Is the flashlight test of any use in primary care for detecting eyes with shallow anterior chamber

OBJECTIVE: To validate and analyse the usefulness of the flashlight test (FT) in detecting eyes with a shallow anterior chamber in diabetic patients in primary care. DESIGN: Cross-sectional descriptive study. SETTING: Urban health centre and a reference ophthalmology department, Logrono, Spain. PARTICIPANTS: A total of 74 patients with diabetes type 2, selected by consecutive sampling from those seen for an annual check-up. Those patients with movement difficulties, diseases and lesions of the eye, which would hamper the examination, were excluded. A total of 145 eyes were analysed. INTERVENTION: A family doctor and the resident performed the FT. The ophthalmologist carried out the Van Herick test without knowing the results of the FT. PRIMARY OUTCOMES: Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were calculated. The reproducibility was calculated using weighted kappa index. RESULTS: The kappa index was 75%. The specificity was 88.9% and the sensitivity was 98.9% (95% confidence interval (95% CI) 96.1-100.0%). The likelihood that a patient had a negative result could have an angle with a risk of developing glaucoma was 1.1%. The negative likelihood ratio (NLR) was 0.67%. One patient was incorrectly labelled as not having a narrow angle. CONCLUSIONS: The FT is valid and useful for ruling out shallow anterior chamber in type 2 diabetics. It is a simple and innocuous test that can help the family doctor make a decision on pharmacological mydriasis to observe the back of the eye.