Analysis of the Dysfunctional Lens Index as a Novel Criterion for Surgical Decision-Making in Age-Related Cataracts

The dysfunctional lens index (DLI) provided by a ray-tracing aberrometry system is an objective index in cataract assessment. The purpose of this study is to evaluate correlations among Lens Opacities Classification System III (LOCS III) grades, Catquest 9SF scores, and the (DLI) and the DLI's role in surgical decision-making in age-related mixed cataract.This trial was registered at NIH (clinicaltrial.gov) on January 5, 2021 (NCT04711395). In this prospective cross-sectional study, age-related mixed cataract patients were recruited. One high-volume and two low-volume surgeons made surgical decisions based on corrected distance visual acuity (CDVA), LOCS III graded photographs, and Catquest 9SF scores. Their decision-making agreement was evaluated with Cohen's kappa coefficient. Correlations among the parameters were analyzed. The optimal cut-off DLI was calculated using a receiver operating characteristic curve.Overall, 106 patients (106 eyes) were included. Very good agreement levels were noted among the high- and low-volume surgeons (Cohen's kappa coefficient, 0.848) (95% CI, 0.748-0.948). The DLI had the strongest correlation with Catquest 9SF scores (R2 = 0.566), followed by with posterior subcapsular (R2 = 0.418), nuclear opalescence (R2 = 0.388), and cortical (R2 = 0.333, all P < .0001) cataract LOCS III grades. Catquest 9SF scores were correlated with cortical (R2 = 0.249), nuclear opalescence (R2 = 0.278), and posterior subcapsular (R2 = 0.235, all P < .0001) cataract LOCS III grades. A cut-off DLI of 5.36 was identified as a surgical criterion (specificity, 86.9%; sensitivity, 93.3%).The DLI is valuable for objectively assessing patient complaints and lens opacity severity. LOCS III remains effective and economical in assessing early cortical cataracts with relatively clear central lenses. A cut-off DLI ≤5.36 could be a criterion for preoperative decision-making.