Preoperative intraocular pressure as a strong predictive factor for intraocular pressure rise during vacuum application in femtosecond laser‐assisted cataract surgery

AbstractPurposeTo evaluate the effect of preoperative intraocular pressure (IOP) and the vacuum level on IOP during femtosecond laser‐assisted cataract surgery.MethodsIntraocular pressure was measured in 40 enucleated porcine eyes by intracameral manometry prior, during and after vacuum application using the VICTUS femtosecond laser platform (Bausch&Lomb, Technolas Perfect Vision GmbH, Germany). Twenty combinations of different preoperative IOP levels (12, 16, 20 and 24 mmHg) and different vacuum levels (350–550 mbar) were investigated.ResultsMultivariate regression analysis indicated that both the vacuum level (beta = 0.138; p < 0.001) but much stronger the preoperative IOP (beta = 0.861; p < 0.001) were predictive factors for IOP rise during vacuum application. Mean IOP was 28.23 ± 3.86, 34.23 ± 3.92, 40.35 ± 4.41 and 46.82 ± 4.11 mmHg in groups with baseline IOP of 12, 16, 20 and 24 mmHg, respectively. In the 350, 450 and 550 mbar group, and mean IOP was 35.85 ± 7.85, 37.33 ± 7.90 and 39.00 ± 8.04 mmHg, respectively. Lowering the preoperative IOP by 2 mmHg and reducing the vacuum from maximum to minimum resulted in a similar reduction in IOP during vacuum application (−3.10 ± 0.79 mmHg versus −3.15 ± 0.88 mmHg; p = 0.015). Furthermore, decreasing the baseline IOP from 20 to 12 mmHg resulted in a 30.0% reduction in intraoperative IOP.ConclusionPreoperative IOP was a stronger predictive factor for intraoperative IOP rise than the applied vacuum level. Measurements and critical interpretation of preoperative IOP in a preliminary examination could help estimating the individual risk of significant IOP rise during femtosecond laser‐assisted cataract surgery and could help taking early countermeasures in selected cases. Due to the porcine ex vivo model, further studies are needed to verify these findings.