Strabismus in retinoblastoma survivors with long-term follow-up.

PURPOSE:To report the long-term strabismus rate in salvaged retinoblastoma (Rb) patients and investigate possible risk factors leading to strabismus. METHODS:The medical records of patients with Rb presenting at a single institution over a 9-year period were reviewed retrospectively with regard to ocular alignment outcomes after long-term follow-up. RESULTS:A total of 64 eyes of 42 patients (22 bilateral cases [52%]) were included, presenting with International Intraocular Retinoblastoma Classification (IIRC) in the worse eye as follows: group A (n = 1), B (n = 16), C (n = 12), D (n = 11), no Rb (n = 2). Fifteen patients (36%) were initially referred because of family history of Rb. Mean age at presentation was 8.2 months (range, 0.3-58.3 months). Overall treatments included intravenous chemotherapy (62 eyes), intraophthalmic artery chemotherapy (10 eyes), brachytherapy (11 eyes), transpupillary thermotherapy (22 eyes), cryotherapy (47 eyes), and external beam radiotherapy (4 eyes). At final follow-up (mean, 93.7 months), 69% of patients had strabismus, with exotropia being the most common type (n = 18), followed by esotropia (n = 8), and alternate exotropia/esotropia (n = 3). On univariate analysis, the worse eye group IIRC and cTNMH, sporadic cases, strabismus, and foveal tumor at presentation were found to be significantly associated with strabismus at final follow-up (P ≤ 0.043). On multivariate analysis, only foveal involvement was found to be significant (P < 0.001). CONCLUSIONS:Strabismus, exotropia in particular, is a common adverse sequela following successful conservative treatment for Rb, with 69% of the present cohort having some type of deviation after long-term follow-up, for which foveal tumor at presentation was found to be a significant risk factor.