ABSTRACT
Background: Cataract surgery is one of the most frequently performed eye surgeries worldwide, and among several techniques, phacoemulsification has become the standard of care due to its safety and efficiency. We evaluated the advantages and disadvantages of two phacoemulsification techniques: phaco-chop and divide-and-conquer. Methods: PubMed, Cochrane, Embase, and Web of Science databases were queried for randomized controlled trial (RCT), prospective and retrospective studies that compared the phaco-chop technique over the divide-and-conquer technique and reported the outcomes of (1) Endothelial cell count change (ECC); (2) Ultrasound time (UST); (3) Cumulated dissipated energy (CDE); (4) Surgery time; and (5) Phacoemulsification time (PT). Heterogeneity was examined with I2 statistics. A random-effects model was used for outcomes with high heterogeneity. Results: Nine final studies, (6 prospective RCTs and 3 observational), comprising 837 patients undergoing phacoemulsification. 435 (51.9%) underwent the phaco-chop technique, and 405 (48.1%) underwent divide-and-conquer. Overall, the phaco-chop technique was associated with several advantages: a significant difference in ECC change postoperatively (Mean Difference [MD] -221.67 Cell/mm2; 95% Confidence Interval [CI] -401.68 to -41.66; p < 0.02; I2=73%); a shorter UST (MD -51.16 sec; 95% CI -99.4 to -2.79; p = 0.04; I2=98%); reduced CDE (MD -8.68 units; 95% CI -12.76 to -4.60; p < 0.01; I2=84%); a lower PT (MD -55.09 sec; 95% CI -99.29 to -12.90; p = 0.01; I2=100). There were no significant differences in surgery time (MD -3.86 min; 95% CI -9.55 to 1.83; p = 0.18; I2=99%). Conclusion: The phaco-chop technique proved to cause fewer hazards to the corneal endothelium, with less delivered intraocular ultrasound energy when compared to the divide-and-conquer technique.
ABSTRACT
This study aimed to determine the pars plana length in postmortem human eyes using advanced morphometric techniques and correlate demographics to ocular metrics such as age, sex, ethnicity, and axial length. Between February and July 2005, we conducted a cross-sectional observational study on 46 human cadaver eyes deemed unsuitable for transplant by the SBO Eye Bank. The morphometric analysis was performed on projected images using a surgical microscope and a video-microscopy system with a 20.5:1 correction factor. The pars plana length was measured three times per quadrant, with the final value being the mean of these measurements. Of the 46 eyes collected, 9 were unsuitable for the study due to technical constraints in conducting intraocular measurements. Overall, the average axial length was 25.20 mm. The average pars plana length was 3.8 mm in all quadrants, with no measurements below 2.8 mm or above 4.9 mm. There were no statistically significant variations across quadrants or with age, sex, axial length, or laterality. Accurately defining the pars plana dimensions is crucial for safely accessing the posterior segment of the eye and minimizing complications during intraocular procedures, such as intravitreal injections and vitreoretinal surgeries.
