; Orlebeke & Koole, 1999; Paul & Hardage, 1994; Podgor, Remaley & Chew, 1996; Reynolds & Wackerhagen, 1986; Richter, 1967; Schlossman & Priestley, 1952; Waardenburg, 1961; Weekers, Moureau, Hacourt & Andre, 1956; Wei, 1987). However, quantitative estimates of genetic and environmental influence have not yet been derived from these data, nor has this literature been evaluated in light of modern standards for twin research (Neale & Cardon, 1992; Rijsdijk & Sham, 2002; Sullivan, Kendler & Neale, 2003).…”

A strabismus susceptibility locus on chromosome 7p

“…These heritability values are likely to be underestimates for the following three reasons: (i) Ϸ15-20% of strabismus is clearly associated with nonocular disorders, including low birth weight and global CNS defects (12), which are included in the population incidence in most studies; (ii) there is incomplete detection of esophorias and exophorias, microtropias, and the monofixation syndrome (reduced stereoacuity to worse than 60 s of arc), all of which occur at higher frequencies in families of strabismics and probably represent the incompletely penetrant phenotype (13,14); and (iii) similar or identical subtypes of strabismus tend to cluster within a single family and between monozygotic twins and this would lead to greater heritability estimates if strabismus subtypes were considered separately (15). As an example of the second point, Scott et al (14) found that the monofixation syndrome was present in 7.7% of first degree relatives of patients with infantile esotropia, compared with a prevalence of 1% in the general population.…”