The Diagnostic Challenge of Atypical Corneal Lesions

Clinicians often encounter corneal lesions that mimic serious conditions like ocular surface squamous neoplasia (OSSN). Specifically, AS-OCT in VZV keratitis has emerged as a transformative diagnostic tool for identifying viral etiologies that lack classic dermatomal presentations. While Varicella Zoster Virus (VZV) usually presents with a clear history of shingles, atypical cases can manifest without active skin lesions, frequently leading to misdiagnosis. Consequently, using high-resolution imaging becomes essential to avoid unnecessary surgical interventions and initiate correct medical therapy promptly.

Case Analysis: Distinguishing Infection from Neoplasia

A recent case report describes a 26-year-old woman presenting with a sectoral conjunctival injection and anterior stromal opacity in her right eye. Initially, the clinical appearance suggested Corneal Intraepithelial Neoplasia (CIN). However, the patient’s five-year history of unilateral headache, alopecia, and loss of eyelashes provided subtle clues toward a viral origin. These symptoms often signal a chronic VZV infection, even in the absence of a classic rash. Therefore, the medical team utilized Anterior Segment Optical Coherence Tomography (AS-OCT) to clarify the diagnosis.

Utilizing AS-OCT in VZV Keratitis for Accurate Diagnosis

The imaging results played a decisive role in the diagnostic process. Specifically, the epithelial mapping showed that the epithelial thickness remained below the 60 µm threshold typically seen in CIN. Furthermore, the AS-OCT scans revealed subepithelial hyperreflectivity rather than the epithelial hyperreflectivity characteristic of neoplastic cells. Because the imaging lacked an abrupt transition from normal to abnormal epithelium, the clinicians successfully ruled out OSSN. Subsequently, the patient received oral valacyclovir and topical corticosteroids. Notably, the active keratitis resolved within one month, leaving only residual scarring and confirming the viral etiology.

Advantages of Epithelial Mapping

Epithelial thickness mapping offers a non-invasive way to evaluate the layers of the cornea in real-time. This technology is particularly valuable because it provides quantitative data that slit-lamp biomicroscopy cannot offer. Moreover, it allows doctors to monitor the healing process objectively. By identifying the exact depth and nature of corneal infiltrates, AS-OCT ensures that patients do not undergo invasive biopsies for lesions that respond to antiviral medication. As a result, this technology streamlines the management of complex ocular surface diseases.

Frequently Asked Questions

How does AS-OCT distinguish between VZV keratitis and CIN?

AS-OCT distinguishes these conditions by measuring epithelial thickness and reflectivity. CIN typically presents with thick, hyperreflective epithelium (often >60 µm) and an abrupt transition zone. In contrast, VZV interstitial keratitis usually shows subepithelial hyperreflectivity without significant epithelial thickening.

What is the significance of alopecia in a corneal diagnosis?

In this context, unilateral alopecia and eyelash loss are diagnostic clues for prior Varicella Zoster Virus infection. These signs suggest chronic neurotrophic changes or “zoster sine herpete,” where the virus affects the nerves without causing a visible skin rash.

Why is epithelial mapping better than a biopsy for initial screening?

Epithelial mapping is non-invasive, fast, and provides immediate anatomical detail. It helps clinicians decide if a biopsy is truly necessary by ruling out neoplastic features, thereby preventing potential surgical complications in patients with infectious or inflammatory conditions.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or a professional relationship. Always seek the advice of a qualified healthcare provider regarding any medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Alsaggaf K et al. Diagnostic Role of Anterior Segment Optical Coherence Tomography in an Atypical Presentation of Varicella Zoster Virus Interstitial Keratitis: A Case Report. Am J Case Rep. 2026 Mar 29. doi: 10.12659/AJCR.950659. PMID: 41904619.

Shousha MA et al. Diagnostic Value of Anterior Segment Optical Coherence Tomography in Ocular Surface Squamous Neoplasia. Ophthalmology. 2013;120(11):2191-2197.

Gupta N et al. Role of AS-OCT in Managing Corneal Disorders. Diagnostics (Basel). 2022;12(4):918.