Anterior Segment Optical Coherence Tomography for the Tailored Treatment of Mooren's Ulcer: A Case Report

Abstract

Background: Mooren's ulcer (MU) is a rare and debilitating form of peripheral ulcerative keratitis (PUK), characterized by a crescent-shaped ulcer with a distinctive overhanging edge at the corneal periphery. If left untreated, MU can lead to severe complications such as corneal perforation and blindness. Despite various treatment approaches, including anti-inflammatory and cytotoxic drugs, as well as surgical interventions, there is no clear evidence of the most effective treatment due to the lack of randomized controlled trials. AS-OCT is a non-invasive imaging technique that provides high-resolution cross-sectional images of the anterior segment, allowing for accurate evaluation of corneal ulcer characteristics, including depth, extent, and disease progression. Methods: We present the case of a 20-year-old male patient with MU managed using a stepladder approach, which included local and systemic corticosteroids, limbal conjunctival resection, and Cyclosporine A 1% eye drops. The patient underwent consecutive AS-OCT examinations and strict follow-up to tailor systemic and topical therapy. Results: Complete healing of the corneal ulcer with resolution of the inflammatory process was achieved. There was no recurrence of the disease at the 7-month follow-up. AS-OCT demonstrated progressive reorganization and thickening of the stromal tissue until the complete recovery of stromal thickness. Conclusions: The AS-OCT imaging modality allowed for the accurate evaluation of corneal ulcer characteristics, facilitating informed decision-making regarding the use of systemic immunosuppression, surgical interventions, and local immunomodulation and providing detailed and precise assessment of disease progression. This approach enabled a tailored and effective treatment strategy for the patient and played a critical role in guiding the therapeutic approach.

Keywords: AS-OCT; Mooren’s ulcer; PUK; corneal imaging; cyclosporine A.

Figure 1

Slit lamp examination and corresponding AS-OCT section pointed out by the line across the area of interest. May (A,B). Slit lamp biomicroscopy (A) shows conjunctival hyperaemia, intense perikeratic reaction, circular paralimbal temporal thinning, and an epithelial defect. AS-OCT scan (B) reveals the absence of the epithelium, stromal thinning (residual stromal thickness of 440 μm), and stromal hyper-reflectivity. June 2023 (C,D): Resolution of the inflammatory condition was observed. The conjunctiva was normoemic with no perikeratic reaction, and the epithelial defect had been repaired (C). AS-OCT scan showed that the epithelial layer was irregular and hyporeflective but intact, filling the area of corneal thinning. The underlying stroma was hyper-reflective (D). July 2023 (E,F): Worsening of the clinical condition was observed. Severe perikeratic reaction with temporal ulceration and thinning (E). AS-OCT scan revealed the absence of the epithelial layer, significant stromal thinning (319 μm), and stromal hyper-reflectivity (F).

Figure 2

Slit lamp examination (A,B) and AS-OCT (C,D) in August 2023. Slit lamp biomicroscopy shows (A) conjunctival hyperemia, severe perikeratic reaction, significant circular, paralimbal, temporal thinning, and crescent-shaped ulceration. Corneal ulcer positive on fluorescein vital coloration (B). AS-OCT images: line across the section of thinning (C). Marked thinning (residual stromal thickness 151 μm), absence of epithelium, pronounced stromal disarray, hyporeflective voids amidst hyper-reflective regions.

Figure 3

Slit lamp examination and corresponding AS-OCT section pointed out by the line across the area of interest. September (A,B): At the 1-month follow-up, with topical and systemic therapy, slit lamp biomicroscopy shows reduced conjunctival hyperemia, decreased temporal thinning, and epithelial integrity with initial conjunctivalization (A). AS-OCT scans reveal a hyporeflective epithelial layer, significant stromal thinning (residual stromal thickness 163 μm), and diffuse stromal hyper-reflectivity absence of hyporeflective voids. October (C,D): Resolution of the inflammatory process. Presence of fibrovascular tissue covering the temporal sector (C). AS-OCT images demonstrate restored stromal thickness (measured 510 μm) with hyper-reflectivity, indicating substantial stromal remodeling (D). December (E,F). Absence of inflammation (E). Enhanced regularity of stromal hyper-reflectivity, suggesting improved alignment of stromal lamellae and overall better tissue organization (F).