First Author: S.Sosnovskii RUSSIA
Co Author(s): A. Kulikov E. Nikolaenko N. Haritonova
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In recent years, the number of cataract surgery has increased due to widespread cataract disease and new high tech equipment. However, cataract surgery may be accompanied by intraoperative (damage of the capsular bag with nucleus dislocation into the vitreous) and postoperative (intraocular lens (IOL) dislocation into the vitreous) complications. Developing technologies of vitreoretinal surgery (VRS) allow to treat these complications. Vitrectomy includes potentially negative effects on the retinal functions: the high frequency vibration of the cutter tip, intraocular pressure drops, intensive light of endoillumination, the impact on the retina of ultrasonic energy in phacoemulsification of the lens nucleus.
To compare bioelectrical retinal activity in cases of complicated and uncomplicated cataract surgery
The 1st group includes 18 eyes of 18 patients having history of dropped nucleus or intraocular lens dislocated into the vitreous after phacoemulsification who underwent 25 gauge pars plana vitrectomy (PPV) with lens elevation with the help of perfluorocarbon liquids. The 2nd group (control group) includes 15 eyes of 15 patients who had phacoemulsification cataract surgery without complications. Functional parameters of retina assessment by Ganzfeld electroretinography (GERG) which was recorded at baseline and on the 1st, 3d, 7th, 14th, 30th days after surgery using Tomеy EP-1000 Multifocal (Tomеy, Japan). A-wave, b-wave amplitudes were recorded in µV, a-wave, b-wave latency were recorded in ms. The paired samples t-test was used to identify the differences in a-wave, b-wave amplitudes each postop day in comparison with the baseline level, P value <0.05 was considered statistically significant.
In the 1st group baseline a-wave amplitude was 89.36±18.65 µV, in the control group a-wave amplitude was 115.5±16.59 µV, P<0.05. In the 1st group baseline b-wave amplitude was 192.93±44.01 µV, in the control group b-wave amplitude was 213.26±18.33 µV, P<0.05. in the 1st group on the 1st day after PPV the a-wave amplitude was 63.4±15.22 µV, b-wave – 147.23±36.98 µV, we observed the decrease of a-wave and b-wave amplitudes in comparison with the baseline (P<0.01). On the following days, we observed further statistically significant decrease of a-wave and b-wave amplitudes compared with baseline a-wave and b-wave level (3rd day a-wave - 79.67±12.17 µV, b-wave - 174.99±21.43 µV, 7th day a-wave - 87.81±19.67 µV, b-wave 188.4±23.56 µV, 14th day a-wave - 93.55±20.33 µV, b-wave – 199.73±24.26 µV, P<0.05). On the 30th day the recorded parameters exceeded the baseline levels, the a-wave amplitude was 95.59±19.23 µV, b-wave amplitude was 202.09±29.21 µV, (P>0.05). The dynamics of a-wave and b-wave amplitude was stable on the follow up period in comparison with baseline level in the control group.
1. Intraoperative complication of cataract surgery as nucleus or lens masses dislocated into the vitreous results significant depression of bioelectrical retinal activity in postoperative period in comparison with incomplicated cataract surgery. 2. The complex of unfavorable factors of vitrectomy proceded for elimination of nucleus or lens masses or IOL dislocated into the vitreous causes further valid depression of bioelectrical retinal activity 1-st day postop. 3. Depressed bioelectrical retinal activity as a result of pathological substrate presence in the vitreous restores to normal levels in 2 weeks postop after vitrectomy.