Abstract
Purpose: :
To determine whether anterior segment optical coherence tomography (ASOCT) can be used to categorize scleral inflammation into necrotizing and non-necrotizing disease, as well as to help objectively follow the extent of inflammation during the course of disease under treatment.
Methods: :
Two patients with normal sclera and four patients with active scleritis were imaged with ASOCT between November and December of 2010. Data on race, age, medical history, treatment, and slit lamp findings was obtained. Normal sclera served as controls to help delineate the various anatomical layers. Patients with active disease were re-imaged during follow up clinic visits. These were subsequently analyzed for objective changes in scleral thickness, distribution of involvement, as well as the presence or absence of necrosis.
Results: :
Analysis of images taken of normal sclera revealed a distinct layer of homogenous, hyporeflective conjunctiva and episclera overlying a homogenous layer of hyperreflective sclera. Extraocular muscles and their insertion point on the sclera could also be seen clearly. Of the four patients with scleral disease, two patients had necrotizing scleritis from TB and two had non-necrotizing nodular scleritis. Imaging confirmed slit lamp findings in all patients. The two patients with tuberculous scleritis demonstrated necrotic scleral nodules appearing as areas of focal thinning with underlying heterogeneous hyporeflectivity adjacent to edematous, hyporeflective sclera. The two patients with nodular scleritis demonstrated a well demarcated region of scleral thickening adjacent to normal sclera, with evidence of both heterogenerous hyporeflectivity within the lamellae as well as fluid pooling. The two tuberculous scleritis patients demonstrated modest decrease in scleral thickening 1 week after initiation of treatment based on imaging.
Conclusions: :
To date, scleral inflammatory disease continues to be treated based primarily on findings during slit lamp examination. In situations where there is minimal evidence of either progression or remission of disease, scleral imaging can be useful. There are two published reports on the utility of ultrasound biomicrosopy (UBM) in the highlighting scleral inflammation and necrosis. The disadvantages of UBM, including the relatively low resolution and difficulty in obtaining images, are solved with OCT. This study is the first report in the literature of OCT use in the evaluation of scleritis. The images reviewed reveal a potential new use in following patients with active scleral inflammation, as well as post-inflammatory sequelae.
Keywords: sclera • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • inflammation