Characterization of deeply embedded corneal foreign bodies with anterior segment optical coherence tomography

Anterior segment optical coherence tomography (AS-OCT) in strabismus following trauma

We describe 3 cases of ocular trauma that presented with strabismus. Anterior segment optical coherence tomography was used to delineate the morphology of extraocular muscle insertions and proved helpful in diagnosis and management.

Clinical Applications of Anterior Segment Optical Coherence Tomography: An Updated Review

Since its introduction, optical coherence tomography (OCT) has revolutionized the field of ophthalmology and has now become an indispensable, noninvasive tool in daily practice. Most ophthalmologists are familiar with its use in the assessment and monitoring of retinal and optic nerve diseases. However, it also has important applications in the assessment of anterior segment structures, including the cornea, conjunctiva, sclera, anterior chamber, and iris, and has the potential to transform the clinical examination of these structures. In this review, we aim to provide a comprehensive overview of the potential clinical utility of anterior segment OCT (AS-OCT) for a wide range of anterior segment pathologies, such as conjunctival neoplasia, pterygium, scleritis, keratoconus, corneal dystrophies, and infectious/noninfectious keratitis. In addition, the clinical applications of AS-OCT (including epithelial mapping) in preoperative planning and postoperative monitoring for corneal and refractive surgeries are discussed.

Retrieval of deep corneal stromal wooden foreign body using vitreoretinal foreign body forceps as scoop: An innovative technique

A 55-year-old woman presented with a stromal wooden foreign body (FB) in the left cornea. The deep corneal stroma wooden FB was removed using vitreoretinal FB forceps as a scoop. In this innovative technique, a 26-gauge needle was used to open the track of the wooden FB. The FB was trapped in the concavity of one limb of the vitreoretinal FB forceps. The vitreoretinal forceps were gradually withdrawn and the FB was removed. The patient was treated with gatifloxacin and voriconazole six times, and atropine 1% three times daily. The patient did not develop infiltrate or hypopyon in 2 weeks. After 2 weeks, gatifloxacin and voriconazole were reduced to four times a day; and atropine to two times a day. After 6 weeks topical medication was stopped. The patient achieved a best-corrected visual acuity (OS) of 6/9 at 8 weeks and maintained it through 7 months of follow-up.

Anterior segment optical coherence tomography characteristics and management of a unique spectrum of foreign bodies in the cornea and anterior chamber

Purpose

To report anterior-segment optical coherence tomography (ASOCT) characteristics of different types of corneal and anterior chamber (AC) foreign bodies (FBs) and their usefulness in diagnosis and management.

Methods

This is a retrospective descriptive clinical study involving 11 eyes of 11 patients who presented at the outpatient department of a tertiary ophthalmic care center from January 2017 to January 2022. All patients had a diagnosed or suspected corneal FB. All participants underwent a comprehensive ophthalmological examination, followed by slit-lamp photography and ASOCT. FB removal was done where required by an external, internal, or combined approach.

Results

The mean age of patients was 28.2 (7-53) years. Ten were male, and one was female. Seven patients had a definitive positive history of injury; in one, there was a history suggestive of trauma, one had the post-operative complication of scleral buckling surgery, and two patients had a history of insect fall in the eyes. Three patients had acute, four had sub-acute, and four had chronic presentations. Descemet's membrane (DM) breach was suspected in three cases of deep FB, which was later confirmed on ASOCT. In two cases, DM was presumed to be intact clinically, but ASOCT showed an AC penetration. The FB was removed in seven patients, one via slit-lamp, one via an external approach, two via an internal approach, and three via a combined approach.

Conclusion

ASOCT facilitates non-invasive rapid imaging of ocular tissue at various depths, provides an accurate assessment of FB characteristics, and thereby serves as an additional tool in our armamentarium for diagnosis and management of deep corneal and AC FBs.

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.

Role of AS-OCT in Managing Corneal Disorders

Optical coherence tomography (OCT) is analogous to ultrasound biometry in the cross sectional imaging of ocular tissues. Development of current devices with deeper penetration and higher resolution has made it popular tool in clinics for visualization of anterior segment structures. In this review, the authors discussed the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Further, recent developments in the application of the device for pediatric corneal disorders and extending the application of OCT angiography for anterior segment are introduced.

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.

Comparison of Different Types of Corneal Foreign Bodies Using Anterior Segment Optical Coherence Tomography: A Prospective Observational Study

PURPOSE

The present study highlighted the value of anterior segment optical coherence tomography (AS-OCT) for different types of corneal foreign bodies in humans.

METHODS

This study was a prospective observational study. The patients included were divided into two groups. If the patients were directly diagnosed based on eye injury history and slit-lamp examination, then they were assigned to Group A. Otherwise, the patients were assigned to Group B. We compared and described the characteristics of the corneal foreign body in both groups using AS-OCT.

RESULTS

From October 2017 to January 2020, 36 eyes of 36 patients (9 females and 27 males) with a mean age of 37.8 ± 11.7 years were included in the study. Patients in Group A were the majority and accounted for 72.2% (26/36). High signals on AS-OCT images were the main constituent and accounted for 92.3% (24/26) in Group A and 70.0% (7/10) in Group B. Most of the patients in Group A, 96.2% (25/26), had clear boundaries. A blurred boundary was observed in 70.0% (7/10) of the patients in Group B. The foreign bodies on AS-OCT images had key characteristics of a high signal followed by a central zone shadowing effect and a low signal followed by a marginal zone shadowing effect. Further, all of the lesions could be directly located in Group B, and 92.3% (24/26) of the patients in Group A did not have directly located lesions. Six representative cases are described in detail.

CONCLUSIONS

AS-OCT is a valuable tool in the diagnosis and management of corneal foreign bodies, especially for unusual corneal foreign body.