The incidence of diplopia following coronal and translid orbital decompression in Graves' orbitopathy.

PURPOSE

Firstly, to assess the incidence of induced diplopia following orbital decompression in patients with Graves' orbitopathy. Secondly, to assess patient satisfaction after orbital decompression. Thirdly, to determine the factors that contribute to the variable reported incidence of diplopia complicating decompression surgery.

METHODS

We present a retrospective analysis of the alterations of ocular motility in a consecutive series of 81 patients with Graves' orbitopathy who underwent orbital decompression by either a coronal or a translid approach. We assessed patient satisfaction by a telephone survey, and we reviewed the literature.

RESULTS

Eleven patients underwent decompressive surgery for dysthyroid optic neuropathy (DON); 5 of them had a three-wall coronal decompression, the other 6 had a two-wall translid decompression. One of the 5 (20%) coronal versus 2 of the 6 (33%) traslid patients experienced worsening of their existing diplopia. Seventy patients underwent surgery for disfiguring proptosis; 41 of them had a coronal decompression and 29 had a translid decompression. Eight of the 41 coronal patients (20%) and 4 of the 29 translid patients (14%) experienced aggravation of their motility impairment. There was no statistically significant difference between these percentages (chi-squared, p > 0.05). Three of 26 coronal patients (12%) without pre-operative motility impairment developed diplopia in all directions. Twenty-five per cent needed strabismus surgery (9% multiple times). High satisfaction scores were noted after both types of orbital decompression. Through a review of the literature, several factors that may add to heterogeneous results were identified, including definition of diplopia, inclusion criteria and type of surgery.

CONCLUSIONS

Induced diplopia is seen after any type of orbital decompression (19% overall), and its incidence is determined by various factors. To facilitate comparative studies between decompression techniques, a standardised protocol for orthoptic evaluation should be developed.