Visual outcomes and prognostic factors in patients with open globe injuries managed by Vitrectomy

Background: Ocular trauma refers to any injury to the eye. Mechanical trauma to the eye is subdivided into open and closed globe injuries. An open globe injury is defined as a full thickness wound of the eye wall and intraocular structures. The annual global incidence rate is 3.5/100000 persons. The Ocular Trauma Classification group has developed a classification system based on Birmingham Eye Trauma Terminology (BETT) and features of globe injury at initial examination. Objective: To assess risk factors prognosticating final visual outcome of post vitrectomy patients with open globe injuries. Methods: The patients with open globe injuries of all age groups on follow up for atleast6 months were included in the study. Patients were assessed by clinical examination, indirect ophthalmoscopy, X-Ray/CT scan, B scan in cases with opaque media, timing of Pars planavitrectomy, final visual outcome and retinal reattachment. Patients underwent primary repair followed by vitrectomy depending on type, severity, duration of trauma and were followed up at 1week,1month,2 months and 6months post vitrectomy. Results: The study population consisted of 75 males and 3 females, ratio of male: female was 25:1 with mean age of 20.9±7.16 years. Time duration from primary repair upto vitrectomy was <15 days in 34 (43.65%), anterior chamber was maintained in 63 (80.8%) eyes, relative afferent pupillary defect was present in 12 (15.4%) eyes. Mean visual acuity showed significant improvement from 2.26± 1.82logMAR (Hand movements) preoperatively to 1.76± 1.39 logMAR (p=0.014) at 1 month, 1.51±1.071 logMAR (p=0.007) at 2 months, 1.23±0.96 logMAR (6/96) (p<0.001) at 6 months. Retinal detachment was present in 10 (12.8%) eyes and showed poor visual outcome compared to rest 68 (87.1%) of eyes with no retinal detachment (p=0.01) which was statistically significant. Out of 78 eyes, 1 (1.3%) eye presented with vision of 6/18, 2 (2.6%) eyes with 6/36, 20 (25.6%) eyes with finger counting 1 metre, 32 (41.0%) eyes with hand movements, 23 (29.5%) eyes perception of light. Postoperatively at the end of 6 months 17 (21.8%) eyes had 6/6-6/9 vision, 13 (16.7%) eyes had 6/12-6/24 vision,16 (20.5%) eyes had 6/36-6/60, 11 (14.1%) eyes had finger counting at 1 metre, 12 (15.3%) eyes had hand movements, 8 (10.3%) eyes had perception of light and only one patient remained with no light perception as he presented with optic nerve avulsion preoperatively. Conclusion: Good preoperative visual acuity had good prognosis, but poor visual acuity did not correlate with poor visual outcome, which means that with vitrectomy the prognosis could improve in patients with lower initial visual acuity.