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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.