Resident/Fellow Research Day
2001
Echographic Reflectivity as a Risk Factor for Growth of Indeterminate
Pigmented Choroidal Lesions
Sharam Danesh, M.D. Thomas A. Weingeist, M.D. H. Culver Boldt, M.D.
Purpose: The distinction between choroidal
nevi and melanomas for lesions less than 3 mm in size is difficult.
Using Standardized Echography, the characteristic reflectivity seen
in choroidal nevi is high, and in choroidal melanoma is low to medium.
Medium to low reflectivity in inderteminate pigmented choroidal lesions
has been considered to be a risk factor for growth, but this has not
previously been documented. We set out to investigate echographic reflectivity
as a risk factor for growth of indeterminate pigmented choroidal lesions.
Methods: We retrospectively studied all
patients with indeterminate choroidal lesions presenting to the University
of Iowa, Department of Ophthalmology and Visual Sciences after 1990.
Eligible lesions were defined as having apical height of 1.5 to 3.0
mm and basal dimensions of less than 16.0 mm. Clinical features of the
tumors were determined from the clinical records and fundus photographs.
All lesions had been evaluated with standardized A-scan echography by
experienced technicians. Growth was defined as an increase of 0.4 mm
in apical height or 0.5 mm of lateral extension. A Cox proportional
hazards regression model was used to asses the association between ultrasound
and clinical features to tumor growth.
Results: Of total of 176 patients with
indeterminate choroidal lesions, 54 grew during the follow up. Growth
occurred after a median of 35 months (range: 1 to 180 months). In univariate
analysis, echographic reflectivity, presence of orange pigment, symptoms,
subretinal fluid and absence of drusen were significantly associated
with tumor growth (p<0.05). When the baseline variables were analysed
in a multivariate Cox proportional hazard regression model, only echographic
reflectivity (p=<0.0001) and presence of orange pigment (p=0.0002)
remained significantly associated with tumor growth. Absence of drusen
was of borderline significance (p=0.0598).
Conclusion: we have found echographic
reflectivity is highly correlated with time to growth for indeterminate
choroidal lesions. This correlation remains significant after a multivariate
analysis with other clinical parameters. This is an important feature
which should be considered when making clinical decisions on management
and treatment of these lesions.
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