AIM: To explore the imaging features of 49 patients with posterior polymorphous corneal dystrophy(PPCD)by in vivo confocal microscopy(IVCM).

METHODS: Retrospective case series study. A total of 49 patients(86 eyes), including 32 males and 17 females diagnosed with PPCD between January 2013 and January 2021 were collected. The mean age was 42.5±22.9 years. All patients were scanned by IVCM to analyze the density of corneal endothelial cells and described IVCM characteristics of different types of PPCD.

RESULTS: The number of endothelial cells in the lesion area of all patients was lower than that in the peripheral area. Under IVCM, 44 eyes(51%)were categorized into type 1 PPCD(vesicular lesions), characterized by single or multiple, central round or irregular crater-like lesion on paracentral corneal endothelial layer; 16 eyes(19%)were categorized into type 2 PPCD(band lesions), which displayed curved and raised edge with scattered or banded-distributed gutta-like lesion between edges. Type 3 PPCD(diffuse lesion)were in 26 eyes(30%), which showed that endothelial cells were missing in many areas. The blurred images of endothelium in most areas featured with spikes lined in a streak, and the clear images in some areas featured with a band lesions. Two patients were followed up for 4-5a. The IVCM images showed different lesions, including the decrease of central corneal endothelial cell density and the iron deposit in the corneal epithelium, etc.

CONCLUSION: IVCM is able to scan the characteristic microstructural alterations at the level of endothelium and Descemet membrane in patients with PPCD, and provide an effective image diagnosis for PPCD.