Effect of Hansatome microkeratome suction ring on ocular structures during LASIK

Objective To evaluate the effect of Hansatome microkeratome suction on ocular structures during LASIK. Methods 105 eyes of 64 patients with myopia or astigmatic myopia were included. Before and during Hansatome microkeratome ring (Bausch & Lomb Surgical, Munich, Germany) applied using A-scan ultrasonography to measure anterior chamber depth, lens thickness, vitreous body, and axial length.All data were collected and evaluated using SPSS for Windows (version 13.0) programs. P values less than 0.05 were considered statistically significant. Results The mean age of the patients was 22.4 years (ranged from 18 to 37 years) and the mean spherical equivalent was (-4.50±1.75 )D, The anterior chamber depth, lens thickness, vitreous body and axial length ultrasound measurements before suction were (3.62±0.29)mm,(3.68±0.34)mm, (17.79±1.01)mm, (25.09±0.99)ram,and during suction were (3.76±0.26)mm, (3.52±0.26)mm, ( 17.95±1.01 )mm,25.23±1.01mm respectively. During the suction, anterior chamber depth, vitreous body and axial length increased in 0.14mm, 0.16mm and 0.14mm, there is a significant difference (P＜0.01 ) ;The lens thickness reduced in 0.15mm, there is a significant difference (P＜0.01 ). Conclusions Vacuum by a microkeratome suction ring induced a significant increased in anterior chamber depth, vitreous body, axial length, and significant decreased in lens thickness which might caused ocular structure changes. The surgeon should apply vacuum time as less as possible during surgery. Key words: Microkeratome suction;  Anterior chamber depth;  Lens thickness; Vitreous body; Axial length