Role of Cold Balanced Salt Solution (BSS) in the Prophylaxis of Cystoid Macular Edema After Cataract Surgery: A Prospective Randomized Study

Purpose: To evaluate the postoperative effect on central retinal macular thickness of a cooled irrigating eye solution used during cataract surgery. Patients and methods: In this prospective, single-center study, 100 eyes of 50 patients (26 males and 24 females) were evaluated with spectral domain optical coherence tomography (SD-OCT) before and after phacoemulsification for senile cataract. Eyes were randomly divided into two groups based on the irrigating solution used during surgery: Group 1, 50 eyes received intraoperative irrigating solution at room temperature (~20.0±0.1°C); and Group 2, 50 fellow eyes received cold intraoperative irrigating solution (2.7±0.1°C). Changes in central macular thickness (CMT) were evaluated in both groups by SD-OCT macular raster scan for the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields and total macular volume, performed pre-surgery, and 1 and 4 weeks post-surgery. Results: Despite there being no significant differences in variables between the two groups preoperatively, significant increases in CMT were observed at 1 week after surgery in both groups (p=0.02 and p=0.03, respectively), as well as in total macular volume (p<0.0001 and p=0.02, respectively). Inter-subgroup analysis showed a significant reduction in CMT (p=0.03) and total macular volume (p=0.001) at 1 week post-surgery in Group 2 compared to Group 1, whereas no significant differences were observed at 4 weeks. Conclusion: The use of a cooled irrigating eye solution during phacoemulsification may be beneficial in preventing the possible development of postoperative macular thickening. Further clinical studies may support this finding.