Ординатура / Офтальмология / Английские материалы / Essentials in Ophthalmology Oculoplastics and Orbit_Guthoff, Katowitz_2007

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Fig. 6.1  Capillary hemangioma in the superotemporal quadrant of the orbit causing displacement of the globe

Fig. 6.2  Mechanical ptosis secondary to capillary hemangioma in the upper eyelid resulting in deprivation amblyopia

Energy (CDE) renders color intensity as a function of blood flow. A red color scale is used, by convention, with color intensity being approximately proportional to the number of moving cells and the technique may be used to estimate the density of blood vessels in hemangiomas (Fig. 6.3a). Spectral Doppler examination re-

sults in a real-time graphical output, known as a “spectrogram” or “spectrograph,” which presents the real-time velocity of blood flow at a particular point within a chosen vessel, flow toward the probe being displayed above the time axis, and vice-versa (Fig. 6.3b).

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Summary for the Clinician

■Capillary hemangioma:

-Is the most common orbital vascular anomaly in childhood.

-Typically enlarges before spontaneously regressing.

-May be complicated by amblyopia in up to half of cases, this being caused by astigmatism, visual deprivation, or ocular imbalance, typically occurring within the first 2 years of life.

■Doppler ultrasonography identifies lesions with acoustic heterogeneity, high spatial density of vessels, and high internal blood velocity.

■The etiology remains unknown, although circumstantial evidence implicates either placenta-to-embryo embolization or aberrant placental differentiation within the embryo.

■Treatment options include glucocorticoids and/or surgical excision.

6.2New Insights into the Natural History of Periorbital Capillary Hemangiomas

Pediatric capillary hemangiomas are characterized by an early growth period and a later involutional phase [24]. The proliferative phase is due to a rapid division of both immature vascular endothelium [14] (this division is thought to be influenced by an abnormal proliferation of mast cells [22]) and adjacent pericytes, which continue to proliferate in the postpartum period. Involution of the hemangioma leads to a fibro-fatty residuum, with recent evidence implicating a persistence of mesenchymal stem cells within the hemangioma, these later forming adipocytes [45].

Although the literature frequently describes periocular capillary hemangiomas as lesions that gradually regress following an initial period of growth, new evidence suggests that their proliferation, involution, and variations in internal blood velocity may be more complex than once thought.

6.2.1How Long and How Significant is the Growth Phase of Capillary Hemangiomas?

Using more objective measures, the natural history for a large cohort of pediatric periorbital capillary hemangiomas has recently been reported for the first time [42]. A series of repeated ultrasonographic assessments (a median of seven assessments) was made in a group of infants in whom neither medical nor surgical intervention was required. Using Doppler ultrasonography (Sect. 6.1.2), the estimated volume and maximum internal blood velocity was followed in a cohort of 24 children, of whom exactly one half were boys. Although involvement of the upper and lower eyelids was the same, there was a left-sided predominance (17 out of

24lesions).

The lesion became clinically apparent at the

age of 2.1 months (range 0–14 months), and the average age at last visit (when the lesion had markedly regressed, so as to pose no threat to visual development) was 44.4 months (range 10–100 months). The maximum estimated size of the capillary hemangioma in this group varied between 0.92 ml and 8.98 ml (mean 4.12 ml) and was, therefore, larger than the developing globe in many cases.

Periocular capillary hemangiomas have been historically described as undergoing involution after an early period of growth, and this study confirmed that there is, indeed, an initial rise in volume in most children (20 out of 24). The phase of expansion would, however, appear longer than the traditionally accepted period of 12–18 months, with the age of greatest volume being as late as 60 months in one child and occurring at an average of 20 months. Over threequarters of hemangiomas assessed within the first year of life had increased in size after the first measurement (Fig. 6.4a). On average, a doubling of volume in the first year of life occurred, with the greatest change observed being a four-fold increase. During the first 18 months after birth, the hemangiomas increased by up to nine times the initial volume (4–930%).

In practical terms, most children will show a marked expansion of periocular hemangiomas and this will typically continue for up to 2 years, but may be ultrasonographically detectable beyond the child’s 7th birthday (Fig. 6.4b). The relative volume effect of such late expansion(s) is, however, reduced by growth of the orbital cavity during the same period.

6.2.2What is the Nature

of Involution for Capillary Hemangiomas?

Longitudinal studies in an untreated group of children have, for the first time, allowed a description of the decay patterns, or profiles, for these lesions [42]. In contrast to the traditionally held view that capillary hemangiomas undergo a gradual involution, it would appear that many

of these lesions demonstrate a series of cyclical changes in volume and blood velocity, these taking the form of damping oscillations around an exponential pattern of decay (Fig. 6.4a).

In children with 5 or more datasets, threequarters showed two or more volume “peaks,” half had three or more volume peaks, and two

children showed four clearly defined oscillations during their follow-up. Two features of these volume oscillations were described. First, there appeared to be a sequential decrease in size (“damping”) of the peaks and, second, for each child the interval between peaks increased. For the whole group, the average first interval (between the first

and second volume peaks) was 8 months, this being significantly shorter than the second interval (18 months) and the third interval (15.5 months; occurring in just 2 patients). One interpretation of these findings is that natural involution, resulting in an exponential profile, is masked by periods of episodic growth, these growth phases being pronounced early in life, with the “height” of subsequent peaks being a function both of residual tissue volume in the preceding trough, and the intensity and duration of the proliferative phase. Whether involution – possibly by apoptosis – increases in response to the proliferative phase (the volume loss after proliferation being marked in some children; Fig. 6.4c) is uncertain, but it is interesting to note that these volume peaks were never sustained for more than two or three consecutive measurements.

Several children in this “natural history” group show, however, an erratic decay profile – some with a final volume measurement (as late as 3 years of age) similar to, or even higher than, the initial measurement. These observations further support the concept of a complex and dynamic balance between proliferation and involution, which

–not being limited to the early postpartum period

–may continue beyond the 5th year of life.

Less is known about time-related changes in blood velocity within pediatric hemangiomas: peak velocities as high as 100 cm/s have been recorded, greater than that within the aorta (~50 cm/s) or normal capillary beds (~0.1 cm/s) [42]. In many cases the periodicity, and overall pattern, of the velocities correlates closely with that of the volume profiles – suggesting that the proliferation and involution of mesenchymal and endothelial tissues may run in parallel (Fig. 6.4a). The ages at which these peak velocities were recorded reflect that of volume measurements, ranging from 3 to 52 months. Finally, late velocity spikes were observed in over a third of patients – further evidence that the natural behavior of capillary hemangiomata remains dynamic for several years after birth (Fig. 6.4b, c).

6.2.3Do Capillary Hemangiomas Undergo Complete Involution?

In contradistinction to the traditional view that capillary hemangiomas undergo complete regression, ultrasonographic studies by the current authors suggest that capillary hemangiomas

may not regress completely, with persistent tissue identifiable ultrasonographically in many patients after clinical resolution of the lesion [42], this tissue being in the form of a fibro-fatty residuum [48]. Indeed, in the natural history group, a final volume of less than 10% of the maximum was recorded in only a quarter of children and in only one-sixth of children was the lesion undetectable on ultrasound examination – this being at an average of 72 months (range 53–100 months) [42]. In 8 children in whom there was complete clinical regression of the hemangioma – all at more than 4 years’ follow-up – the lesion could still be detected ultrasonographically in 4 children [42].

Summary for the Clinician

■Recent Doppler ultrasonography studies indicate that:

-The natural history of capillary hemangiomas is one of early postpartum growth followed by cycles of decay and proliferation.

-A doubling of hemangioma size may occur within the first year of life.

-The peaks and frequency of volume expansions typically decrease over time.

-Lesions may not regress completely, final decay leading to a fibro-fatty residuum.

■Several children showed erratic decay profiles, suggesting a complex biological equilibrium between proliferation and involution, which may persist beyond the seventh year of life.

6.3Changes in Capillary Hemangiomas After Local Steroid Therapy

The natural history group of children with hemangiomas has, for the first time, recorded the ultrasonographic characteristics for these lesions and this has facilitated a comparison with those of children who required local steroid therapy for maintenance of visual development. A group

of 9 children were followed after using a regime of intralesional and perilesional steroid injection (Sect. 6.1.3).

6.3.1Hemangioma Characteristics Associated with Need

for Intervention

Nine children received local steroid therapy and one of the children also had surgical resection of the hemangioma. Infants requiring treatment presented at a significantly earlier age than the natural history group, all attending within a month of birth, and the mean duration of followup was significantly longer in the treated group (mean 65 months; range 26–105) than in the natural history group.

Unlike the equal sex distribution in the natural history group [42], 8 of the 9 treated children were girls – this reflecting the 1.5 female predominance reported elsewhere [5, 24], and the 3.2:2 ratio for all patients managed by the current author (GER). The cause of this female preponderance within the treated group remains uncertain, but might reflect the influence of different hormones or local cytokines on the vascular endothelium, pericytes or mesenchyme of these childhood hemangiomas.

The average maximum size in the treated children was 8.9 ml, over twice the size of that in the untreated group, and the maximum internal velocity in these larger lesions (mean 63.8 cm/s) tended to be greater than that in the untreated hemangiomas (mean 52 cm/s).

6.3.2Involutional Changes in Volume and Velocity After Steroid Therapy

The changes in volume and velocity during involution of steroid-treated hemangiomas show a similar cyclical pattern to that in the natural history group, but with some notable differences. At the time when steroid therapy was given, early variations in size and velocity were typically less extreme compared with those in untreated children. Steroid therapy causes a significant, and sometimes prolonged, “damping” of the cyclical

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