Comparison of corneal changes after phacoemulsification using BSS Plus versus Lactated Ringer's irrigating solution: a prospective randomised trial

Abstract

Background/aims: To compare two intraocular irrigating solutions, Balanced Salt Solution Plus (BSS Plus) versus Lactated Ringer's (Ringer), for the preservation of corneal integrity after phacoemulsification.

Methods: 110 patients undergoing phacoemulsification were randomised to either BSS Plus (n=55) or Ringer (n=55) as the irrigating solution. Patients were examined at baseline and at 1, 8, 15, 30 and 60 days postoperatively. Evaluations included specular microscopy to evaluate endothelial cell density (ECD) and endothelial cell size variability (CV), and corneal pachymetry for central corneal thickness (CCT) measurement.

Results: Groups were well balanced regarding baseline ECD, CV and CCT (p>0.05). There was no statistically significant difference between ECD reduction in group BSS Plus 13.1 ± 2.0% and Ringer 9.2 ± 1.9% (p<0.05) at day 60 or in any study visit. There was no statistically significant difference between CV increase in group BSS Plus 23.0 ± 3.0% and Ringer 20.2 ± 4.0% (p<0.05) at day 60 or in any study visit. CCT was significantly increased (p<0.05) at 1, 8, 15 and 30 days postoperatively, returning to baseline at 60 days in both groups. There was no significant difference in CCT increase in both groups at any visit. Interestingly, there were statistically significant correlations between ECD loss and phacoemulsification time (p<0.0001) and ECD loss and irrigation solution volume (p<0.0001) in the Ringer group, but not in the BSS Plus group.

Conclusions: Ringers solution was similar to BSS Plus for corneal preservation in atraumatic cataract surgery. However, our study demonstrates that there is a trend towards lower postoperative endothelial cell density for surgeries with longer phacoemulsification time and higher irrigation volumes if Ringer is used. Trial registration number NCT00801358.

Figure 1

Specular microscopy picture illustrating the ‘centre method’ used for corneal morphology analysis in patients from Balanced Salt Solution Plus and Ringer groups in all study periods.

Figure 2

(A) Endothelial cell density, (B) central corneal thickness and (C) central corneal endothelial cell size variability changes after surgery plotted against follow-up time (days 1, 8, 15, 30 and 60). Filled grey circles connected by grey lines represent data from the Lactated Ringer's group, while unfilled circles connected with dashed lines are from the Balanced Salt Solution Plus (BSS-Plus) group. Error bars are the 95% confidence limits of the mean. Note that there is no statistically significant difference between the two groups at any study visit with respect to the three parameters.

Figure 3

Endothelial cell density change to baseline at 60 after surgery plotted against phacoemulsification time in groups Balanced Salt Solution Plus (BSS-Plus) (A) and Ringer (C); and surgical irrigation volume in the BSS-Plus (B) and Ringer group (D). Circle, results from each patient; lines, best linear fit. No statistically significant correlation was found in the BSS-Plus group, but a statistically significant correlation was found in Ringer.