Assessment of conjunctival, episcleral and scleral thickness in healthy individuals using anterior segment optical coherence tomography

PURPOSE

To determine the thickness of the conjunctiva, episclera and sclera in healthy individuals using anterior segment optical coherence tomography (AS-OCT).

METHODS

We prospectively included 107 healthy individuals of different age groups (18-39 years, 40-54 years, 55-69 years and ≥70 years). For each eye, AS-OCT scans of four quadrants (temporal, nasal, superior and inferior) were acquired. The thickness of the conjunctiva, episclera and sclera was measured for each scan. In addition, the axial length of both eyes was measured, and general characteristics, including smoking, allergies and contact lens use, were collected.

RESULTS

The mean conjunctival thickness was significantly different between the nasal and superior quadrants (87 ± 30 μm vs. 77 ± 16 μm; p < 0.001), as well as the superior and inferior quadrants (77 ± 16 μm vs. 86 ± 19 μm; p = 0.001). The mean episcleral thickness was larger in the superior (174 ± 54 μm) and inferior (141 ± 43 μm) quadrants, compared to the nasal (83 ± 38 μm) and temporal quadrants (90 ± 44 μm). The mean scleral thickness of the inferior quadrant was the largest (596 ± 64 μm), followed by the nasal (567 ± 76 μm), temporal (516 ± 67 μm) and superior (467 ± 52 μm) quadrants (all p < 0.001). The averaged scleral thickness increased 0.96 μm per age year (0.41-1.47 μm, p < 0.001).

CONCLUSIONS

This study provides an assessment of the thickness of scleral and adjacent superficial layers in healthy individuals determined on AS-OCT, which could enable future research into the use of AS-OCT in diseases affecting the anterior eye wall.

Clinical Relevance of Autoantibodies and Inflammatory Parameters in Non-infectious Scleritis

PURPOSE

Scleritis is a potentially blinding disorder, with highly unpredictable course and outcome. We analyzed the prevalence and clinical relevance of autoantibodies and inflammatory parameters in non-infectious scleritis.

METHODS

Retrospective analysis of laboratory findings in all consecutive patients at the department of Ophthalmology of the Erasmus MC with non-infectious scleritis.

RESULTS

We included 81 patients with non-infectious scleritis. A systemic autoimmune disease was present in 46%. Positive anti-nuclear antibodies were found in 30%, anti-neutrophil cytoplasmic antibodies were positive in 19%, and the presence of rheumatoid factor was shown in 17%. The aforementioned autoantibodies, as well as inflammatory parameters, failed to show prognostic clinical value. In contrast, anti-citrullinated peptide antibodies (ACPA), found in 9% of scleritis patients, were significantly associated with the development of scleral necrosis (P = .01).

CONCLUSIONS

The presence of ACPA in patients with non-infectious scleritis was associated with the development of scleral necrosis.

Subconjunctival Rituximab Administration for the Treatment of Scleritis

PURPOSE

Scleritis is a sight-threatening inflammation, which is commonly accompanied by severe complications. Aggressive systemic immunosuppressive treatment, which is frequently needed, can be associated with serious complications, and might therefore be (temporarily) contraindicated.

METHODS

We report on the outcomes of three patients with severe, active, non-infectious scleritis, refractory or intolerant to systemic treatment, who received subconjunctival rituximab (RTX) injections. A dose of 2.5 to 7.5 mg was administered after topical anesthesia, and follow-up varied from 8 to 10 months.

RESULTS

Subconjunctival RTX showed minimal to no effect on subjective symptoms, clinical features and/or ultrasound images. No serious adverse effects occurred.

CONCLUSION

Further studies are needed to assess the effect of local administration of RTX in scleritis, but our limited observation is not promising.

Current insights in the pathogenesis of scleritis

Scleritis is a sight-threatening inflammation characterized by severe pain and redness of the eye. It can cause blindness by severe complications like scleral and corneal necrosis, keratitis, and uveitis. The pathogenesis of scleritis is largely unknown due to a combination of the rarity of the disease, the little available human tissue-based research material, and the lack of animal models. The immune system is assumed to play a crucial role in the pathogenesis of scleritis. Multiple clues indicate probable antigenic stimuli in scleritis, and the involvement of matrix metalloproteinases in the destruction of scleral tissue. In this article we review the current insights into the pathogenesis of scleritis, and we suggest new hypotheses by implementing knowledge of systemic autoimmune disease pathogenesis. Understanding the pathogenesis of scleritis is crucial to improve the clinical management, as well as to find novel treatment modalities.