The trend of recovery period on postoperative eye movement in orbital blowout fractures

Abstract

To investigate the trend of restoration of postoperative eye movements after orbital blowout fractures by analyzing the percentage of Hess area ratio (HAR%). This was a retrospective study of patients who underwent orbital blow out reconstruction surgery within 28-days post injury. Eye movements were measured preoperatively and 3, 6, and 12 months post operatively by Hess chart. Orbital fractures were classified into three shapes: trap-door fracture with muscle entrapment, trap-door fracture with incarcerated tissue, and depressed fracture. Correlations between fracture shapes, regions, reconstruction implant, age and HAR% were analyzed. This study involved 125 eyes (64 right eyes and 61 left eyes) of 125 isolated orbital fracture cases (95 males, 30 females, mean age: 27.2, range 4-85 years old). Of the total 125 cases, 96 patients had orbital floor fractures, 18 had orbital medial wall fractures, and 11 had combined orbital medial wall and floor fractures. Three had trap-door fractures with muscle entrapment, 42 had trap-door fractures with incarcerated tissue, and 80 had orbital depressed fractures. The overall mean HAR% improved significantly from 76.0 pre-operatively to 95.5 post-12 months (P < 0.01). The mean HAR% in orbital floor fracture improved significantly from 76.7 pre-operatively to 92.9 and 94.7 at 3, 6 months respectively. There was a non-significant improvement in the HAR% in medial wall fractures from 83.2 pre-operatively to 89.5 at 3 months and a significant improvement to 93.2 at 6 months (p < 0.05). Orbital fractures were reconstructed with either Unsintered hydroxyapatite particles/poly l-lactide composite sheet (u-HA/PLLA composite sheet) (91 patients), a silicone silastic sheet (20 patients) a combination of sheets (7 patients) or without an implant (7 patients). There was no significant difference in the HAR% improvement between the different implants. The HAR% improvement was significantly greater in patients <18 years old than in those aged 18 or over. The HAR% is an effective method of the objective assessment of recovery after orbital fracture. Patients and surgeons should be aware that the recovery after medial wall fractures is slower than after floor fractures and continues after three months post-surgery and that a longer period of observation without further intervention may be required for medial wall fractures, whilst floor fractures are likely to have achieved their maximal recovery by three months.

Keywords: Children and adult; Orbital blowout fracture; Percentage of Hess area ratio (HAR%).