Noninvasive Observations of Peripheral Angle in Eyes After Penetrating Keratoplasty Using Anterior Segment Fourier-Domain Optical Coherence Tomography

Purpose: To examine iridotrabecular contact (ITC) as a peripheral anterior synechia (PAS) of patients who underwent penetrating keratoplasty (PKP) using anterior segment Fourier-domain optical coherence tomography (OCT). Methods: Retrospective, observational case series. ITC, ITC index, and ITC area of 60 eyes of 52 patients who underwent PKP at the Department of Ophthalmology in the University of Tokyo Hospital (mean follow-up time 102.8 +/- 116.1 months postoperation) were calculated using the angle analysis mode of a commercially available anterior segment Fourier-domain OCT system (CASIA; TOMEY, Nagoya, Japan). We analyzed the occurrence of ITC, ITC index, and ITC area with preoperative diagnosis, lens status, operation method, operation frequency, graft size, and intraocular pressure elevation. Results: ITC was observed in 28 (46.7%) of 60 eyes. Average ITC index was 14.0%, and average ITC area was 5.97 mm(2). ITC was significantly associated with eyes with bullous keratopathy, infectious keratitis, pseudophakia, PKP with cataract operation, several PKP operations, and large graft size. Conclusions: Anterior segment Fourier-domain OCT is a useful and innovative tool that enables us to observe the anterior chamber angle and examine ITC as PAS of eyes with corneal opacity, even after PKP.