Seidel Test - Unveiling the Visual Perception Assessment

Introduction:

The eye produces certain fluids, and aqueous humor is a significant one among them. Aqueous humor is a clear water-like liquid similar to blood plasma. It is usually present in the front region of the eye. It helps nourish the eye, keeping it inflated. Moreover, it contributes nutrition to the eye while maintaining the eye's ocular pressure system. In certain pathological conditions, there can be leakage of aqueous humor. The leakage might occur due to many scleral (white part of the eye) and corneal (transparent part) disorders like post-surgical leak, corneal degeneration, corneal perforation, and post-trauma effects.

What Is the Seidel Test?

The Seidel test is an assessment used for the identification of full-thickness defects related to the cornea or sclera. This works by revealing any leakage of the aqueous humor (clear fluid inside the front region of the eye). So, this test is typically used to evaluate the presence of aqueous humid leakage in the aqueous humor-filled area inside the eye between the cornea’s innermost surface and the iris, called the anterior chamber of the eye.

What Are the Indications of the Seidel Test?

The considerations for the use of the Seidel test include the following:

• Identification of any ocular leak following injury to the globe (front sensory organ).

• Determination of full-thickness depth of scleral and corneal lacerations.

• Evaluation of corneal perforation in cases of trauma, infection, and injury.

• To affirm effective wound closure in intraoperative and postoperative settings.

Moreover, this test is generally indicated for any suspicion of trauma associated with a concern for leakage in the eye. The following conditions increase the risk of potential ocular trauma and leakage.

• Lacerations through eyelids.

• Pupil defects.

• Shallow anterior chamber (front part) of the eye.

• Blood in the anterior chamber, or front region.

• Bullous subconjunctival hemorrhage (minimal amount of bleeding beneath the conjunctival region).

• Post-surgical risks for the ocular leak.

• Corneal perforation (an anomaly in the cornea occurring due to any damage to the corneal surface).

What Is the Principle of the Seidel Test?

Certain defects from injury, trauma, surgery, and infection in the sclera or cornea can influence and affect the integrity of the globe of the eye. Such defects include lacerations, perforations, infections, and surgical incisions concerning the cornea and sclera. The depth and comprehensiveness of the evaluation serve an essential role in the effective management and favorable prognosis of cases of corneal and scleral defects. The full-thickness defects of the sclera and cornea can result from an open injury of the globe, providing an outlet for the leak of the aqueous humor.

The Seidel test helps assess the leakage of vitreous or aqueous humor under cobalt blue light following the installation of the fluorescein dye. So, after applying the fluorescein dye to one’s eye surface, the dye appears green under cobalt blue light under precautionary measures. The leakage of aqueous humor from scleral or corneal defects typically dilutes the fluorescein dye, resulting in a dark blue-colored stream. Therefore, this blue stream represents a positive Seidel test.

How Does the Seidel Test Work?

The Seidel test is a quite simple and effective method for detecting leakage and perforations of the eye’s front structures, especially the sclera, and cornea. This test works by following the process.

• The application of fluorescein dye on the eye surface.

• Observation under cobalt blue light.

• Detection of any leak or perforation by the color changes and dispersion pattern.

• Assessment.

• Diagnosis and treatment.

Technique:

• The slit lamp is prepared, and the individual is placed at the slit lamp.

• The application of topical anesthetic agents follows this.

• The area of the suspected ocular leak is made dry by means of a cotton tip applicator or cellulose sponge.

• Then, the healthcare provider applies fluorescent dye to the suspected leak area. Fluorescein is orange to red in color and turns green under blue light on dilution.

• When instilled into the eye, the fluorescein dye is absorbed by the defects of the cornea, including laceration and abrasions.

• Here, the defect is generally envisioned under a cobalt blue light source. The rate of flow is eventually noted.

• For cases like postoperative wounds, the doctors apply gentle pressure to the surrounding defect areas to assess the flow.

• The Seidel test is usually done with intense caution. Doctors avoid such tests if there are complications, like the voiding of intraocular substances.

What Are the Contraindications of the Seidel Test?

The contraindications of the Seidel test include the following conditions.

• Obvious globe rupture and degeneration.

• Obvious corneal perforation.

• Hypersensitivity to fluorescein.

• Full-thickness eye lacerations.

What Is the Positive Seidel Test?

The Seidel test is beneficial for identifying tiny abrasions and leaks that seem invisible to the naked eye. It is a rapid and reliable approach to assessing the integrity of the eye's surface. A positive seidel test signifies the presence of a perforation or leak in the interior and front structures of the eye, typically the sclera and cornea. The positive test is a significant verdict, suggesting a breach in the protective barriers of the eye. This helps diagnose various eye conditions.

How Is Seidel Test Positive Managed?

The ophthalmologists treat the positive Seidel test based on the defect's size, etiology, and site. The corneal and scleral defects resulting from infection and surgical incisions are treated accordingly, with or without additional surgeries. However, the full-thickness perforation and laceration of the sclera or cornea resulting from a traumatic open globe injury require prompt treatment, constituting surgical repair.

The other treatment measures include the following.

• Pain control medications.

• Tetanus prophylaxis.

• Topical antibiotic drops.

• Antibiotic medications.

• A small surgical incision with bandaged contact lenses.

Conclusion

The Seidel test is a typical diagnostic method used in the field of ophthalmology. This test helps assess the integrity of the globe or the eye's corneal surface by evaluating the aqueous humor's presence or flow. Here, the healthcare providers apply the fluorescent dye and look for patterns of dispersion and color changes. The positive Seidel test aids in assessing several eye health conditions like ulcers, abrasions, and lacerations.