Intraocular pressure changes following intravitreal melphalan and topotecan for the treatment of retinoblastoma with vitreous seeding

Abstract

Purpose: To investigate the impact of intravitreal chemotherapy on intraocular pressure (IOP) in children with retinoblastoma. Methods: This was a retrospective study of 10 eyes of 10 patients with retinoblastoma (7 males, 3 females, mean age: 33.6 ± 9.4 months) with vitreous seeding injected with intravitreal melphalan and topotecan. IOP was measured with Tono-pen (Reichert, Inc., Buffalo, NY) at baseline prior to injecting and then repeatedly following each intravitreal injection. Results: Mean pre-injection IOP was 8.2 ± 2.3 mm Hg (range: 4 to 12 mm Hg). Mean IOP 1 to 30 seconds after intravitreal melphalan (first injection) was 45.4 ± 14.3 mm Hg. The IOP of 89.5% of patients declined to 29 mm Hg or less in a mean 153.3 ± 97.5 seconds. Mean IOP 1 to 30 seconds after intravitreal topotecan (second injection) was 44.5 ± 11.0 mm Hg, which decreased to 31.0 ± 5.0 mm Hg by 150 seconds after injection. No significant relationship was found between age and post-injection IOP elevation. IOP exceeded the calculated mean arterial perfusion pressure in four encounters. Conclusions: Intravitreal chemotherapy caused a transient rise in IOP. Post-injection IOP elevations can reach levels that may exceed mean arterial pressure.