B-scan measurements of intraocular tumor heights intraoperatively, before and after radioactive plaque application: A comparative prospective study.

Purpose: To assess the difference in intraocular tumors height measurements intraoperatively before and after radioactive plaque application.

Methodology: Twenty-four eyes of 24 patients with intraocular tumors, candidates for radioactive therapy, were included. Each tumor was measured at the same setting before and after plaque application independently by 3 sonographers, using a 20-MHz B-scan transducer. Mean pre-plaque and post-plaque measurements were calculated and recorded. An A-scan vector aided in identification of the inner and outer tumor surfaces.

Results: Each patient was examined independently three times by three experienced ultrasonographers within the same setting to assess interobserver variability. There was no statistically significant difference between the 3 examiners' readings, with P-value 0.99 for pre-plaque height and 0.97 for post-plaque height. Mean pre-plaque height was 5.16±2.11mm, while post-plaque height was 5.51±2.1mm (P-value 0.001). The Spearman correlation test showed that initial tumor height was negatively correlated with the difference between both heights, but with no statistical significance.

Conclusion: Intraocular tumor height measurement differs significantly before and after plaque application. Use of the pre-plaque height is advised until further studies are performed to assess the effect of this difference on treatment outcomes.