HYPERTELORISM - NOSOLOGIC ANALYSIS OF 90 PATIENTS

The word hypertelorism is used to describe increased interorbital dist ance, a condition that is causally and pathogenically heterogeneous. B ecause not all wide-set eyes are the same, accurate terminology and no sology are critical to understanding and management. Orbital hypertelo rism signifies an increased distance between both medial sides and lat eral sides of the orbits. Interorbital hypertelorism denotes increased distance only between the inner orbital walls. In this retrospective analysis of 90 patients with hypertelorism, the most common cause was frontonasal malformation (n = 30), a heterogeneous category of nonfami lial disorders including a newly described subgroup, rugose frontonasa l malformation. The second most common cause was craniofrontonasal dys plasia (n = 18), a genetic syndrome comprising coronal synostosis, fro ntonasal anomalies, ''frizzy'' hair, narrow/sloping shoulder girdle de formity, and longitudinal ridging of nails in association with various truncal and extremity anomalies. Paramedian craniofacial cleft(s) (n = 10) and (sincipital) encephalocele (n = 6) were infrequent causes of hypertelorism. The fifth, miscellaneous category comprised well-defin ed, mostly chromosomal and syndromic disorders (n = 26). Patients in t he various diagnostic categories were designated as having either orbi tal or interorbital hypertelorism. Hypertelorism also was graded as ei ther first, second, or third degree based on deviation from age- and g ender-matched normative data. The etiology and type of hypertelorism i nfluence the selection of operative procedure, whereas the grade of se verity indicates the need for surgical correction.