The Study of Prognostic Factors after Vitrectomy for Posterior Segment Metallic Foreign Bodies

ABSTRACT

PURPOSE: To evaluate the clinical results and prognostic factors that predict final visual outcome in eye with posterior segment metallic foreign body(FB) managed by primary pars plana vitrectomy. METHODS: Twenty-nine patients with posterior segment FBs managed by pars plana vitrectomy were reviewed retrospectively. To determine prognostic factors for visual outcomes, variables including ocular findings at presentation, initial visual acuity(VA), location, size and weight of FBs, site of entrance, location of intraretinal lesion, mechanisms of injury and FB removal time were compared with final visual acuity. RESULTS: After a mean follow up of 19.2 months, 15 eyes(52%) achieved VA of 20/40 or better and 5 eyes(17%) showed decreased VA compared to the initial VA. Prognostic factors for the final VA of 20/40 or better included the weight of FBs less than 20 mg, negative findings of retinal detachment and endophthalmitis. Prognostic factors for the final VA of 20/200 or less included the size of FBs more than 4mm, the weight of FBs more than 20 mg, intraretinal FBs, nonhammering as the mechanism of injury. CONCLUSIONS: The predictors of the final VA were the size, the weight and the location of FBs, mechanisms of injury, preoperative negative findings of retinal detachment and endophthalmitis. These factors will be helpful for planning surgery and predicting the prognosis.