Fluctuations in intraocular pressure before and after femtosecond laser pretreatment for cataract surgery

PURPOSE To analyze the intraocular pressure (IOP) variations during femtosecond laser pretreatment for cataract surgery.

DESIGN Prospective nonrandomized observational study.

METHODS IOP was measured before docking and after removal of suction ring using an Icare ic 100 tonometer on eyes scheduled to undergo femtosecond laser-assisted cataract surgery on the CatalysTM Precision Laser System. Analysis was done to find out association between post-suction removal IOP with various patient and laser parameters.

RESULTS A total of 205 eyes of 181 patients with a mean age of 66.28 ± 9.83 years were included. The median predocking and post-suction removal IOP were 17 (IQR, 14-20) mmHg and 26 (IQR, 22-31) mmHg, respectively. The median increase of 9 (IQR, 6-12) mmHg was observed in IOP from predocking to post-suction removal stage. In subgroup analysis, post-suction removal IOP was significantly higher in eyes with shallow anterior chambers ≤2.5 mm (33 mmHg; IQR 28.5-36), thicker lenses ≥5 mm (28.5 mmHg, IQR 25-34.75), and glaucoma (29 mmHg, IQR 24-35). IOP elevation was maximum in eyes with shallow anterior chambers (14 mmHg, IQR 9-16.5), followed by those with thicker lenses (11.5 mmHg, IQR 7-15) and quadrant softened pattern of nucleotomy (11.5 mm Hg, IQR 8-14). Multiple regression analysis found positive association of post-suction removal IOP with predocking IOP, nucleotomy energy, and negative correlation with anterior chamber depth.

CONCLUSION Femtosecond laser pretreatment was associated with a significant IOP rise. Patients with high baseline and predocking IOP, shallow AC, and glaucoma need better perioperative IOP control. Customization using laser parameters with lower energy consumption can help in reducing post treatment IOP.