Retrospective Analysis On The Effects And Influence Factors To The Prognosis After Extraction Of Posterior Segment Located Magnetic Intraocular Foreign Bodies By Two Different Procedures

Objective:To evaluated the clinical effects and influence factors to the prognosis after extraction of posterior segment located magnetic intraocular foreign bodies by vitrectomy and non-vitrectomy procedures.Methods:Retrospectively evaluated 113 eyes of 113 patients with penetrating ocular injury complicated by posterior segment remaining of magnetic intraocular foreign body. This cilinal trial included the patients hospitalized from July 2006 to December 2010, in which 61 eyes underwent vitrectomy and extraction of the intraocular foreign body,52 eyes underwent extraction of intraocular foreign body by trans-scleral way. The correlations between the postoperaive best corrected visual acuity and the influence factors, included operation models, preoperative best corrected visual acuity, locations and size of the foreign bodies, timing of operation, traumatic conditions, retinal detachment were analyzed. Chi-square test and Mann-Whitney U test were used to evaluate these datas.Results1. The successful rate of the extraction of foreign bodies:Group A patients had a 100% extraction of the foreign bodies by vitrectomy procedures. Otherwise, group B patients had a 86.54% extraction of the foreign bodies by trans-scleral procedures.2. Preoperatively,70.49% patients form group A had a preoperative BCVA,75.0% patitents from group B had a<0.1 preoperative BCVA,occurred in 43 of 61 (70.49%) in the first-stage vitrectomy group,compared to 39 of 52 (75.00%) in the non-vitrectomy group. Whereas, for preoperative visual acuity and conditions of ocular trauma, there was no statistical significant between the patients of group A and group B.3. Forty eight eyes (78.69%) of 61 patients from group A had a postoperative BCVA more than 0.1,18 eyes (29.51%) had a postoperative BCVA more than 0.5, and statistical analysis showed a significant different (P=0.000) between preoperative and postoperative BCVA in this group. In contrast of group A patients,5 eyes (5.77%) had a postoperative BCVA more than 0.1,2 eyes (3.85%) had a postoperative BCVA more than 0.5 in group B, there was not significant difference (P=0.552). Further more, statistical analysis showed group A patients had a better postoperative BCVA than that group B patients had (Z=-6.453, P=0.000).4.For complications, its occurrence in group A patients was lesser than that in group B patients (P<0.05). Retinal detachment occurred in 4 eyes, tPVR developed in 3 eyes, vitreous hemorrhage appeared in 1 eye and 6 eyes (9.84%) underwent the second-time vitrectomy to attached the retinal. In patients from group B, retinal detachment occurred in 24 eyes, tPVR developed in 26 eyes, vitreous hemorrhage appeared in 36 eyes, endophthalmitis noted in 3 eyes and 43eyes (82.69%) underwent vitrectomy 5～20d after trans-scleral extraction of IOFB, finally, no retinal reattachment was noted in 2 eyes and 1 eye was enucleated.5. The influence factors to the prognosis in group A were as the following:length of the wound, preoperative visual acuity, operative timing, retinal detachment, endophthalmitis and zone of retinal injury.Conclusion:1. Vitrectomy is more favorable than non-vitrectomy for the extraction rate of posterior segment located intraocular foreign bodies. The postoperative visual outcome in group A was better than that in group B, complications in group A were less than that in group B.2. Vitrectomy procedures was the method of choice for patients with posterior segment located IOFB complicated with endophthalmitis or with retinal detachment.3. The influence factors to the prognosis in patients underwent vitrectomy were length of the wound, preoperative visual acuity, operative timing, retinal detachment, endophthalmitis and zone of retinal injury.4. Retinal detachment and tPVR were the leading complications following extraction of IOFB by vitrectomy, visual prognosis was poor in patients with such complications.5. In case of the appearance of endophthalmitis in patients with posterior segment located IOFB,early vitrectomy should be emphasized as early as possible.Even if do so, the postoperative visual outcomes was poor.