Coats disease: smaller volume of the affected globe

To determine whether a significant smaller volume of the affected globe, compared with that of the normal globe, is an additional feature of Coats disease.

Ocular globe volume was assessed in 13 children (11 boys, two girls; age range, 0.6-14 years; mean age, 4.1 years) with Coats disease and in 18 (eight boys, 10 girls; age range, 0.5-12 years; mean age, 3.6 years) with unilateral retinoblastoma. Orbital computed tomographic scans were available for all children; magnetic resonance images were available for 11 children-seven with Coats disease and four with retinoblastoma. For volume estimation, anteroposterior and equatorial diameters of ocular globes were measured. Statistical analysis was conducted with univariate and multivariate methods.

In children with Coats disease, the mean volume of the affected globe was 4,877.03 mm(3) (range, 2,951.47-6,284.70 mm(3)) and that of the normal globe, 6,018.00 mm(3) (range, 4,062.32-7,509.26 mm(3)). In children with retinoblastoma, the mean volume of the affected globe was 4,557.06 mm(3) (range, 1,612.01-7,463.00 mm(3)) and that of the normal globe, 4,402.11 mm(3) (range, 1,360.46- 7,463.00 mm(3)). The Coats disease population had a significantly smaller volume of the affected globe (z = -3.1009; P =.002); the retinoblastoma population did not have a statistically significant trend toward a bigger affected globe volume (z = -1.7064; P =.088). The difference between the affected globe volume and the normal globe volume in children with Coats disease was the only significant independent variable (P =.005).

A significantly smaller volume of the affected globe is an additional feature of Coats disease.