Optical coherence tomography and visual field discordance in optic chiasm compression in patients with pituitary adenomas.

PURPOSE: To evaluate whether optical coherence tomography (OCT) structural measurements correlate with visual field (VF) deficits in pituitary adenomas and to determine when OCT abnormalities appear relative to VF defects.

METHODS

This retrospective study included 95 patients (190 eyes) who underwent magnetic resonance imaging, automated perimetry, and OCT between 2013 and 2023. Patients were classified as compression (n = 67), abutting (n = 15), or noncontact (n = 13). VF index ([VFI], mean deviation [MD], pattern standard deviation [PSD]) and OCT parameters (retinal nerve fibre layer [RNFL] and ganglion cell-inner plexiform layer [GC-IPL]) were compared across groups and by VF defect status.

RESULTS

VF differed significantly across groups. The compression group showed worse VFI (mean [SD], 81.36 [27.42] vs 93.86 [12.87] and 95.58 [3.96]; p = .003) and more negative MD (-6.76 [8.46] vs -2.57 [4.23] and -2.77 [2.06] dB; p = .003), with higher PSD (4.85 [4.56] vs 3.12 [3.02] and 2.60 [1.63] dB; p = .01). GC-IPL did not differ across groups (p = .18), although focal thinning was noted. RNFL differed only in the temporal quadrant (p = .038). Correlation analyses revealed weak to moderate associations between VF indices and OCT parameters (r = 0.34-0.69).

CONCLUSIONS

Chiasmal compression is associated with VF loss, whereas OCT parameters do not consistently change in parallel. When OCT abnormalities are present, they are likely to reflect damage that has already progressed beyond the reversible stage and may serve as a prognostic indicator of limited postoperative visual recovery.