Anterior segment optical coherence tomography in intracorneal foreign body

Evaluating Depth and Width of Corneal Wounds Using Anterior Segment Optical Coherence Tomography After Foreign Body Removal

PURPOSE

To determine corneal foreign body (FB) location together with corneal wound depth and width by using anterior segment optical coherence tomography (AS-OCT) after uncomplicated FB removal.

METHOD

This prospective study was conducted with patients injured by a superficial metallic corneal FB. Under slit-lamp examination, after determining its location, the FB was removed with a 27-G needle. The depth and width of the corneal wound and the thinnest stromal thickness at the wound site were measured initially using AS-OCT. Measurements were repeated to assess the wound healing process at one week and at two months following FB removal.

RESULTS

Totally, 63 eyes of 63 patients were included in this study. The average age was 35.8 ± 11.0 years, and 96.8% of the patients were men. In terms of location of the FBs, 26 (41.3%) were in the central region, 21 (33.3%) were in the paracentral region, and 16 (25.4%) were in peripheral regions. The mean depth and width of the corneal wounds were 117.0 ± 42.5 µm and 332.9 ± 99.4 µm, respectively. The mean percentage of corneal wound depth was 18.9 ± 6.1%. In 20 patients who presented for follow-up, it was observed that the width of the wound increased and the thinnest stromal thickness at the wound site decreased over the two months.

CONCLUSION

The AS-OCT findings of the present study showed that the corneal FBs generally affected the anterior cornea with less than approximately 0.2 mm depth and 0.5 mm width. In addition, FBs were commonly located in the central and paracentral cornea.

Keratitis Treatment by Removal of Concealed Retrocorneal Plant Foreign Body

Purpose: We report a case of keratitis that improved after removal of a causative plant foreign body from below the posterior surface of an opaque cornea. The foreign body was revealed by anterior segment optical coherence tomography (AS-OCT) and gonioscopy.Case summary: A 79-year-old woman was referred with an impression of left-eye keratitis; the eye had been injured by a branch of a tangerine tree 1 month prior. She had been given the usual topical antibiotics by a local clinic, but they were ineffective. At her initial visit, her visual acuity was only hand motion in the left eye; slit-lamp examination revealed a 3 × 3-mm corneal infiltration with a hypopyon in the anterior chamber. Despite administration of strong topical antibiotics on an hourly basis, the corneal lesion worsened. AS-OCT and gonioscopy revealed a small foreign body below the posterior surface of the cornea; this was surgically removed. The corneal opacity and corneal epithelial defects dramatically improved, and the hypopyon disappeared.Conclusions: The possibility of a residual foreign body should be considered if trauma precedes infectious keratitis that does not improve with conventional treatment and the posterior surface of the cornea is not visible because of corneal opacity. In such a case, AS-OCT and gonioscopy can be useful.

Retrospective Evaluation of Corneal Foreign Bodies with Anterior Segment Optical Coherence Tomography

Objectives:

To assess the anterior segment optical coherence tomography (AS-OCT) findings of various types of corneal foreign bodies.

Materials and Methods:

The medical records of patients with corneal foreign body were retrospectively analyzed. Patients who underwent anterior segment photography and Spectralis AS-OCT (Heidelberg Engineering GmbH, Germany) imaging were included.

Results:

The AS-OCT findings of 22 eyes of 20 patients with corneal foreign body were reviewed. The mean age was 34.9±14.98 years (range, 15-71) with a female/male ratio of 4/16. The mean best corrected visual acuity at presentation was 0±0 LogMAR (range, 0-0). There were 18 metallic, 3 organic (chestnut burr), and 1 chemical clay foreign bodies. The metal materials demonstrated hyperreflectivity with a mirror effect. Chemical clay, which is an opaque material, had a hyperreflective appearance. Chestnut burr is an organic foreign body with a feather-like pattern and was not detected with AS-OCT.

Conclusion:

AS-OCT is a valuable non-invasive tool to define the characteristics of foreign bodies, as well as decide the proper treatment method and monitor patients with corneal foreign bodies.