This retrospective study compared iris melanoma in children versus adults and found significant clinical differences between the groups. In children, tumor size was smaller and there was less tumor seeding in the angle and a lower incidence of secondary glaucoma. However, there was no significant difference in metastasis or death by age group.
The study was a nonrandomized clinical case series including all patients with a clinical diagnosis of iris melanoma managed at the Ocular Oncology Service at Wills Eye Institute in Philadelphia during a 40-year period.
Of 8,101 eyes with uveal melanoma, there were 317 (4 percent) with iris melanoma, of which 8 percent were children (age 20 and younger), 59 percent mid-adults (21 to 60 years), and 33 percent older adults (age 61 and older).
Significant age-related differences were found in terms of mean tumor basal diameter, tapioca appearance, mean IOP, secondary glaucoma, tumor seeding in the angle, and mean number of clock hours of angle seeding. There were no age-related differences in race, sex, tumor quadrant, thickness, pigmentation, associated corectopia, ectropion uveae, hyphema or extraocular extension.
Multivariate analysis of factors predictive of metastasis included extraocular extension and high IOP. Factors predictive of death included increased tumor thickness and high IOP.
The authors note the relatively small number of patients they have seen with this rare tumor. In addition, the number of events for metastasis and death was low, making statistical differences among the groups unlikely. Nevertheless, this is the largest series on this topic.