Abstract
Purpose: :
To demonstrate the in vivo morphological characteristics of vernal keratoconjunctivitis (VKC) by the application of in vivo laser scanning confocal microscope.
Methods: :
26 patients (26 eyes) diagnosed as VKC were enrolled in the study. The Heidelberg retina tomograph (HRTII)/Rostock cornea module (RCM) was applied to examine bulbar conjunctiva, tarsal conjunctiva, superior limbus and inferior limbus. The density of Langerhans cells and inflammatory cells in tarsal conjunctiva and bulbar conjunctiva were calculated by the software. The morphology of Vogt Palisades was analyzed and normal rate of Vogt Palisades at superior and inferior limbus was calculated respectively.
Results: :
Infiltration of numerous Langerhans cells and inflammatory cells could be identified in both bulbar conjunctiva and tarsal conjunctiva, along with giant papillary formation in tarsal conjunctiva. The density of Langerhans cells and inflammatory cells in VKC patients were significantly higher than normal subjects. Furthermore, the density of inflammatory cells and Langerhans cells in tarsal conjunctiva were significantly higher in tarsal form and mix form than bulbar form (P=0.048 and 0.053, respectively). Normal Vogt Palisades were visible only in 15 eyes (57.7%) at superior limbus and 23 eyes (88.5%) at inferior limbus in VKC patients. In those with abnormal limbal morphology, Vogt Palisades were atrophic or totally damaged which characterized with atrophy or absence of stromal papillae and disappearance of bright basal cells, accompanied with infiltration of numerous Langerhans cells and dilated vessels. At superior limbal area, bulbar form had the highest abnormal rate, followed by mix form, both of which were significantly higher than tarsal form (P=0.005).
Conclusions: :
The in vivo morphological characteristics of conjunctiva and limbus in VKC patients included the infiltration of Langerhans cells and inflammatory cells in epithelium and stroma, and the destruction of Vogt Palisades as well. In vivo LSCM was helpful in discriminate the subtypes of VKC.
Keywords: conjunctivitis • imaging/image analysis: clinical • microscopy: confocal/tunneling