Avaliação da espessura central corneana e suas propriedades biomecânicas após facoemulsificação com córnea clara

Abstract

Purpose: To evaluate the central corneal thickness (CCT) and corneal biomechanical properties in patients prior to and following clear cornea phacoemulsification. Methods: Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF), were measured with the ocular response analyzer (ORA); and central corneal thickness (CCT) were also measured with the Oculus Pentacam, in 36 consecutive patients (47 eyes) that underwent clear cornea phacoemulsification surgery. All measurements were performed prior to surgery (Preop) and at follow-up time points: day 1 (D1), day 7 (D7) and day 30 (D30). Results: Mean and standard-deviation of ORA parameters and CCT were: CCT Preop 555.8 ± 43.7 µm, D1 690.6 ± 179.9 µm, D7 613.7 ± 107.9 µm and D30 567.1 ± 44.8 µm. CCT was higher in D1 and D7 than Preop (p < 0.05) but not in D30. CH Preop 9.6 ± 1.2 mm Hg, D1 8.1 ± 1.5 mm Hg, D7 9.1 ± 1.4 mm Hg and D30 9.0 ± 1.7 mm Hg. CH was lower in D1 than Preop (p < 0.05) but not in D7 and D30. CRF Preop 9.5 ± 1.5 mm Hg, D1 7.8 ± 1.6 mm Hg, D7 8.3 ± 1.5 mm Hg and D30 8.7 ± 1.7 mm Hg. CRF was lower in D1, D7 and D30 than Preop (p < 0.05). Conclusions: Clear cornea phacoemulsification led to a change of corneal biomechanical properties. The increase of CCT after phacoemulsification is followed by a reduction in the CRF and Hysteresis. Even when CCT and Hysteresis returns to preoperative values, the CRF remains reduced in the short-term postoperative period.