Article
The merit of quantitative pupillometry in patients with tumours adjacent to structures of the optic system – first results of an on-going prospective study
Der Stellenwert der quantitativen Pupillometrie bei Tumoren mit Kompression der Strukturen des optischen Systems: erste Ergebnisse einer laufenden prospektiven Studie
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Published: | May 25, 2022 |
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Objective: Quantitative pupillometry has been increasingly applied in neurocritical care as an effective, affordable, easy-to-use, and reliable tool. Previous evidence supports that early detection of abnormal pupillometry findings might expedite emergent care to improve clinical outcomes.In the setting of neuro-oncological care, tumors, such as pituitary tumors or medial sphenoid wing meningiomas, can cause compression of the optic chiasm resulting in visual impairment and potentially cause abnormal pupillometry findings.However, this technique has not yet been applied to evaluate decompression in patients with tumors adjacent to these structures.Therefore, our pilot study aims to evaluate the merit of pupillometry in streamlining treatment modalities in patients undergoing surgical resection of tumors compressing structures of the optic system.
Methods: This is an on-going prospective study collecting pupillometry data from patients with tumors shifting structures of the optic system as well as of patients admitted in neurocritical care. Pupillometry using the automated NPi 200® pupillometer was performed in 10 patients pre- and post-resection of tumors in proximity to the visual system. The neurological pupillometry index (NPi) was analyzed as computed parameter and correlated with standardized visual acuity assessments.
Results: A total of 10 patients with a mean age of 53 years (SD 14.5) were analyzed. Seven patients suffered from pituitary tumors, one patient from a left-sided optic meningioma and two patients from left-sided medial sphenoid wing meningiomas. All patients reported visual impairment because of the tumor mass. The preoperative NPi was <4.0 in all patients in at least one pupil. Mean bilateral NPi were pathologic preoperatively, of the left eye at 3.7 (SD 0.6) and of the right eye at 3.8 (SD 0.3), respectively. Postoperative assessment revealed NPi improvement in nine of ten patients ranging from 6% to 50%, when compared to baseline. The mean NPi of the left eye increased 17.5% (SD 15.1%) and of the right eye 11.6% (SD 11.9).This increase correlated with improved visual acuity.
Conclusion: Our preliminary results suggest that quantitative pupillometry can detect compression of structures of the visual system caused by tumors. Postoperative improvement of NPi values may indicate sufficient decompression of these structures.In future analysis, we anticipate to present data on a larger cohort aiming to substantiate the potential and limitations of this technique.