Purpose:
To assess the outcomes of open globe injuries that show volume loss on computed tomography (CT).
Methods:
After obtaining IRB approval 203 CT scans performed for evaluation of open globe injuries between January 1, 1999 and August 24, 2007 at the Massachusetts Eye and Ear Infirmary were reviewed in batch for presneuroence and degree of volume loss on CT scan, globe dimensions, and associated injuries. The radiologists were asked to characterize the degree of volume loss as none, mild (1-25%), moderate (26-50%), or severe (>50%). The clinical charts were reviewed for variables including age, sex, zone of injury, enucleation rate, final visual acuity, and length of follow up. Based on the average antero-posterior, transverse and inferior-superior diameters, an approximate globe volume was calculated. Statistical significance was assessed using chi-square.
Results:
Of the 203 CT scans reviewed 126 (62%) showed volume loss: 84 mild, 16 moderate, and 26 severe. The mean follow-up was 260 days. Baseline data as well as outcomes for each group can be seen in the table below. Degree of volume loss as graded by neuroradiologist correlated with the calculated approximate globe volume. The severe volume loss group was significantly more likely to require secondary enucleation than the mild volume loss group (p=0.003, odds ratio 5.8). The mild volume loss group was significantly more likely to have a final visual acuity of 20/40 or better as compared to the moderate volume loss group (p=0.036, odds ratio 3.5) and the severe volume loss group (p<0.001, odds ratio 8.8). Injuries limited to zone 1 (corneal lacerations) were more likely in the mild volume loss group as compared with the severe volume loss group (p<0.001, odds ratio 8.6).
Conclusions:
The degree of volume loss on CT scan can provide important prognostic information when evaluating severely traumatized eyes. Those with severe loss have higher rates of enucleation. Those with mild volume loss have better visual outcomes and are likely to result from more anterior injuries.