The Lanindar test: A method of evaluating patient suitability for cataract surgery using assisted topical anaesthesia

Abstract

Aim: To evaluate an office-based Lanindar (light and nociceptive interaction noting distress and response) test to assist in the assessment of patient suitability for assisted topical anaesthesia (ATA) during phacoemulsification. Methods: The Lanindar test was carried out at the preoperative assessment of 716 consecutive patients in the office of one of the authors (ICF). A standard desk lamp was shone in each patient's eye after pupillary dilation, while simultaneously elevating the upper eyelid digitally. A negative test indicated patient hypersensitivity to the light and aversion to digital pressure on the upper eyelid. A positive test was indicated by the patient feeling comfort and lack of blepharospasm and withdrawal in response to the light and digital pressure. χ2 and Fisher's exact tests were used to assess the association between Lanindar results and suitability for ATA. The positive predictive value and specificity of the test as an indicator of patient suitability for ATA were calculated. Visual acuities at 1 and 4 weeks post-operative periods were compared between the ATA and ALA/GA (assisted local anaesthesia/general anaesthesia) group of patients. Results: About 86.7% were Lanindar positive and 98.9% of these patients tolerated ATA. χ2 and Fisher's exact tests demonstrated a significant association of a positive Lanindar test with successful ATA (χ2=660, P<0.001, Fisher's: P<0.001). The positive predictive value and specificity of the test were 98% (95% CI=98.04-99.7%) and 93.14% (95% CI=88.23-98.04%), respectively. Visual acuity outcomes were similar in the ATA and ALA/GA groups. Conclusion: The Lanindar is a simple, highly specific, office-based test to determine patient suitability for phacoemulsification under ATA. © 2009 Macmillan Publishers Limited All rights reserved.