RESUMO
PURPOSE: To determine the relation between overcorrection of orbital volume and ocular projection in patients with orbital trauma. MATERIALS AND METHODS: A prospective cohort study was performed of patients with enophthalmos as a side effect of orbital trauma. The sample included patients older than 18 years who required reconstruction using customized implants to treat enophthalmos with or without diplopia. The exclusion criteria were patients who had multiple or extended fractures and patients with amaurosis or a prosthetic eye. Orbital volumes were calculated and the position of the eyeball in the healthy and traumatized sockets was determined before and after installing the implant and the ratio between these variables was calculated. Two variables were identified: 1) orbital volume and 2) enophthalmos. Analysis of the estimator variables was performed, defining 3 groups: 1) healthy eye socket, 2) traumatized eye socket without implant, and 3) traumatized eye socket with implant. The Shapiro-Wilk test, paired t test, and linear regression analysis were performed. A P value less than .05 (95% confidence interval) indicated significant differences. RESULTS: Of 294 patients who underwent orbital zygomatic complex reconstruction surgery, 13 required customized implants and only 5 met the inclusion criteria. The average volumetric variation in the groups of traumatized eye sockets with and without implants was statistically significant (P < .05), overcorrecting by an average of 4.2 cm3. The average enophthalmos variation in the groups of traumatized eye sockets with and without implants was statistically significant (P < .05), projecting the eyeball by an average 1.80 mm. The ratio between the average orbital volume and projection of the eyeball was determined to be 1:0.721 (correlation, 45.6%). CONCLUSION: This study concluded that the eyeball is projected 0.7 mm for every 1 cm3 of volume added in customized orbital implants. However, additional clinical studies with larger samples should be conducted.