AIM: To evaluate the relationship between the density values of the lens nucleus measured using Pentacam Scheimpflug imaging and torsional phacoemulsification dynamics such as the level of ultrasound energy, as well as the duration and amount of fluid used in patients with age-related nuclear cataract.

METHODS: This was a prospective observer-masked study. Pentacam Scheimpflug imaging was performed following pupil dilation. The cataracts were automatically graded from 1 to 5 using pentacam nucleus densitometry(PND), also known as Pentacam nucleus staging(PNS)software by the same observer. After phacoemulsification, total Ultrasound(U/S)time, Cumulative dissipated energy(CDE), Torsional U/S time, and Estimated fluid use were automatically calculated and displayed on the monitor of Infiniti OZiL IP phacoemulsification system. One-way analysis of variance(ANOVA)was used to assess differences between groups. The Tamhane test was used for multiple group analysis. Spearman correlation analysis was used to assess the relationship between lens density measured by PND and the dynamics of torsional phacoemulsification. P<0.05 was considered statistically significant.

RESULTS:In the present study, 125 eyes from 125 patients were evaluated. Mean age was 69.7±9.4y(range: 48-88y), and 61 men and 64 women were included. The highest and lowest values of U/S total time, torsional U/S time, CDE, and Estimated fluid use were 0.70 - 158.90s, 0.70-158.50s, 0.11-42.65, and 21-98 mL in groups, respectively. Significant differences were found among PND groups. When the relationship between phacoemulsification dynamics and PND values were evaluated, there were significant correlations between PND value and total ultrasound time(r=0.767; P<0.01), torsional ultrasound time(r=0.767; P<0.01), CDE(r=0.758; P<0.01), and amount of fluid used(r=0.602; P<0.01).

CONCLUSION:An objective degree of nucleus density obtained by PND scoring before cataract surgery may allow antecedent determination of intraoperative phacoemulsification parameters. Thus, individualized phacoemulsification parameters should be developed for each patient. This will lead to the use of a smaller amount of phacoemulsification energy, resulting in decreased in endothelial cell loss, quicker and better visual healing, and less steroid use.