The Surgical Treatment Of Complicated Cataract After Silicone Oil Infusion

Objective:To evaluate the therapeutic effect of two kinds of combined surgery on complicated cataract after silicone oil infusion; the accuracy of A-ultrasonic scan surveying their axis length and HEINE retinometer predicting the postoperative visual acuity before the operation.Methods:In this study, we selected 11 eyes of 11 cases with silicone oil tamponade underwent combined phacoemulsification, silicone oil removal through the ciliary body flat incision and intraocular lens implantation (Group A,"1+3"); selected 13 eyes of 13 cases that had received phacoemulsification at the time of silicone oil infusion were performed silicone oil removal through the ciliary body flat incision combined with secondary intraocular lens implantation (Group B,"2+2"). The cases selected criterion: After silicone oil infusion, and through more than 3 months frequent clinical follow-up, all eyes were certified that they had completely stable, reattached retina by indirect ophthalmoscopy prior to silicone oil removal. All 24 eyes were examined by A- ultrasonic scan to measure the axis length——11 eyes with lens by the mode of"Phakic,Auto + Save"; 13 eyes without lens by the mode of"Aphakic,Manual". The velocity of the beam in a silicone oil-filled vitreous cavity was changed to 987 m/s to eliminate the axial length magnification caused by the silicone oil. The SRK-T formula was used for intraocular lens calculation. Pre-operatively, all were examined with HEINE retinometer to predict post-operative visual acuity. After the operation of silicone oil removal combined with intraocular lens implantation 3 months, the actual axis length ( by the mode of"Acrylic,Auto + Save"), the final refraction and post-BCVA were measured.Results:Follow-up was more than 3 months. In Group A, the post-BCVA were 0.15±0.12 (range, 0.4 to 0.02); in Group B, the post-BCVA were 0.20±0.12 (range, 0.4 to 0.04). All were better than the pre-BCVA. The rate of post-BCVA advanced more 3 (include) rows than pre-BCVA, compared Group A and B, has statistical difference (p≈0.003, < 0.05); Group A is better than Group B. Corneal endothelium functional decompensation, residual silicone oil, lens dislocation, secondary glaucoma, and retinal detachment were not observed in any patients. The remainders of lens capsule had various degrees of opacity. The centers of IOL were clarity for lack of lens capsule. As for difficulties of operation, the group A mostly lies in CCC and phacoemulsification, the group B mostly lies in bluntly separating anterior and posterior capsular adhesion or posterior synechia.In 11 eyes with lens, the A-ultrasonic scan measurement was 25.74±1.65mm (range, 23.94 to 28.68mm), the actual axis length was 25.68±1.73mm (range, 23.60 to 28.94 mm). The difference of their measurements ranged from -0.51 to 0.36mm (average, -0.06±0.30mm), but without statistically significant (P>0.05). In 13 eyes without lens, they were 25.89±1.50mm (range, 23.86 to 28.70mm) and 25.82±1.38mm (range, 23.92 to 28.52mm) respectively. The difference of their measurements ranged from -0.45 to 0.54mm (average, -0.07±0.29mm), but without statistically significant (P>0.05), too. Two groups'mean final refraction were -0.07±1.09 diopters (range, -1.75 to 1.25 diopters) and 0.31±1.35 diopters (range, -2.00 to 2.25 diopters) respectively. The difference is not statistically significant (P>0.05).The HRVA and the post-BCVA have positive linear correlation (r=0.606, P<0.01), the linear regression equation is as follows: HRVA = 0.143 + 0.901 Post-BCVA; the rate of accordance was 58.33%, and the false-positive rate 37.50%, the false-negative rate 4.17%.Conclusions:Two kinds of combined surgery are safe, effective approaches. They have their respective difficulty of operation. Strict operating indications, selecting appropriate cases, and experienced operating skill are successful keys. The cases without obviously opaque posterior capsular in Group B can be predicated the post-BCVA before the operation via the pre-BCVA. So, Group B is better in selecting appropriate cases.After the sound speed in vitreous cavity changed to 987 m/s, it is an exact, expeditous, practical, inexpensive method that A-ultrasonic scan surveying the axis length of eyes with silicone oil tamponade——eyes with lens by the mode of"Phakic, Auto + Save"; eyes without lens by the mode of"Aphakic, Manual".HEINE retinometer is relatively reliable to predict the post-BCVA before the operation of silicone oil removal combined with intraocular lens implantation in silicone oil infusion eyes, and, can help selecting appropriate cases further, but the false-positive rate is high comparatively.