1 | INTRODUCTION
Celiac disease (CD) is a gluten-induced multisystemic autoimmune disease in genetically susceptible individuals.1 In recent years, there has been increasing recognition that the pattern of presentation of pediatric CD may be changing.1,2
Classic CD manifesting with diarrhea, malabsorption and failure to thrive may be less common than the more subtle presentations such as oligosymptomatic, latent, potential, and extraintestinal system findings related with nervous, otologic, dermatological, dental and musculoskeletal findings.3,4 If undiagnosed extraintestinal findings remain untreated, leaving individuals exposed to the risk of long-term complications.5-7
Recent studies eye involvement in systemic and autoinflammatory diseases such as inflammatory bowel disease, diabetes mellitus, rheumatoid arthritis and Behçet’s disease.8-11 Mostly reflected as a change in thicknesses of choroid and ganglion cell complex (GCC). Choroid is highly vascular tissue present between retina and sclera and providing main blood flow to the optical structures effected by circulatory factors, such as intraocular and perfusion pressure, endogenous nitric oxide production and inflammation.12,13
In the acute inflammatory phase, cytokines increase the choroidal vascular permeability and choroidal thickness (CT) usually increases, while atrophic changes in recurrent inflammatory conditions result in decreased CT.8-11,14 CD is also an autoimmune inflammatory disease that would affect eyes of patients. Ocular findings due to CD occupy an important place among these extraintestinal findings because of the direct effect of visual function and ocular comfort on quality of life.5-7 Bölükbaşı et al. has revealed that mean CT measurements at all seven areas of subfoveal, nasal, and temporal points were found to be higher in the adult celiac group.15 There is only one study by Doğan et al. that have found insignificant decrease in thickness of choroid in pediatric CD patients at only subfoveal area. The studies about eye involvement and effect of gluten free diet on ocular findings in CD patients are scarce.1
Optical coherence tomography (OCT) calculates delays in reflected light in different layers of the eye, allowing the reflected light to be converted into 3D images showing depth dimensions. The axial resolution of OCT has currently reached the very low value of 3 microns, and this convenient, non-contact technique can yield images similar to biopsy material viewed under a microscope. OCT can therefore be described as a non-invasive tissue biopsy. Enhanced depth imaging optical coherence tomography (EDI-OCT), a software application that can be installed on spectral domain optical coherence tomography (SD-OCT) devices, is a non-invasive method that provides deeper cross-sectional information about vascularization of choroid, thicknesses of; choroid and GCC which is composed of retinal nerve fibre layer (RNFL), ganglion cell layer (GCL) and ınner plexiform layer (IPL).17,18
Ganglion cell comple is the sum of the three innermost layers: the retinal nerve fiber layer RNFL, which is composed of axons; the GCL, which is composed of cell bodies; and the IPL, which contains the retinal ganglion cells dendrites.12 Early and initial signs of systemic and autoimmune diseases can also be evaluated by measuring the thickness of GCC layers by the help of EDI-OCT.8-11 In Behçet’s disease, systemic lupus erythematosus (SLE), multiple sclerosis (MS) and obesity patients thicknesses of GCC layers are decreased due to effects of autoinflammatory diseases and metabolic stress.11,14,19,20 There is only one study in adult and one small size pediatric study reporting thinning of RNFL layer in CD patients.21,22 In the present study, measurement of thicknesses of choroid (at subfoveal, nasal and temporal points) and GCC (RNFL at seven points GCL and IPL) in pediatric CD and control group in order to evaluate eye findings and effect of gluten free diet on ocular involvement which is an important extraintestinal finding of CD.