Iridocorneal Endothelial Syndrome with Features of Posterior Polymorphous Corneal Dystrophy

Purpose: To report a case of iridocorneal endothelial syndrome, which overlapped with some of the features of posterior polymorphous corneal dystrophy. Case summary: A 61-year-old female presented with tearing pain and blurred vision in her left eye, which was aggravated in the morning. The symptom started approximately 1 year prior to her visit. At the initial visit, the visual acuities were 1.0 in both eyes and the intraocular pressures were normal. On slit-lamp examination, a single pair of horizontal parallel lines was observed at the central corneal endothelial layer in the right eye. In contrast, multiple pairs of oblique parallel lines were observed in the left eye. The lines of the lesions were more prominent and wavier in the left eye than those of the right eye. The overlying cornea was clear, and the corneal thicknesses were in the normal range in both eyes. Using a gonioscopic examination, localized peripheral anterior synechiae were observed only in the left eye. The pupil and iris were normal in both eyes. On specular microscopic examination, the corneal endothelial cell size in the right eye increased and the corneal endothelial density decreased to 668 cells/mm(2). In the left eye, multiple abnormal endothelial cells with dark-light reversal were observed. In conclusion, the patient was subsequently diagnosed with iridocorneal syndrome, rather than posterior polymorphous corneal dystrophy. Conclusions: Posterior polymorphous corneal dystrophy and iridocorneal endothelial syndrome may present with many similarities. Therefore, in cases of uncertain diagnosis, an understanding of the clinical features is important for proper diagnosis.