Abstract
Purpose :
Post-decompression strabismus and diplopia are not uncommon in Graves’ orbitopathy patients and most require either prisms or strabismus surgery to correct their vision. We sought to determine whether there are characteristics that make it more likely for patients to undergo strabismus surgery after decompression.
Methods :
We performed a retrospective review of Graves’ orbitopathy patients who underwent orbital decompression in our institution from 2010 to 2015 (IRB approved). The preoperative characteristics examined were: age, gender, disease duration, smoking history, presence of optic neuropathy, history of steroid therapy, radioactive thyroid ablation, and prior history of strabismus surgery and/or decompression. Patients were classified either as type 1 or type 2 Graves’ orbitopathy subtype as described by Nunery et al. Only patients who reported diplopia after decompression and required either prisms or strabismus surgery were included in the final analysis.
Results :
In the 63 patients that underwent orbital decompression, ten type 1 patients were identified and none of these patients reported post-decompression diplopia in primary gaze. In the 53 Type 2 patients that were identified, 19 patients required strabismus surgery while seven required prisms to treat their post-decompression diplopia. In the assessed parameters, there were no significant differences between the strabismus and prism groups within the Type 2 patients except for the prism group having more former smokers (p=.0026) and the surgery group having more patients with optic neuropathy (p=.0394)
Conclusions :
While we are limited by the retrospective nature of our study, our data suggests that Type 2 patients are more likely to require strabismus surgery especially those with compressive optic neuropathy. We hypothesize that this could be secondary to larger, scarred muscles and apex crowding that required more bony decompression and orbital strut removal resulting in strabismus too great to be corrected by prisms. Larger EOMs and strut removal have been implicated in literature to contribute to the development of post-decompression diplopia. Smoking cessation may prevent further EOM damage and reduce the need for strabismus surgery as smoking has been linked to mediate restrictive myopathy in Graves’ patients.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.