[Diplopia complicating peribulbar anesthesia for cataract surgery and early use of MRI]. / Diplopie après anesthésie péribulbaire pour chirurgie de la cataracte: évaluation d'une nouvelle stratégie diagnostique incluant l'IRM précoce.

OBJECTIVE: To evaluate the early use of magnetic resonance imaging (MRI) for the diagnosis of diplopia following cataract surgery under peribulbar anaesthesia. STUDY DESIGN: Single centre prospective study. PATIENTS AND METHOD: From January 2003 to January 2005 every patient undergoing cataract surgery under peribulbar anaesthesia was included. Any patient spontaneously complaining of double vision on day 1 received a full ophthalmologic examination. When binocular diplopia was confirmed by a positive Hess-Lancaster test, the patient immediately underwent an MRI. RESULTS: During the two year period, 4805 patients underwent cataract surgery under peribulbar anaesthesia. Eight patients reported double vision on day 1 (0.16% prevalence). Clinical examination confirmed binocular diplopia and a positive Hess-Lancaster test identified the paralysed muscle. In 7 out of 8 patients, the MRI performed on the same day showed a T2 hyper intensity signal within the paralysed muscle, it was interpreted as inflammatory oedema following an accidental intra muscular injection of a myotoxic local anaesthetic. In one patient the MRI was normal, suggesting a preoperative undiagnosed diplopia having no relation to the peribulbar anaesthesia. CONCLUSION: A slit-lamp exam and a Hess-Lancaster test are necessary to confirm postoperative strabismic diplopia after cataract surgery. An early MRI can accurately distinguish postanaesthetic myotoxic diplopia from a preoperative diplopia revealed by the corrective cataract surgery.

Early exploration of diplopia with magnetic resonance imaging after peribulbar anaesthesia.

We report the cases of five patients who have experienced postoperative diplopia after cataract surgery under peribulbar anaesthesia and in whom orbital Magnetic Resonance Imaging was performed immediately after the diagnosis. In four patients, the imaging study showed a T2 hyper-intensity signal and swelling of one extraocular muscle that was interpreted as oedema. Therefore, these cases were most probably a result of an accidental i.m. injection of local anaesthetics. In the other patient, the imaging study revealed no abnormality.