Structural and Functional Outcomes of Optic Pathway Compression in Pituitary Adenoma: A Prospective Pilot OCT Study

Michal Březík,1,2 Jan Němčanský,1,3 Tomáš Krejčí,4,5 Ondřej Polách,1,6 Juraj Timkovič,1,3 Oldřich Chrapek2,7 1Clinic of Ophthalmology, University Hospital Ostrava, Ostrava, Czech Republic; 2Department of Ophthalmology, Faculty of Medicine Masaryk University, Brno, Czech Republic; 3Department of Craniofacial Surgery, Faculty of Medicine University of Ostrava, Ostrava, Czech Republic; 4Clinic of Neurosurgery, University Hospital Ostrava, Ostrava, Czech Republic; 5Department of Clinical Neurosciences, Faculty of Medicine University of Ostrava, Ostrava, Czech Republic; 6Department of Ophthalmology, Faculty of Medicine in Hradec Kralove Charles University, Hradec Kralove, Czech Republic; 7Clinic of Ophthalmology, University Hospital Brno, Brno, Czech RepublicCorrespondence: Jan Němčanský, Clinic of Ophthalmology, University Hospital Ostrava, 17. listopadu 1790/5, 708 52, Ostrava–Poruba, Czech Republic, Email [email protected]: To evaluate the anatomical and functional effects of optic chiasm compression caused by a pituitary adenoma both before and after surgery.Patients and Methods: Short-term prospective study of 48 eyes from 24 patients who underwent radical surgery for pituitary adenoma. Comprehensive ophthalmological assessment was performed and OCT (optical coherence tomography) parameters (RNFL - retinal nerve fiber layer, GCL - ganglion cell layer, BMO-MRW - Bruch’s membrane opening-minimum rim width) and BVCA (best corrected visual acuity) using ETDRS (Early Treatment Diabetic Retinopathy Study) chart were evaluated before surgery and 3 months after surgery.Results: Over time, a decline in RNFL was observed in circular scans of 3.5 mm, 4.1 mm, and 4.7 mm (p = 0.001– 0.04), as well as in GCL (p = 0.001– 0.022) and BMO-MRW (p = 0.001– 0.033). The median improvement in vision was 4 letters (IQR 0– 6) (p < 0.001). A positive correlation between RNFL and visual improvement was found only in the TS (temporo-superior) sector in the 4.7 mm circle (p = 0.018). A negative correlation was observed between the difference between preoperative and normative RNFL and GCL values and the postoperative BCVA (RNFL p = 0.005– 0.046, GCL p = 0.009– 0.022).Conclusion: Following radical surgery all three OCT parameters show a significant decline. While the reduction between preoperative and postoperative values does not influence the final visual outcome, preoperative atrophy of the RNFL and the GCL is negatively correlated with postoperative BCVA. The BMO-MRW may represent a novel marker of compressive neuropathy.Keywords: RNFL, GCL, BMO-MRW, ETDRS