Liskova Petra, Hafford-Tear Nathaniel J, Skalicka Pavlina, Malinka Frantisek, Jedlickova Jana, Ďuďáková Ľubica, Pontikos Nikolas, Davidson Alice E, Tuft Stephen
Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic.
Acta Ophthalmol. 2022 Nov;100(7):e1426-e1430. doi: 10.1111/aos.15114. Epub 2022 Feb 17.
Posterior corneal vesicles (PCVs) have clinical features that are similar to posterior polymorphous corneal dystrophy (PPCD). To help determine whether there is a shared genetic basis, we screened 38 individuals with PCVs for changes in the three genes identified as causative for PPCD.
We prospectively recruited patients for this study. We examined all individuals clinically, with their first-degree relatives when available. We used a combination of Sanger and exome sequencing to screen regulatory regions of OVOL2 and GRHL2, and the entire ZEB1 coding sequence.
The median age at examination was 37.5 years (range 4.7-84.0 years), 20 (53%) were male and in 19 (50%) the PCVs were unilateral. Most individuals were discharged to optometric review, but five had follow-up for a median of 12 years (range 5-13 years) with no evidence of progression. In cases with unilateral PCVs, there was statistically significant evidence that the change in the affected eye was associated with a lower endothelial cell density (p = 0.0003), greater central corneal thickness (p = 0.0277) and a steeper mean keratometry (p = 0.0034), but not with a higher keratometric astigmatism or a reduced LogMAR visual acuity. First-degree relatives of 13 individuals were available for examination, and in 3 (23%), PCVs were identified. No possibly pathogenic variants were identified in the PPCD-associated genes screened.
We found no evidence that PCVs share the same genetic background as PPCD. In contrast to PPCD, we confirm that PCVs is a mild, non-progressive condition with no requirement for long-term review. However, subsequent cataract surgery can lead to corneal oedema.
后弹力层角膜小泡（PCV）具有与后极性多形性角膜营养不良（PPCD）相似的临床特征。为了帮助确定是否存在共同的遗传基础，我们对38例PCV患者进行筛查，以寻找已确定为PPCD致病基因的三个基因的变化情况。
我们前瞻性地招募了本研究的患者。我们对所有个体进行了临床检查，如有可能，也对他们的一级亲属进行了检查。我们使用桑格测序法和外显子组测序相结合的方法，对OVOL2和GRHL2的调控区域以及整个ZEB1编码序列进行筛查。
受检者的中位年龄为37.5岁（范围4.7 - 84.0岁），20例（53%）为男性，19例（50%）的PCV为单侧。大多数个体被安排进行验光复查，但有5例进行了中位时间为12年（范围5 - 13年）的随访，没有进展的证据。在单侧PCV的病例中，有统计学意义的证据表明，患眼的变化与较低的内皮细胞密度（p = 0.0003）、更大的中央角膜厚度（p = 0.0277）和更陡峭的平均角膜曲率（p = 0.0034）相关，但与更高的角膜散光或降低的LogMAR视力无关。13例患者的一级亲属可供检查，其中3例（23%）发现有PCV。在所筛查的与PPCD相关的基因中未发现可能的致病变异。
我们没有发现证据表明PCV与PPCD具有相同的遗传背景。与PPCD不同，我们证实PCV是一种轻度、非进行性疾病，无需长期复查。然而，后续的白内障手术可能导致角膜水肿。
