Occult globe perforation during posterior sub-tenon injection diagnosed by ultrasound biomicroscopy

Abstract

Inadvertent globe perforation during posterior sub-tenon (PST) injection is rare, and the use of ultrasound biomicroscopy (UBM) in the diagnosis of occult globe perforation is not reported yet in the literature. We hereby intend to discuss the case of a 42-year-old male who presented with left eye loss of vision following PST triamcinolone acetate (TA) injection. On examination, right eye vision was 20/20 and it was 20/120 for the left eye. Fundus examination of the left eye showed a whitish fluffy mass like preretinal lesion over the macula with vitreous haze. The patient was thoroughly investigated for intermediate and posterior uveitis. However, all reports turned out to be within the normal limits. The 360° UBM scan of the left eye showed well-defined hypoechoic scleral tract suggestive of globe perforation at 2 o'clock position. The, whitish preretinal mass in the left eye was suspected to be intravitreal TA deposit following an inadvertent globe perforation during the posterior sub-tenon TA injection. UBM can be considered important diagnostic aid in ruling out possibility of occult globe perforation in certain circumstances.

Keywords: Occult globe perforation; posterior sub-tenon injection; ultrasound biomicroscopy.

Figure 1

(a) Color fundus photo of the left eye showing significant vitreous haze with whitish mass over macula (black arrow), (b) ultrasound biomicroscopy radial scan of left eye at 2 o’clock position showing well-defined hypoechoic scleral tract with conjunctival bleb (blue arrow)