tumor-to-disc ratio
Measurement comparing tumor dimensions to optic disc diameter, used for standardized tumor size documentation.
Full Definition
Tumor-to-disc ratio is a standardized method of describing intraocular tumor size by comparing the tumor's largest basal diameter to the diameter of the optic disc, which serves as an internal reference standard of approximately 1.5mm. This measurement technique allows for consistent documentation and comparison of tumor sizes across different patients and institutions. The ratio is particularly useful in retinoblastoma and choroidal melanoma classification, where precise size measurements are crucial for staging, treatment selection, and prognosis. Serial measurements can track tumor growth or response to treatment over time.
Usage
Usage note: Standard measurement technique; optic disc diameter is approximately 1.5mm.
In Context
- "The choroidal melanoma measured 3.2 tumor-to-disc ratios in largest basal diameter." — Ophthalmology examination note
- "Serial photography demonstrated stable tumor-to-disc ratio over 12 months of observation." — Follow-up report