Incidence of ocular injury in visually asymptomatic orbital fractures.

PURPOSE: To determine the incidence of severe ocular injury in visually asymptomatic patients with orbital fractures. METHODS: Retrospective review of 241 cases of orbital fracture, of which 126 cases had ophthalmic evaluation within 1 week of injury and were included in our analysis. Fracture type, associated symptoms, and injuries were evaluated. Injuries were categorized into severe (requiring immediate evaluation), moderate (requiring evaluation within the next several days), and mild (may not require evaluation). The presence of symptoms and associated visual acuity and severity of injury were analyzed for statistical significance. RESULTS: Forty-six of 126 patients with orbital fractures were visually asymptomatic. Of these patients, none had severe injuries, 15 had moderate injuries, 23 had mild injuries, and 8 had no injuries. Of those with symptoms, 15 had severe injuries, 27 had moderate injuries, 35 had mild injuries, and 3 had no injuries. Using Fisher exact test analysis, asymptomatic patients were unlikely to have severe ocular injury in the setting of orbital fracture (p = 0.0009). In addition, visual acuity did not accurately predict the presence of severe ocular injury. CONCLUSION: Visually asymptomatic patients with orbital fractures do not have ocular injury requiring emergent evaluation.

Use of cobalt blue light in grading cataract and estimating vision loss.

PURPOSE: To test an anecdotally reported cataract grading system predictive of a 20/50 visual threshold in cataract-induced vision loss using cobalt blue light. SETTING: Hennepin County Medical Center, Minneapolis, Minneapolis VA Medical Center, Minneapolis, and Regions Hospital, St. Paul, Minnesota, USA. METHODS: Four observers evaluated pure nuclear cataracts using a standardized cobalt-blue-light protocol. Observers graded a nuclear cataract as positive if the posterior capsule was visualized with cobalt blue light and negative if the posterior capsule was not visualized. Results of the grading were compared with cataract-induced vision loss in an attempt to establish a threshold for lost visual acuity in grading cataracts with cobalt blue light. The study design was prospective observation of a cohort with a visually significant cataract. RESULTS: This study did not show a clear visual acuity threshold for cataract-induced vision loss using a standardized cobalt-blue-light protocol. Overall, 26.3% (95% confidence interval, 13.4-40.2) of all 20/40 or less dense nuclear cataracts had visible posterior capsules using cobalt blue light, with good estimated interobserver agreement. CONCLUSIONS: Although cobalt blue light is selectively absorbed by yellow pigment in an aging nuclear cataract, its ability to predict visual acuity loss due to lens opacity was limited.