Person:

Nakao, Takeshi

Background: Conjunctival pyogenic granulomas are commonly seen after ocular surgeries or at an ocular wound site. The aim of this study is to describe a novel histological classification for medically uncontrolled conjunctival pyogenic granulomas (MUCPG), and to explore whether the diversity in clinical features correlates to different histological subtypes of MUCPG. Methods: This is an observational cross-section case series. We reviewed 46 consecutive patients with conjunctival pyogenic granulomas who did not respond to topical corticosteroids and underwent surgical excision from January 1, 2006 through December 31, 2015. Clinical features and histological findings were presented and analyzed. Results: Ocular surgery, accidental injury, and chalazion were the main predisposing causes of MUCPG. The lesions tended to occur unilaterally on the bulbar conjunctiva. Forty patients (87%) presented an enrichment of inflammatory cells and proliferated capillaries in their pathological sections (inflammatory pattern). Six patients (13%) showed relatively few inflammatory cells and capillaries within fibrous stroma (fibrous pattern). Patients with the inflammatory pattern were older (p = 0.025) and tended to be located in bulbar conjunctiva (p = 0.002). The predisposing causes were also different between two histological subtypes (p = 0.007). Conclusions: We found the correlation between clinical presentation and histological subtypes in patients with MUCPG, indicating this disease may need a new classification scheme.

Corneal thickness is tightly regulated by its boundary endothelial and epithelial layers. The regulated set-point of corneal thickness likely shows inter-individual variations, changes by age, and response to stress. Using anterior segment-optical coherence tomography, we measure murine central corneal thickness and report on body size scaling of murine central corneal thickness during aging. For aged-matched mice, we find that corneal thickness depends on sex and strain. To shed mechanistic insights into these anatomical changes, we measure epithelial layer integrity and endothelial cell density during the life span of the mice using corneal fluorescein staining and in vivo confocal microscopy, respectively and compare their trends with that of the corneal thickness. Cornea thickness increases initially (1 month: 114.7 ± 3.0 μm, 6 months: 126.3 ± 1.6 μm), reaches a maximum (9 months: 129.3 ± 4.4 μm) and then reduces (12 months: 127 ± 2.9 μm, 13 months: 119.5 ± 7.6 μm, 14 months: 110.6 ± 10.6 μm), while the body size (weight) increases with age. We find that endothelial cell density reduces from 2 months old to 8 months old as the mice age and epithelial layer accumulates damages within this time frame. Finally, we compare murine corneal thickness with those of several other mammals including humans and show that corneal thickness has an allometric scaling with body size. Our results have relevance for organ size regulation, translational pharmacology, and veterinary medicine.