Strabismus in Retinopathy of Prematurity: Risk Factors and the Effect of Macular Ectopia

Objectives: This study aimed to examine factors associated with strabismus in patients with retinopathy of prematurity (ROP) and the relationship between strabismus and macular ectopia. Materials and Methods: Patients with ROP were divided into three groups: Group 1, patients with spontaneous regression (n=45); Group 2, patients who received laser treatment (n=70); and Group 3, patients who underwent surgical treatment (n=91). Rates of anisometropia, amblyopia, nystagmus, macular ectopia, and retinal pathologies were evaluated and their impacts on strabismus development were determined. Disc-to-fovea distance (DFD) was measured from color fundus photographs and the correlation of macular ectopia with severity of strabismus was evaluated. Results: A total of 206 patients were included. Rates of anisometropia, amblyopia, nystagmus, macular ectopia, retinal pathologies causing vision loss, and strabismus were higher in Group 3 (p=0.0001) and correlated with higher stages of ROP (p=0.0001). Macular ectopia (p=0.005), retinal pathologies (p=0.005), and amblyopia (p=0.012) had the strongest impact on strabismus development in ROP patients. DFD and strabismus severity were not significantly correlated (p=0.364). Mean visual acuity (VA) was significantly higher in orthophoric patients compared to those with esotropia and exotropia (p=0.027). Esotropic patients had lower VA compared to patients with exotropia, but this finding was not statistically significant (p=0.729). Conclusion: Presence of macular ectopia, retinal pathologies, and amblyopia were the most strongly correlated risk factors for strabismus development in ROP patients. DFD was not associated with severity of strabismus. Exotropia was mostly related to higher DFD and a possible relationship between esotropia and lower VA was observed.