ABSTRACT
Background Eyes with filamentary keratitis present with serious clinical symptoms.This disease is easy to relapse and the treatment is tricky.At present,its pathogenesis is still unclear,and few works were done on filamentous composition.Objective This study was to analyze the composition of corneal filament by imageological and histopathological method,and discuss the formation mechanism of filamentary keratitis.Methods Eighty-eight eyes of 82 cases who suffered from filamentary keratitis were collected in Shandong Eye Hospital between January 2008 and January 2011.The etiologies of the patients were classified and the clinical data were recorded.Firstly,the corneal filiform strip was detected by laser scanning confocal microscopy (LSCM),and the corneal structure was examined by high-definition optical coherence tomography (HD-OCT).Then the composition of filamentary strip was analyzed by Giemsa and Masson trichrome staining of stretched preparation of filiform strip.Results Etiological study showed that filamentary keratitis occurred after penetrating keratoplasty in 40 eyes,after cataract surgery and photorefractive keratectomy (PRK) in 18 eyes,dry eye and neural dystrophic corneal disease in 14 eyes,acute conjunctivitis in 10 eyes.HD-OCT revealed that filament lesion developed to Bowman layer.Filament was composed of epithelial cells,inflammatory cells,mucus and the high reflective strip core with spiral arrangement under the LSCM,and epithelial cells,inflammatory cells and fibrous tissue were seen in the strip core.Giemsa staining exhibited that filament contained corneal epithelial cells,inflammatory cells,mucus and dark blued strip core with helical arrangement.Masson trichrome discovered that the strip core was red fibrous tissue surrounding by blue mucus.Conclusions Epithelial cells,inflammatory cells,mucus and the high reflective strip core with spiral arrangement are the main elements of filament in filamentary keratitis.The lesion can reach Bowman layer.The results contribute to reveal the formation mechanism of corneal filament and assist treatment.