Torsional diplopia in Graves' orbitopathy. Three case reports.

Torsional diplopia may frequently accompany Graves' orbitopathy and is often not recognized. Some patients with manifest cyclotorsion do not complain of torsional diplopia because it is concealed by the large vertical and/or horizontal deviation. Torsional diplopia can occur spontaneously or appear after decompression or strabismus surgery. We discuss some interesting points arising from three cases. This will be followed by a discussion of the literature on the pathogenesis of cyclodeviation in Graves' orbitopathy.

A protocol for extraocular muscle surgery after orbital floor fracture ("blow-out")

PURPOSE: If, after primary repair of an orbital fracture by maxillo-facial surgeons, diplopia persists, extraocular muscle surgery may be necessary. It was the purpose of this study to examine proposed surgical treatment in these cases to determine their efficacy. SUBJECTS AND METHODS: We analyzed, retrospectively, the files of 14 patients who were treated in our strabismological department for persistent diplopia caused by injury to the extraocular muscles and/or to the surrounding structures. The aim of our treatment protocol was to restore comfortable binocular single vision in primary position and downgaze. The selection of the surgical procedure depended on the deviation in primary position and on the degree of ocular muscle imbalance. Surgery consisted of recession of the inferior rectus muscle of the affected eye in 4 cases, resection of the inferior rectus muscle of the affected eye in 4 other cases, and large recessions of the vertical muscles of the contralateral normal eye in 6 cases. RESULTS: In all 14 patients, we obtained the desired comfortable field of binocular single vision, considered "good" (20 degrees up to 30 degrees downgaze) or "satisfactory" (a useful field). In 11 cases this was achieved in one procedure. Two patients needed a reintervention because of initial overcorrection, and one patient for an initial undercorrection. All 14 patients had a "good" or "satisfactory" final result (useful binocular single vision). CONCLUSIONS: When extraocular muscle surgery is necessary, we recommend in patients with limited forced elevation, recession of the taut rectus inferior muscle; in patients with the clinical characteristics of an inferior rectus palsy, a resection of this muscle; and in cases with a normal or only slightly limited forced duction test, weakening the contralateral synergists.

Examination, registration and analysis of clinical expressions of DVD.

The clinical appearance of dissociated vertical deviation (DVD) can be modified by the presence of other vertical deviations. This may be one of the reasons of relatively late diagnosis (sometimes even only after a first strabismus operation). If the DVD is not recognized preoperatively, this can lead to unexpected failure of the strabismus operation, with cosmetically unacceptable vertical deviations. The key to early diagnosis is a meticulous observation with special attention to differences in vertical deviations on right and left eye fixation in primary position and in levo- and dextroversion, using the alternating cover test. This is relatively easy and non-invasive. The authors propose a method for registration and analysis of the results. This method leads in most cases to a reliable diagnosis of the different components of the vertical deviation. The authors illustrate this method in 82 patients. In the large majority, the method presented allowed them to evaluate the respective importance of each component. Their sample illustrates convincingly the wide variety of clinical expressions of DVD. Only six patients presented a DVD without associated vertical deviations. In many cases the DVD was less important than the associated vertical deviations. This explains the difficulty of diagnosis of DVD in many cases.

Surgery on the extra-ocular muscles after orbital fracture.

We analyzed the files of 61 patients presenting with diplopia due to orbital fractures. Thirty-four patients needed a primary orbital reconstruction and this diminished the complaints of diplopia in most cases. In only 5 cases additional ocular surgery on the extra-ocular muscles was indicated. Of the 27 patients who did not require orbital surgery, 5 underwent extra-ocular muscle surgery to diminish diplopia. We present our guidelines for treatment, based on forced duction testing, ocular motility, primary position and field of binocular single vision.

Postoperative diplopia, also in children.

Permanent diplopia caused by strabismus surgery can also occur in children. In certain cases we see an analogy with the feared and well known persistent diplopia that can occur after anti-suppressive therapy. This article discusses some of these cases and their treatment.

Basic principles for strabismus reinterventions.

Fibro-elastic and mechanical factors are more important in reinterventions than in traditional strabismus surgery. It is imperative to detect them preoperatively and intraoperatively. For this purpose, the patient's personal history and complaints are analysed and some specific examination techniques are discussed such as the intraoperative eye position, the forced duction test, the muscle elasticity test and the spring back test.

Primary exodeviations. Surgical results of 94 patients operated since 1983.

Surgical results of 94 patients with primary exodeviation operated since 1983 are presented. Seventy-five patients where treated bilateral rectus externus muscle recession and 19 patients with recession of rectus externus combined with resection of rectus internus muscle. Both techniques have equal results.