NF1 and neoplasm: A similar tendency of higher median tumor growth rates in patients with evidence of impaired VA without statistical significance could be shown in both subgroups of patients with and without NF-1 (NF-1 OPG: 0.137 vs 0.001 cm3/month, p = 0.16; non-NF-1 OPG: 0.036 vs 0.0003 cm3/month, p = 0.18; see Fig. 4B).