Biglan A W, Davis J S, Cheng K P, Pettapiece M C
Department of Ophthalmology, Children's Hospital of Pittsburgh, PA, USA.
J Pediatr Ophthalmol Strabismus. 1996 Mar-Apr;33(2):79-84. doi: 10.3928/0191-3913-19960301-04.
Exotropia is uncommon in healthy children between 6 months and 1 year old.
The charts of patients treated in our practice between January 1980 and August 1994 were reviewed for a diagnosis of infantile exotropia. All of them had an exodeviation during the first year of life. Children with neurologic defects, prematurity, trauma, craniofacial syndromes, or orbital abnormalities or ocular defects that would reduce vision were eliminated.
Sixty-six healthy patients with normal eyes had an exodeviation of 15 prism diopters (delta) or more that persisted through the first year of life. Fifty-four were eliminated because the diagnosis had not been confirmed by a pediatric ophthalmologist before they were 1 year old or they had not been followed for more than 4 years. The 12 remaining patients were followed for at least 4 years (mean, 7.9 years). The mean age at the first examination was 7.8 months (range, 4 to 12 months). On early evaluation, exotropia was intermittent in four and constant in eight. Three had amblyopia. Ten required surgical correction. Exotropia was corrected with one operation in six patients; four required additional procedures, mostly to correct oblique muscle overaction and dissociated vertical deviation (DVD). At the most recent visit, all 12 patients had equal visual acuity in both eyes and satisfactory ocular alignment. Five had fusion at distance and near, but only two had stereo acuity of 100 seconds of arc or better.
Infantile exotropia is rare. But, like patients with infantile esotropia, those with exotropia can be expected to have good visual acuity but unstable ocular alignment. Also, as with early-onset esotropia, although surgical intervention is usually required, high levels of binocular function develop in some patients with exotropia. Oblique muscle overaction and DVD are common, often becoming manifest by the first year of age. Unlike infantile esotropia, nystagmus is rare.
外斜视在6个月至1岁的健康儿童中并不常见。
回顾了1980年1月至1994年8月在我们诊所接受治疗的患者病历，以诊断婴儿型外斜视。他们在出生后的第一年内均有外斜视。患有神经缺陷、早产、创伤、颅面综合征、眼眶异常或会降低视力的眼部缺陷的儿童被排除。
66名眼睛正常的健康患者有15棱镜度（Δ）或更大的外斜视，且持续至出生后的第一年。54名患者被排除，原因是在1岁之前未得到小儿眼科医生的确诊，或者随访时间不足4年。其余12名患者至少随访了4年（平均7.9年）。首次检查时的平均年龄为7.8个月（范围4至12个月）。早期评估时，4例为间歇性外斜视，8例为恒定性外斜视。3例有弱视。10例需要手术矫正。6例患者通过一次手术矫正了外斜视；4例需要额外的手术，主要是矫正斜肌亢进和分离性垂直偏斜（DVD）。在最近一次随访时，所有12例患者双眼视力均相等，眼位矫正满意。5例患者在远距离和近距离均有融合，但只有2例立体视锐度达到或优于100角秒。
婴儿型外斜视很少见。但是，与婴儿型内斜视患者一样，外斜视患者有望拥有良好的视力，但眼位不稳定。此外，与早发性内斜视一样，尽管通常需要手术干预，但一些外斜视患者仍能发展出较高水平的双眼视功能。斜肌亢进和DVD很常见，通常在1岁时就会出现。与婴儿型内斜视不同，眼球震颤很少见。
