Changes in Light Disturbance Analyzer Evaluation in SMILE for High Myopia and Astigmatism.

Purpose: To study the objective change in light disturbance around a glare source using the Light Disturbance Analyzer (LDA) (Binarytarget Lda) and correlate this with the validated subjective quality of vision (QoV) questionnaire in small incision lenticule extraction (SMILE) for high compound myopic astigmatism.

Methods: This was a prospective study recruiting 114 patients undergoing SMILE with attempted spherical equivalent refraction (SEQ) correction from -9.00 to -13.00 diopters (D), and cylinder up to 5.00 D. The LDA was used before and 3 and 12 months after surgery to evaluate the Light Disturbance Area, Light Disturbance Index, Best Fit Circle Radius, and Best Fit Circle Irregularity. Patients completed the Rasch-validated QoV questionnaire before and 12 months after surgery. Correlation analysis was performed between the LDA parameters and the QoV frequency, severity, and bothersomeness for halos and starbursts.

Results: At 12 months, there was a non-statistically signifcant change of 11.9% for Light Disturbance Area and Light Disturbance Index and 6.5% for Best Fit Circle Radius. There was an increase of 81.9% for Best Fit Circle Irregularity ( = .017). Light Disturbance Area, Light Disturbance Index, and Best Fit Circle Radius correlated with bothersomeness for QoV halos, and with frequency, severity and bothersomeness for QoV star-bursts (P < .05), albeit with a low correlation coefficient ( < 0.13). There was no correlation between increase in Best Fit Circle Irregularity and the halo and starburst scores from the QoV questionnaire.

Conclusions: LDA Best Fit Circle Irregularity was found to increase following high myopic SMILE. Other LDA parameters appeared to increase, but a much larger sample would be required to find statistical significance. The change in LDA parameters was only weakly correlated with QoV halo and starburst metrics, representing the wide variation in inter-subject perception. .