Trigeminal sensory loss in orbital disease.

A study was undertaken to estimate the incidence of periorbital trigeminal sensory loss with different types of orbital disease and to determine whether the area of loss is related to the location or nature of the underlying condition. A retrospective review was carried out of the clinical case notes of patients identified from the orbital diagnostic database held at Moorfields Eye Hospital. A total of 103 patients (51 male, 52 female), aged between 11 and 84 years (median 51 years), had signs of periorbital trigeminal sensory loss at the time of investigation for orbital disease and in 14/103 (13%) this sensory loss was symptomatic. Sensory loss was due to trauma in eight cases (8%), benign orbital disease in 54 (52%), and malignant disease in 41 cases (40%). The relative frequency of recorded sensory changes is about 9% for malignant tumours, 5% for benign tumours, 4% after orbital trauma, 3% for orbital inflammatory disease, and less than 1% for orbital structural anomalies. Relative corneal hypoaesthesia occurred in 40/103 (39%) cases. Periorbital sensory loss was recorded in about 3% of patients with orbital disease and, in contrast with commonly held views, malignancy was not the most common cause of sensory loss. The affected dermatome is a useful guide to the location of orbital disease, but a poor indication of underlying pathology. Relative corneal hypoaesthesia appears unrelated to the type of disease or to its location within the orbit.