The Anterior Segment Optical Coherence Tomography (ASOCT) is a new imaging modality that allows cross-section imaging of the anterior segment at high resolution. This can be performed even in presence of corneal opacification.¹ We report a case of penetrating corneal injury in a professional falconer. Following primary repair, the anterior segment was assessed post-operatively using ASOCT, which revealed the extent of anterior segment injury despite the presence of corneal oedema.

Case report

A 23-year-old falconer presented with a penetrating injury to his left eye sustained while flying a red kite (Milvus milvus). The bird’s “talon” had caught the eye on landing. Examination showed hand-movements vision, a 3.5 mm nasal corneo-limbal perforation with iris prolapse, hyphaema and clear lens. The intraocular pressure (IOP) was 12 mm Hg.

Surgery was performed immediately. In addition to the pre-operative findings, vitreous prolapse was noted. Surgery involved abscission of iris, anterior vitrectomy and corneal suturing with 10–0 nylon; intravitreal vancomycin, amikacin and amphotericin were injected. Post-operatively he received topical ofloxacin 0.3% and dexamethasone 0.1% for a month. At 3 weeks follow-up, left eye examination showed vision of 6/9 uncorrected, intact corneal wound with surrounding corneal oedema, quiet looking anterior chamber, distorted pupil and IOP of 25 mm Hg (fig 1A,B). Gonioscopic view was obscured due to corneal oedema. Fundal examination was normal. Anterior segment Optical Coherence Tomography (Visante™ OCT, Carl Zeiss, Dublin, California, USA) was performed, which demonstrated posterior corneal wound malposition, partial loss of iris tissue and peripheral anterior synechiae in the adjacent angle (fig 2A). In addition, ASOCT showed zonular dehiscence with vitreous prolapse and mild lens subluxation localised to the injury site (fig 2B). At 7-weeks follow-up (dexamethasone stopped 3 weeks earlier), his uncorrected vision improved to 6/6 with an IOP of 40 mmHg. Oral acetazolamide and topical antiglaucoma medications were prescribed to lower IOP. Residual vitreous in anterior chamber was now visible clinically using conventional methods.

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Figure 1

 (A) Slit-lamp photograph of left eye showing repaired corneal perforation and nasal iris defect. Assessment of anterior chamber angle and zonular damage at wound site is difficult due to corneal oedema. White dashed line shows the plane of OCT section. (B) Slit-lamp retroillumination photograph of left eye showing difficult anterior segment assessment.

Comment

ASOCT is a high-resolution, non-contact method of anterior segment imaging that uses 1310-nm light.¹ It shows the anatomical relationships of cornea, iridocorneal angle and other anterior segment structures in real time.² It enables measurement of anterior segment structures such as corneal thickness, anterior chamber depth and anterior chamber angle. In addition to preoperative and post-operative assessment, ASOCT can be used intraoperatively which can help in the intraoperative diagnosis and subsequent surgical decision making.³

In this case, ASOCT showed angle damage, zonular dehiscence and residual vitreous prolapse, and suggested residual vitreous in anterior chamber as the cause of raised IOP. Due to the presence of corneal oedema, these findings could not be determined during the early postoperative period using conventional examination methods such as slit-lamp examination and gonioscopy. Although high-frequency ultrasound biomicroscopy could have revealed such clinical information, it would be unsuitable in a case with perforating eye injury, due to the immersion method required.

Anterior segment OCT is a novel imaging modality, which is valuable in the evaluation of eye injuries and especially useful in the management of these cases where a non-invasive method of anterior segment assessment is required.