Horizontal deviation as diagnostic and prognostic values in isolated fourth nerve palsy. Issue 2 (10th November 2012)

• Record Type: Journal Article
• Authors: Hata, Masayuki; Miyamoto, Kazuaki; Nakagawa, Satoko; Horii, Takahiro; Yoshimura, Nagahisa
• Is Part Of: British journal of ophthalmology. Volume 97:Issue 2(2013)
• Page Start: 180
• Page End: 183
• Publication Date: 2012-11-10
• Subjects: Eye (Globe) -- Muscles; Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjophthalmol-2012-302422
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Background/Aims: To investigate the causes of isolated fourth nerve palsy (IFNP) and the association among aetiology, prognosis and ocular deviation. Methods: A total of 126 consecutive cases of IFNP was retrospectively reviewed. According to aetiologies, all patients were classified into five groups: microvascular, congenital, decompensation of congenital, traumatic and others. We investigated the recovery rate of IFNP patients who could be followed for more than 6 months or until they recovered completely. Patients also had the magnitude of vertical and horizontal ocular deviations (prism diopter) measured in the primary eye position on the first visit. Results: Major causes of IFNP were microvascular (47%) and decompensated (33%). The rate of recovery was significantly different between microvascular IFNP and decompensated IFNP (92% vs 55%, p<0.001). There were no differences in both age of onset or mean vertical deviation between the two aetiologies (68.6±9.8 vs 65.4±13.3, 5.7±3.3 vs 7.8±7.9). However, for mean horizontal deviation, there was a significant difference between microvascular and decompensated IFNP (0.4±3.0 vs 4.9±5.6, p<0.001). Although the fourth nerve abducts the eyeball, 69 of 126 cases (55%) showed exotropia. The microvascular IFNP group included more cases of exodeviation, while the decompensated IFNP group included more cases of esodeviation (p<0.001). Conclusions: Contrary to previous thinking, the horizontal deviation of IFNP mainly showed exodeviation, and the degree of horizontal deviation is useful for making a determination between vasculopathic and decompensated IFNP. This differentiation could be critical for predicting the outcome.