Abstract: Objective To identify the clinical manifestations and in vivo confocal microscopy (IVCM) imaging changes of the patients with Thiel-Behnke corneal dystrophy (TBCD). Design Prospective study. Participants A TBCD patient and her family. Methods Ocular surface examinations were performed on the members of the TBCD family, which included vision acuity, slit-lamp microscope, IVCM, and anterior segment optical coherence tomography (AS-OCT). Meanwhile, 10 ml of peripheral venous blood was taken from this pedigree to prepare for leukocyte genomic DNA. The TGFBI gene was amplified by PCR, and the patient's gene sequence were analyzed. Main outcome Measures Results of vision acuity in TBCD patients, characteristics of cornea lesion with slit lamp, IVCM, AS-OCT examinations, and the condition of patient's gene sequence mutation. Results Among 35 members in this four-generation family, diffuse, grayish-white turbid deposits were detected at the Bowman layer in 10 TBCD patients. The lesions were mainly located at the Bowman layer in the central and mid-peripheral cornea area. Point-like opacity, with linear or honeycomb shape, could also be explored in the superficial stroma. With AS-OCT examination, continuous, uniform and highly reflective deposits were detected in the Bowman layer and superficial stroma layer of the cornea. The anterior part of the deposit (toward the epithelial layer) presented sawtooth-like lesion. From the epithelial layer to superficial layer, high-reflective, irregular, and amorphous deposits were detected with IVCM examination. No inflammatory cell infiltration was found in the lesion area and surrounding tissues. Molecular genetic analysis revealed a single heterozygous G>A mutation at the second base of codon 39 in exon 12 of the TGFBI gene of the pedigree affected with TBCD, but not in the unaffected members. It could result in the conversion of arginine to glutamine (R555Q). Conclusion With IVCM examinations, TBCD with R555Q mutation was manifested as highly reflective, irregular, and amorphous substance deposition in the Bowman layer of the cornea.

Key words: Thiel-Behnke corneal dystrophy, in vivo confocal microscopy, gene mutation, R555Q