Abstract
Purpose :
In acute chemical ocular injuries, the role of pH measurement before irrigation is unclear. We performed a retrospective observational study to determine whether tear film pH measured at presentation in acute chemical eye injuries carries any prognostic value.
Methods :
Data including demographics, pH values, nature of chemical, injury circumstances and severity, and clinical and visual outcomes were assessed from previously collated data from patients presenting to the emergency eye department in a UK tertiary hospital. All patients had pH measured before and after irrigation (irrespective of whether irrigation was started before attendance). Spearman rank correlation coefficient and univariate binary logistic regression analysis were used to assess associations between pH on arrival, injury severity, and clinical and visual outcomes.
Results :
Pre-irrigation pH was recorded in 135 eyes (113 patients, 66.4% male, mean age 35.5 years [range 2 - 78; SD 15.4]; 15 acid, 108 alkali, 12 unknown). In patients presenting within 24 hours of injury (n = 108 eyes), pH positively correlated with injury severity at presentation (rs = 0.20, p = 0.02). In patients with abnormal pH on presentation (6.5 < pH < 7.5; n = 26 eyes), pH correlated strongly with injury severity (rs = 0.72, p < 0.01). There was no significant correlation with visual outcome (rs = 0.12, p = 0.11). Presenting pH was a significant predictive factor for presence of limbal damage at follow up in patients presenting within 24 hours of injury and with follow up after the initial presentation (n = 70 eyes, 60 patients, follow up 1-3929 days, mean 579.4 days, SD 1206.0 days), (p = 0.026, Nagelkirke R2 0.090)
Conclusions :
In patients presenting within 24 hours of injury, pH at presentation positively correlated with injury severity and was a significant predictive factor for limbal damage at follow up. As well as guiding acute management, pH measurement is a useful test as a prognostic indicator to counsel patients.
This is a 2021 ARVO Annual Meeting abstract.