Three-dimensional assessment of posterior polymorphous corneal dystrophy with swept-source optical coherence...

Posterior polymorphous corneal dystrophy (PPCD), also known as Schlichting dystrophy, can present as either autosomal dominant or isolated unilateral cases, with a similar phenotype but without a hereditary pattern. This study aimed to investigate the characteristics of PPCD using wide-field, high-resolution, swept-source optical coherence tomography (SS-OCT).

We retrospectively reviewed 16 eyes of 10 patients with PPCD, all of whom exhibited typical slit-lamp biomicroscopic and in vivo confocal microscopy (IVCM) findings, including endothelial vesicular, placoid, and/or band-like pathological changes. All participants underwent a comprehensive ophthalmological assessment, including anterior segment imaging, corneal endothelial specular microscopy, and IVCM. Wide-field SS-OCT was performed on the cornea, and the cornea's posterior surface was then individually visualized and analyzed.

In total, 16 eyes of 10 patients (six females and four males), aged 9 to 30 years, were included in this study. The wide-field en-face SS-OCT system revealed hyper-reflective, round lesions in 7 eyes, and band-like hyper-reflective lesions in 9 eyes at the level of the inner corneal surface. The mean endothelial cell density (ECD) was 2,024.1±369.4 cells/mm² (range, 1,706-2,768 cells/mm²). The mean proportion of the corneal lesion area in the total corneal area was 3.57%±1.82% (range, 0.07-6.31%). No statistically significant difference was observed in the corneal affected area of different types of PPCD (P>0.05). Lower ECD (r=-0.8044, P<0.001) and hexagonality (r=-0.5419, P<0.05) were observed in patients with involvement of the central visual axis of the cornea.

Non-invasive wide-field SS-OCT can clearly identify characteristic microstructural alterations at the level of the whole posterior corneal surface in PPCD, and may aid in the diagnosis and follow-up of PPCD.