Abstract
Purpose: :
Recently the ocular echographic sign defined as the presence of ultrasonographic hollowness (UH), has been identified as a predictive growth feature of choroidal nevi into melanoma (Shields et al., 2009). The purpose of this work is to evaluate this sign in choroidal nevi by means of 10 and 20 MHz ultrasonographic techniques.
Methods: :
An observational study has been carried out in 50 choroidal nevi of 50 eyes (right eye: n=22; left eye: n=28) belonging to 47 patients (31 women and 15 men; mean age: 63,63 years). In all cases patients were studied performing complete ophthalmologic and ultrasonographic examinations (10 MHz (I3 ABD-System) and 20 MHz (Quantel) probes)). In addition, each case received a risk score based in the classification proposed by Shields et al. (2009): greater thickness, subretinal fluid, symptoms, orange pigment, margin near disc, UH and absence of halo.
Results: :
The localization of nevi was centred in the posterior pole in 29 cases, in the equator in 14 cases and in the periphery in 7 cases. Both, 10 and 20 MHz scan studies were completed in 33 cases. No statistically significant differences were found between nevi dimensions obtained by 10 and 20 MHz techniques. However, UH was detected in 4 cases with 10 MHz probe while 16 cases showed the same sign using 20 MHz probe. Positive correlations between UH and height of the tumor and also between UH and the risk score were detected.
Conclusions: :
UH is easier to detect by means of 20 MHz than 10MHz ultrasonography. This sign appears to be correlated with the height of the tumor and with the risk score of transformation in choroidal melanoma. Thus, the authors consider that UH measurement by 20 MHz ultrasonography could have a significant value as predictive growth factor in choroidal nevi.
Keywords: melanoma • oncology • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)