PURPOSE: To analyze orbital morphological parameters that potentially could influence the effect of decompression surgery on exophthalmos reduction in Graves orbitopathy, thus making decompression surgery more predictable. METHODS: To generate a reference database, a CT-based study was performed in 140 orbits obtained from adult patients with unaffected orbits in a European white ethnicity. The following parameters were chosen: orbital volume, globe volume, globe to orbital volume ratio, and orbital cone angle. Volumes were measured on postprocessed CT data using morphometric techniques. To define the cone angle, a 3-dimensional approach was chosen using the program Amira. RESULTS: Significant interindividual variation was found in orbital volume from 18.9 to 33.4 ml and in globe volume from 6.0 to 10.1 ml. The globe to orbital volume ratio showed a relatively broad variation from 0.25 to 0.4. Differences in the orbital cone angle from 39.7° to 65.7° were observed. CONCLUSION: The experienced large variations in orbital morphology might significantly influence the degree of exophthalmos reduction, which can be obtained by standardized decompression procedures. Based on our results, a prospective clinical study will be conducted to test our hypothesis.
PURPOSE: To analyze orbital morphological parameters that potentially could influence the effect of decompression surgery on exophthalmos reduction in Graves orbitopathy, thus making decompression surgery more predictable. METHODS: To generate a reference database, a CT-based study was performed in 140 orbits obtained from adult patients with unaffected orbits in a European white ethnicity. The following parameters were chosen: orbital volume, globe volume, globe to orbital volume ratio, and orbital cone angle. Volumes were measured on postprocessed CT data using morphometric techniques. To define the cone angle, a 3-dimensional approach was chosen using the program Amira. RESULTS: Significant interindividual variation was found in orbital volume from 18.9 to 33.4 ml and in globe volume from 6.0 to 10.1 ml. The globe to orbital volume ratio showed a relatively broad variation from 0.25 to 0.4. Differences in the orbital cone angle from 39.7° to 65.7° were observed. CONCLUSION: The experienced large variations in orbital morphology might significantly influence the degree of exophthalmos reduction, which can be obtained by standardized decompression procedures. Based on our results, a prospective clinical study will be conducted to test our hypothesis.
Authors: F Radetzki; T Mendel; H Noser; D Stoevesandt; M Röllinghoff; N Gutteck; K S Delank; D Wohlrab Journal: Surg Radiol Anat Date: 2013-04-10 Impact factor: 1.246