Author’s Disclosure Block: Mohammed Khan, none; Anna Dalgleish, none; Nastaran Hajizadeh, none; Irina Dinu, none; Hermina Strungaru, none

Abstract Body
Purpose: The purpose of the study is to determine if the dysfunctional lens index scale (DLI) measured by iTRACE is a valuable and objective measurement to evaluate the severity of cataract depending on certain type of cataracts. Study Design: This is a single-center, retrospective, non-interventional observational study. Participants seen at the Eye Physicians and Surgeons' clinic from January 2023 to July 2024 were included. Inclusion criteria were a clinical diagnosis of any cataract type, age 18 years or older, and healthy eyes with only cataracts. Participants were excluded if they had previous history of ocular trauma, ocular surgery, including laser refractive treatment, irregular corneal astigmatism, corneal opacity, scarring, or dystrophies, ocular diseases other than age-related cataract, and pupil diameters of less than 4.0 mm in dark. Methods: All patients underwent a comprehensive ophthalmologic examination by a single surgeon. This included lens opacification classification system II grading (LOCS II) grading of their cataracts following pupil dilation and DLI measurement via the ray-tracing aberrometry system (iTrace Visual Function Analyzer by Tracey Technologies). Only patients with pupil size 4.00mm or larger (in the dark) with good quality scans were included in the study. Results: We collected date from 165 eyes across 96 patients, 63% of whom were female with a mean age of 68.73 years (range 39-89 years of age). The DLI was significantly correlated with severity of nuclear sclerotic cataract (NSC) (P-value<0.001) and severity of posterior subcapsular cataract (PSCC) (P-value<0.001). When DLI increases, the severity of NSC and PSCC decrease. There were no statistically significant differences between the mean DLI and the severity of anterior cortical cataract (ACC)(P-value=0.1854). There is significant correlation (-0.5150) between DLI and best corrected vision acuity (P-value=2.368e-12), when DLI increases, BCVA decreases. The cut-off for DLI to predict surgery was 8.05. Patients with DLI more than 8.05 do not need surgery and patients with DLI less than 8.05 need surgery (sensitivity=0.81, specificity=0.83, AUC=0.82). Conclusions: The DLI can be a valuable objective measurement for the severity of nuclear sclerotic and posterior subcapsular cataracts, but not for anterior cortical cataract. A cut-off DLI less than 8.05 could be a criterion for preoperative decision-making in cataract surgery.