Lloyd I C, Dowler J G, Kriss A, Speedwell L, Thompson D A, Russell-Eggitt I, Taylor D
Department of Ophthalmology, Hospital for Sick Children, London.
Br J Ophthalmol. 1995 Sep;79(9):802-6. doi: 10.1136/bjo.79.9.802.
Stimulus deprivation amblyopia is the principal cause of visual impairment in infants with unilateral congenital cataract. Even if lensectomy is undertaken at an early age, intensive postoperative occlusion of the phakic eye is essential for the development of useful vision in the aphakic eye. Despite this, the optimum method of regulating occlusion therapy is uncertain.
Interocular acuity differences identified using clinical preferential looking techniques (Keeler cards) were used to regulate target levels of phakic eye occlusion in a prospective evaluation of 10 systemically, metabolically, and neurologically normal infants in whom dense unilateral cataract was diagnosed before 8 weeks of age, and operated upon by 10 weeks. Actual occlusion levels were recorded each day by parents in a diary. The development of preferential looking acuity in the phakic and aphakic eye were compared with prediction intervals derived from observations on 43 normal children.
Aphakic eye preferential looking acuities were within the normal range at last review in all but one infant. Interocular acuity differences were < or = 0.5 octave in all children older than 1 year of age at last review, and > or = 1 octave in three of four children less than 1 year old at last review (Fisher exact p = 0.033). Phakic eye acuities were within the normal range in all infants at all visits.
Within the first 2 years of life, normal preferential looking acuity may be achieved in both eyes of infants undergoing early surgery for unilateral congenital cataract if occlusion therapy is modulated according to interocular acuity differences quantified by clinical preferential looking techniques.
剥夺性弱视是单侧先天性白内障婴儿视力损害的主要原因。即使在早期进行晶状体切除术,术后对有晶状体眼进行强化遮盖对于无晶状体眼获得有用视力的发育至关重要。尽管如此,调节遮盖治疗的最佳方法仍不确定。
在一项前瞻性评估中,对10名全身、代谢和神经功能正常的婴儿使用临床优先注视技术(基勒卡片)确定的眼间视力差异来调节有晶状体眼的遮盖目标水平,这些婴儿在8周龄前被诊断为单侧致密性白内障,并在10周龄时接受手术。家长每天在日记中记录实际遮盖水平。将有晶状体眼和无晶状体眼优先注视视力的发育情况与从43名正常儿童观察中得出的预测区间进行比较。
除一名婴儿外,在最后一次复查时,所有婴儿的无晶状体眼优先注视视力均在正常范围内。在最后一次复查时,所有1岁以上儿童的眼间视力差异≤0.5倍频程,而在最后一次复查时,4名1岁以下儿童中有3名的眼间视力差异≥1倍频程(Fisher精确检验p = 0.033)。在所有就诊时,所有婴儿的有晶状体眼视力均在正常范围内。
在生命的头2年内,如果根据临床优先注视技术量化的眼间视力差异来调整遮盖治疗,那么接受早期单侧先天性白内障手术的婴儿双眼可能会获得正常的优先注视视力。