The using of A-scan echography in the triple surgery treating silicone oil complicated cataract

Objective To evaluate the accuracy of the biometry using A-scan echography for the axial length (AL) of silicone oil-filled eyes,and the security of the phacoemulsification combined silicone oil removal and intraocular lens implantation.Methods Eleven silicone oil-filled eyes combined with complicated cataract in 11 patients were included in the study.The ALs of all the silicone oil-filled eyes was measured with A-scan echography before operation.The silicone oil bubble's length equals 0.644 times the length measured with the sound velocity 1 532 m.s-1.The depth of the water layer beneath the oil bubble was also included in the calculation of the AL with echography.All of these eyes underwent phacoemulsification combined with silicone oil removal and intraocular lens implantation.The deviation of the refraction between the target and the actual was assessed post-operatively. Results ALs pre-surgical measured by A-scan echography were 25.46 ±2.20mm (22.17～29.38 mm).All of the operations were performed successfully; IOLs were placed into the capsule bag.No complication took place at 6 months.The uncorrected visual acuity after operation of 8 patients' was 0.1-0.3,and of 3 patients' was 0.4-0.6.The refractive bias (described as spherical equivalent) after intraocular lens implantation was 0.77±0.32D (0.25～1.25D),4 of them ≤ ±0.5D (36％),9 of them ≤±1.0D (82％),only 2 of them (18％) was 1.25D.Conclusions The AL of eyes tamponaded with silicone oil and combined with complicated cataract can be measured reliably with A-scan echography.Phacoemulsification combined silicone oil removal and intraocular lens implantation is effective,safe and reliable method for the treating of silicone oil complicated cataract. Key words: Silicone oil;  Biometry;  A-scan echography;  Cataract;  Intraocular lens