Temporal patterns of visual recovery following pituitary tumor resection: A prospective cohort study

•Prospective cohort study of 228 patients undergoing pituitary tumor resection.•Eyes were stratified by pre-operative OCT RNFL measurements.•Visual recovery in eyes with normal RNFL occurred within 6 weeks post-operatively.•Visual recovery in eyes with thin RNFL occurred within 6 months post-operatively. Significant restoration of visual function can occur following pituitary tumor resection, although the time course of visual recovery remains poorly understood. This single-centre, two-year, prospective cohort study investigated the temporal patterns of visual recovery in consecutive patients undergoing pituitary tumor resection, between 2009 and 2018. Eyes were stratified based on pre-operative optical coherence tomography (OCT) retinal nerve fibre layer (RNFL) thickness measurements, with thin RNFL being defined as those within the fifth-percentile of age-matched normative values, and normal RNFL as those above the fifth-percentile. Visual function and OCT parameters were assessed pre-operatively, and at 6 weeks, 6 months, and 2 years post-operatively. 456 eyes of 228 patients (mean ± SD age, 53 ± 15 years) were included, of which 114 (25%) eyes had thin RNFL pre-operatively. Visual field recovery was observed in both groups during the first 6 weeks post-operatively (all Q ≤ 0.02), although improvements in visual field parameters between 6 weeks to 6 months were limited to eyes with thin RNFL (both Q 0.50). Similar trends were observed in linear regression analysis according to baseline visual function in both groups. In summary, eyes with normal RNFL thickness at baseline experienced most of their recovery within the first six weeks following surgery, while eyes with thin RNFL exhibited gradual improvements during the first six months. These findings have important implications when providing patient counselling and prognostication in the pre-operative setting.