Supplementary Material for: Orbital complications and cost analysis of enucleation by myoconjunctival versus conventional techniques for retinoblastoma

Introduction: To compare complication rates and hospital costs of myoconjunctival versus conventional enucleation techniques in retinoblastoma. Methods: This retrospective cohort and cost analysis reviewed patients with retinoblastoma treated by primary or secondary enucleation between 2003-2021 and a minimum 6-month follow-up. Cases were reviewed for three post-surgical complications: chronic conjunctivitis, implant exposure/extrusion, and cellulitis. Cases were excluded if surgery was performed elsewhere or documentation was incomplete. Treatment costs were estimated based on two sample cases billed in 2021 that manifested the studied complications and represented each of the two surgical techniques. Univariate and multivariate analyses were applied to compare complication rates and treatment costs. Results: Included were 180 eyes (179 patients); 140 were excluded. Patients were median age 18.9 (0-104.4) months at diagnosis, the majority male (94, 52%), with unilateral (115, 64%) Group D or E (163, 91%) eyes. Enucleation was performed by conventional techniques in 107 eyes (59%) and by myoconjunctival approach in 73 (41%). Orbital complications occurred in 61 eyes (34%) during a median follow-up of 7.9 (0.5-33.7) years, more frequently in the conventional technique group (p=0.014). The myoconjunctival technique had significantly lower costs for implant price (p<0.001) and estimated treatment cost, including complication management (p<0.001). Conclusion: Enucleation by myoconjunctival technique showed significantly less complication burden and treatment cost, indicating advantages over conventional approaches. Study limitations include the retrospective nature, confounders' complexity, and follow-up time variations.