Neurological Pupil Index could be an effective tool for assessing patients with a subarachnoid hemorrhage.
Neurological Pupil Index could be an effective tool for assessing patients with a subarachnoid hemorrhage. Photo: NeurOptics. Click image to enlarge.

Neuro-ophthalmic concerns always raise the stakes, given the seriousness of the potential etiologies. Optometrists who screen pupil reactivity with an automated pupillometer that makes use of a metric called the Neurological Pupil Index (NPI), which provides a quantitative assessment of pupil reactivity, may be able to offer prognostic estimates for patients with subarachnoid hemorrhage. Researchers recently initiated a retrospective analysis to better understand the potential of this approach.

The study included 53 acute subarachnoid hemorrhage patients. Data recorded at admission included age, sex, respiratory status, NPI and a measure of disease severity called the Acute Physiology and Chronic Health Evaluation (APACHE)-II score. 

In this relatively small group of subjects , 40% had poor clinical outcomes and 4% died. The researchers reported that only APACHE-II score and respiratory failure were significantly associated with poor clinical outcomes. They observed that the NPI was lower among patients with clinical outcomes compared with those without; however, neither was significant.

The data also revealed that the most accurate algorithms for death and poor clinical outcome included the NPI, according to the study authors. Given the limitations of current scoring systems, there is a need for noninvasive biomarkers for risk of death and secondary brain injury among patients with subarachnoid hemorrhage.

The researchers noted the positive correlation and described it as “indicating its potential prognostic value in the management of patients with acute subarachnoid hemorrhage,” they wrote in their paper. “Although our results do not establish a definitive association between the initial Neurological Pupil Index and adverse patient outcomes, they add to the emerging body of literature suggesting the Neurological Pupil Index is of prognostic value in patients with acute subarachnoid hemorrhage.”

While these findings shed light on the potential of this approach, the researchers emphasized the need for further investigation through a prospective study that has broader patient enrollment.

Sharma RA, Garza PS, Biousse V, et al. Prognostic Value of the Neurological Pupil Index in Patients With Acute Subarachnoid Hemorrhage. J Neuroophthalmol. February 15, 2022 [Epub ahead of print].