In vitro evaluation of retinoblastoma seeds using red and green lasers

OBJECTIVE: To explore the use of red and green lasers in studying retinoblastoma seeds in pathological samples. METHODS: This study was a retrospective, laboratory-based experimental study, conducted at a tertiary care eye center of northeast India. Medical records were retrospectively analyzed in a 7-year period from 2016 to 2023 to identify enucleated retinoblastoma (RB) eyeballs having tumor seedings. All pathological specimens that were studied using red and green laser pointers (Class III Laser product) were included. Lasers of wavelength 532 nm (green) and 630 nm (red) were used under the objective of compound microscopes to study different RB seeds. The activities of seeds were studied by the use of lasers. The seeds were documented under the objective of the compound microscope. For statistical analysis, IBM SPSS 26 was utilized. The descriptive statistics of the quantitative variables was reported through the metric mean. The categorical variables were described using count and percentages. Independence of categorical variable was carried out using Chi-square test and P values. RESULTS: Thirty-eight specimens with RB seedings at different locations were included in the study. RB seeds in anterior segment (n = 2 cases), over ciliary process (n = 2 cases), vitreous seeds (n = 18 cases), retinal seeds (n = 2 cases), retinal pigment epithelium seeds (n = 3 cases), subretinal seeds (n = 5 cases), combined vitreous and subretinal seeds (n = 6 cases), and calcified seeds (n = 2 cases) were noted. With red and green lasers, varied changes were observed in the RB seeds, particularly the presence and absence of electron dense clouding within the seeds. Active seeds could be differentiated from inactive seeds using the laser technique. CONCLUSION: Use of laser in the present study was first of its kind, carried out to visualize RB seeds at different sites in raw or wet specimens of the enucleated eyeballs. By this technique, active seeds could be differentiated from the inactive seeds based on electron dense clouds within the seeds' configurations.