Correlation of lens density and phacodynamics parameters in phacoemulsification / 眼科新进展

Objective To evaluate the correlation of lens density (LD) measured by opacity lensmeter (OLM) and Pentacam with phacodynamics in patients with age-related nuclear cataract.Methods A prospective study was conducted in 78 patients (78 eyes) with age-related nuclear cataract.The lens density was measured with OLM and Pentacam respectively before operation,and the phacoemulsification kinetic parameters in phacoemulsification,including ultrasound time (UST),cumulated dissipated energy (CDE) and balanced salt solution (BSS) usage,were recorded for the analysis of the correlations of LD values with phacodynamics.Results LD measured by OLM and Pentacam was 32.83 ± 14.41 and 15.26 ±5.82,respectively.LD from OLM and Pentacam was positively correlated with both UST (r =0.645,0.807,respectively;both P ＜ 0.05)and CDE (r =0.669,0.828,respectively;both P ＜ 0.05).UST and CDE were more strongly correlated with LD from Pentacam than from OLM (Z =2.153,2.283;both P ＜0.05).Conclusion LD from both OLM and Pentacam are correlated with UST and CDE,and a stronger correlation is observed in Pentacam than OLM.

The Relationship Between the Density of Lens and Liquefaction Time Using Liquefaction Device

PURPOSE: To investigate the effect of lens density on liquefaction time by using liquefaction device (AquaLase(R), Alcon Laboratories, TX, U.S.A.). METHODS: Cataract surgery using AquaLase(R) was performed on 47 eyes. With a Scheimpflug camera, the density and thickness of lens were measured in eye of each patient preoperatively. During surgery, liquefaction time and total number of pulses were recorded. The correlation of both density and thickness of lens with liquefaction time and total number of pulses was analyzed. RESULTS: The mean density of anterior cortex, nucleus, and posterior cortex was 112.45+/-42.1 computer compatible tapes (CCT), 76.5+/-22.7 CCT, and 70.9+/-52.2 CCT, respectively. The mean thickness was 0.97+/-0.30 mm, 2.76+/-0.54 mm, and 0.81+/-0.24 mm, respectively. The mean liquefaction time was 174.8+/-108.2 seconds. The mean total number of pulses was 4799+/-3007.There was no significant difference between the density of each area of lens (anterior cortex, nucleus, posterior cortex, and total lens) and liquefaction time (p>0.05), and between the thickness of each area of lens and liquefaction time (p>0.05). There was no significant difference between the density of each area of lens and total number of pulses (p>0.05), and between the thickness of each area of lens and total number of pulses (p>0.05). CONCLUSIONS: When extraction of soft to moderate density cataract was performed with AquaLase(R), liquefaction time and total number of pulse did not correlate to the density and thickness of lens.

The Effect of Phacoemulsification with Oscillation Device on the Cornea and Lens Opcatiy

PURPOSE: To access the effect of phacoemulsification, using Neosonix(R) (Alcon Laboratories, TX, USA), on the cornea and lens opacity. METHODS: This study involved 42 eyes of 37 patients who underwent phacoemulsification using the Neosonix from December 2005 through March 2006. We measured the density and the thickness of lenses using a Scheimpflug camera and evaluated the correlation between the density and the phaco time. To evaluate the effects of Neosonix(R) on the corneal endothelium, we measured various corneal endothelial cell parameters, including corneal endothelial cell density, corneal thickness, and morphologic changes up to two months postoperatively. RESULTS: The preoperative mean values of lens density for the anterior cortex, nucleus, and posterior cortex were 105.86+/-34.99 CCT, 82.17+/-35.14 CCT, and 77.88+/-52.98 CCT, respectively. The mean phacoemulsification time was 48.67+/-29.79 seconds and increased significantly, according to the increase of the densities of the lens nucleus and cortex (p0.05). CONCLUSIONS: The phacoemulsification time using oscillation device significantly increased as the density of the lens cortex and nucleus increased, and there was no statistically significant difference between the preoperative and postoperative values of corneal endothelial cell density.

The Relationship of the Lens Density with the Lens Thickness and the Anterior Chamber Depth

To investigate the relationship of the density change of lens nucleus and cortex with anterior chamber depth and lens thickness, we measured the anterior chamber depth, density and length of lens nucleus and cortex of 312 eyes with a Scheimpflug camera. The mean values of density of lens nucleus and cortex were 108.45+/-46.33CCT and 27.74+/-13.76CCT, respectively. The mean values of the thickness for both were 2.85+/-0.54mm and 1.29+/-0.46mm, respectively. The mean value of anterior chamber depth was 2.93+/-0.49mm. The densities of lens nucleus and cortex were increased significantly with aging, but lens thickness and anterior chamber depth were decreased. The value of anterior chamber depth changes and lens thickness changes were more rapid especially in the 5th and 7th decades compared with other groups(P<0.01), and more rapaid in the density group(100~150CCT) than other group in changing densities(P<0.05), and they were highly correlated with anterior cortex, posterior cortex, nucleus in order at each portion of lens. Both anterior chamber depth changes and lens thickness changes were more rapid in the lens cortex than those in the lens nucleus.