Purpose: 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.
Materials and methods: 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.
Results: 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).
Conclusion: A significantly smaller volume of the affected globe is an additional feature of Coats disease.