Effects of Combinations of Ophthalmic Viscosurgical Devices and Suction Flow Rates on the Corneal Endothelial Cell Damage Incurred during Phacoemulsification

Abstract

We examined the effects of different ophthalmic viscosurgical devices (OVDs) and suction flow rates during phacoemulsification on the amount of ultrasound power used and damage to the corneal endothelium. In total, 48 eyes of 24 patients who underwent phacoemulsification and intraocular lens insertion with different OVD settings in the left and right eye between February and August 2018 were examined retrospectively from medical records. Each of the following types of OVDs was used in either the right or left eye of each patient: a viscoadaptive OVD (V group) or a combination of dispersive and cohesive OVDs (soft-shell technique; S group). There was no significant difference in the lens nucleus hardness between the two groups. A 2.4 mm transconjunctival scleral incision was made, and phacoemulsification was performed by the same surgeon. The cumulative dissipated energy (CDE) and ultrasound time intraoperatively were compared between the two groups. The CDE was significantly larger in the V group (9.9 ± 4.6) than the S group (6.4 ± 3.0; p=0.006). The reduction rate of the endothelial cell density at the center of the cornea was significantly higher in the V group (4.1% ± 6.7%) than the S group (0.3% ± 4.5%; p=0.03) at 1 week postoperatively. Both groups had a good postoperative course. There was less corneal endothelial damage with the soft-shell technique combined with a normal flow setting than the viscoadaptive OVD combined with a low flow setting.

Cumulative Dissipated Energy (CDE) in Three Phaco-Fragmentation Techniques for Dense Cataract Removal

“…Other factors can decisively contribute to decreasing postoperative endothelial cell loss, such as fluidics and instrument manipulation within the anterior chamber. 15,16 Also, other variables have been described to contribute to reducing the endothelial cell count postoperatively, including the anterior chamber depth, axial length, and intraocular lens design and location. In this regard, Khalid [17][18][19][20][21] measured the impact of such factors on endothelial injury after a phacoemulsification procedure and suggested that the phaco-chop technique is superior in energy efficiency.…”

Comparative anatomical outcomes of high-flow vs. low-flow phacoemulsification cataract surgery: A systematic review and meta-analysis

“…We initially identified a total of 1,111 records through the systematic search, and after screening the study titles and abstracts, 12 potential articles (4,(9)(10)(11)(12)(13)(20)(21)(22)(23)(24)(25) were evaluated for final eligibility. Of these potential records, we excluded two studies which were not designed as randomized controlled trials (23,24), one study lacking comparisons between high-flow and low-flow phacoemulsification cataract surgery (25), and three studies without final reports (20)(21)(22). Ultimately, in this systematic review and meta-analysis, we only included six reports (4, 9-13), with a total of 477 participants from six RCTs.…”

A Shape Memory Polymeric Shield for Protecting Corneal Endothelium During Phacoemulsification

“…At present, it is generally accepted that the methods to reduce corneal endothelial damage caused by phacoemulsification include: (1) control of diabetes mellitus, 5 (2) the “soft shell” technique using low molecular weight viscoelastic devices, 6 and (3) reasonable setting of phaco-dynamic parameters. 7 , 8 However, the effects of the above measures are relatively limited, especially for those with pre-operatively existed endothelial diseases.…”