title: Compressive Optic Neuropathy and Repeat Orbital Decompression: A Case Series.
abstract: OBJECTIVE
  To characterize the presenting characteristics, preoperative clinical activity score (CAS), surgical approach, and visual outcomes in patients with thyroid eye disease undergoing repeat orbital decompression for recurrent or recalcitrant compressive optic neuropathy (CON).
  
  
  METHODS
  The medical records of patients with recurrent or recalcitrant CON undergoing repeat orbital decompressions were retrospectively reviewed. The primary outcome measures included pre- and postoperative Humphrey visual field mean deviation, visual acuity (VA) measured in logarithm of the minimal angle of resolution, color vision measured by Ishihara plates, and presence of relative afferent pupillary defect. Details of the surgical procedure and each patient's CAS at presentation were also recorded.
  
  
  RESULTS
  Six patients, 9 orbits, with a mean preoperative CAS of 3.8 were included in this review. The mean time between initial decompression and presentation to our center for recurrent or persistent CON symptoms was 8.6 years (range, 1 to 15 years). At presentation, the average Humphrey visual field mean deviation was -16.5 (standard deviation: 8.8), improving to -3.8 (2.4) postoperatively with a mean of 9.3 months follow up (mean improvement of 75%). Preoperative VA was 0.34 (0.23) LogMAR, improving to 0.05 (0.10) LogMAR with a mean follow up of 10.4 months. Pre- to postoperative comparisons of clinical measures all showed statistically significant improvement (p < 0.05). Eight eyes presented with decreased VA (any VA < 20/20), 4 with decreased color vision (any color vision < 11), and 1 with a relative afferent pupillary defect, and all these patients demonstrated improvement following repeat orbital decompression.
  
  
  CONCLUSIONS
  In patients with thyroid eye disease, symptoms of recurrent CON occurred up to 15 years following initial orbital decompression underscoring the smoldering, progressive nature of the disease. Repeat decompression that focused on the orbital apex resulted in visual improvement in all 6 patients. Despite clinical evidence of CON, the mean CAS of these patients at presentation was only 3.8, highlighting the importance of close monitoring of patients with thyroid eye disease following decompression regardless of the external manifestations of disease activity.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, U.S.A.
authors.forename: Courtney Y
authors.initials: CY
authors.lastname: Kauh
authors.forename: Shivani
authors.initials: S
authors.lastname: Gupta
authors.forename: Raymond S
authors.initials: RS
authors.lastname: Douglas
authors.forename: Victor M
authors.initials: VM
authors.lastname: Elner
authors.forename: Christine C
authors.initials: CC
authors.lastname: Nelson
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Niziol
authors.forename: Alon
authors.initials: A
authors.lastname: Kahana
mesh_terms: D019299:Decompression, Surgical; D005260:Female; D049970:Graves Ophthalmopathy / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D009915:Orbit / Q000601:surgery*; D012086:Reoperation; D012189:Retrospective Studies; D014792:Visual Acuity