Clinical application of a Scheimpflug system for lens density measurements in phacoemulsification

Purpose: To evaluate the relationship between lens density measured using the Pentacam Scheimpflug system and phacodynamics (phacoemulsification time, phacoemulsification energy, and balanced salt solution [BSS] use) in patients with age-related nuclear cataract. Setting: Department of Ophthalmology and Visual Science, Kangnam St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. Methods: This prospective observer-masked study was of eyes with age-related nuclear cataract. Objective lens density (0 to 100 points) was determined using the Scheimpflug system. Subjective grading was by the Lens Opacities Classification System III (LOCS III). The correlations between lens density values and phacoemulsification time, phacoemulsification energy, and BSS use were analyzed prospectively. Results: Fifty-three patients (60 eyes) were evaluated. The mean Scheimpflug-measured lens nuclear density was 14.71 ± 6.12 (SD). There was a positive linear correlation between the Scheimpflug-measured lens nuclear density and the LOCS III grading scores for nuclear opalescence (NO) and nuclear color (NC) (r = 0.734 and 0.719, respectively; both P<.05). The Scheimpflug-measured lens nuclear density correlated with torsional amplitude, time, and cumulated dissipated energy (CDE) (P<.05), but not with BSS use (P = .195). The CDE was more strongly correlated with Scheimpflug-measured lens nuclear density (r = 0.797) than with LOCS III NO or NC scores (r = 0.614 and r = 0.637, respectively). Conclusions: Scheimpflug-measured lens nuclear density correlated with phacoemulsification time and energy. The Scheimpflug system enabled quantitative cataract grading and may help predict phacodynamics in cataract surgery.