Amblyopia in congenital ptosis.

This study evaluates the association between congenital ptosis and amblyopia. Amblyopia was detected in 7 of 36 (19%) patients with congenital ptosis. Two patients (6%) with amblyopia had no contributing factors other than the presence of congenital ptosis. A statistically significant correlation between severe nonocclusive ptosis (greater than or equal to 4 mm) and the development of amblyopia was identified. No new cases of amblyopia developed after surgical repair of the ptosis, suggesting early surgery for severe nonocclusive congenital ptosis may decrease the incidence of amblyopia.

Growth of the internal and external eye in term and preterm infants.

BACKGROUND: Better knowledge of the growth patterns of the external and internal eyes of neonates would permit more accurate diagnosis of disorders that affect ocular size such as infantile glaucoma and microphthalmos. Such disorders preferentially may affect certain parts of the internal eye but not other parts. No previous study statistically has evaluated internal ocular growth in preterm newborns. METHODS: A-scan ultrasonography was applied directly to the corneas of 101 healthy preterm and term newborns to determine axial length, anterior chamber depth, lens thickness, and vitreous chamber depth. The growth of these structures was evaluated by correlation and regression analyses. RESULTS: At term, the mean measurements were axial length, 16.2 mm; anterior chamber depth, 2.0 mm; lens thickness, 3.8 mm; and vitreous chamber depth, 10.5 mm. Postconceptional age correlated to axial length (P < 0.001), anterior chamber depth (P = 0.032), and vitreous chamber depth (P < 0.001), but not to lens thickness (P = 0.48). By regression analysis, the eyes of males grew faster than those of females (P < 0.001) mainly due to the vitreous chamber. CONCLUSION: In the last trimester and first 2 postnatal months, lens thickness remains constant, while the anterior chamber and, especially, the vitreous chamber deepen.

The effect of anterior transposition of the inferior oblique muscle.

The effect of anterior transposition of the insertion of the inferior oblique muscle was compared with the results from conventional inferior oblique muscle recession in 50 patients. Even though both groups of patients had a similar degree of overaction preoperatively, postoperative inferior oblique muscle action was weaker (P < .01) and upgaze more limited P < .01) in the anterior transposition group. These data suggest that anterior transposition serves to convert the inferior oblique muscle from an elevator to a depressor on attempted elevation. Because anterior transposition is such a powerful weakening operation, we suggest that it be reserved for patients with moderate to severe inferior oblique muscle overaction. To avoid postoperative hypotropia in upgaze, anterior transposition should be performed in both eyes for bilateral inferior oblique muscle overaction and not unilaterally.

Distance stereoacuity. Assessing control in intermittent exotropia.

BACKGROUND: A patient's ability to control an intermittent exotropic deviation is usually assessed by subjective means such as observation of control in the office, questioning the patient and/or family about control at home, and reports of monocular eye closure in bright light. An objective method of assessing control has not been developed. PURPOSE: The purposes of this study are to determine if distance stereoacuity was different in patients with intermittent exotropia than in normal subjects and to determine if distance stereoacuity could be used as a objective means of assessing control in intermittent exotropia. METHODS: The authors evaluated near and distance stereoacuity in 44 patients with intermittent exotropia and 50 normal subjects. Patients with intermittent exotropia also were assessed for office control, home control, and monocular eye closure in bright light. Additionally, six patients who underwent successful surgery were reevaluated postoperatively. CONCLUSION: Normal subjects and patients with intermittent exotropia had good near stereoacuity. Patients with intermittent exotropia demonstrated significantly worse distance stereoacuity than the population of normal subjects (P < 0.001). Five of six patients with poor distance stereoacuity preoperatively had dramatic improvement in distance stereoacuity postoperatively. Diminished distance stereoacuity seems to be an objective measure of poor control of the exotropic deviation. This test may provide important objective criteria for deciding when to perform surgery in patients with intermittent exotropia.

Congenital double elevator palsy: vertical saccadic velocity utilizing the scleral search coil technique.

Four patients with congenital double elevator palsy were studied who had clinically brisk elevation of the affected eye from downgaze to the midline position of rest, but severely limited or absent elevation above primary position. Forced duction tests were negative and Bell's phenomenon was present preoperatively in all patients. To clarify why upgaze saccades clinically seemed intact below but not above midline, vertical saccadic velocities were measured using the scleral search coil technique. The tracings of three cases suggest sufficient superior rectus function to generate a normal upward saccadic trajectory. A supranuclear lesion is the most likely etiology of the inability to elevate the eye well above primary position in these three patients. In a fourth patient, the reduced ability to elevate the affected eye above primary position is caused by a superior rectus paresis with decreased upward saccadic velocities. We suggest at least three distinct groups of patients present clinically as double elevator palsy: primary inferior rectus restriction, primary superior rectus paresis or palsy, and congenital supranuclear elevation deficiency.