Prenatal Ultrasound Diagnosis of Persistent Hyperplastic Primary Vitreous with Retinoblastoma

INTRODUCTION

Persistent hyperplastic primary vitreous (PHPV) involves a spectrum of congenital ocular abnormalities characterized by the presence of a vascular membrane behind the lens. Retinoblastoma is a life-threatening intraocular malignancy that can cause blindness, eye loss, or even death. PHPV and retinoblastoma are extremely rare prenatal diseases.

CASE PRESENTATION

Here, we present a case of fetal PHPV with retinoblastoma diagnosed using prenatal ultrasound. The unilateral lenses were hyperechoic, and irregular echogenic bands between the lenses and posterior eye walls were observed. In cases where the blood flow signal continues in the band-shaped hyperechoic area, PHPV with retinoblastoma should be suspected.

CONCLUSION

PHPV with retinoblastoma can be prenatally diagnosed.

Modulating EGFR-MTORC1-autophagy as a potential therapy for persistent fetal vasculature (PFV) disease

Persistent fetal vasculature (PFV) is a human disease that results from failure of the fetal vasculature to regress normally. The regulatory mechanisms responsible for fetal vascular regression remain obscure, as does the underlying cause of regression failure. However, there are a few animal models that mimic the clinical manifestations of human PFV, which can be used to study different aspects of the disease. One such model is the Nuc1 rat model that arose from a spontaneous mutation in the Cryba1 (crystallin, beta 1) gene and exhibits complete failure of the hyaloid vasculature to regress. Our studies with the Nuc1 rat indicate that macroautophagy/autophagy, a process in eukaryotic cells for degrading dysfunctional components to ensure cellular homeostasis, is severely impaired in Nuc1 ocular astrocytes. Further, we show that CRYBA1 interacts with EGFR (epidermal growth factor receptor) and that loss of this interaction in Nuc1 astrocytes increases EGFR levels. Moreover, our data also show a reduction in EGFR degradation in Nuc1 astrocytes compared to control cells that leads to over-activation of the mechanistic target of rapamycin kinase complex 1 (MTORC1) pathway. The impaired EGFR-MTORC1-autophagy signaling in Nuc1 astrocytes triggers abnormal proliferation and migration. The abnormally migrating astrocytes ensheath the hyaloid artery, contributing to the pathogenesis of PFV in Nuc1, by adversely affecting the vascular remodeling processes essential to regression of the fetal vasculature. Herein, we demonstrate in vivo that gefitinib (EGFR inhibitor) can rescue the PFV phenotype in Nuc1 and may serve as a novel therapy for PFV disease by modulating the EGFR-MTORC1-autophagy pathway.

ABBREVIATIONS

ACTB: actin, beta; CCND3: cyclin 3; CDK6: cyclin-dependent kinase 6; CHQ: chloroquine; COL4A1: collagen, type IV, alpha 1; CRYBA1: crystallin, beta A1; DAPI: 4'6-diamino-2-phenylindole; EGFR: epidermal growth factor receptor; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GFAP: glial fibrillary growth factor; KDR: kinase insert domain protein receptor; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MKI67: antigen identified by monoclonal antibody Ki 67; MTORC1: mechanistic target of rapamycin kinase complex 1; PARP: poly (ADP-ribose) polymerase family; PCNA: proliferating cell nuclear antigen; PFV: persistent fetal vasculature; PHPV: persistent hyperplastic primary vitreous; RPE: retinal pigmented epithelium; RPS6: ribosomal protein S6; RPS6KB1: ribosomal protein S6 kinase, polypeptide 1; SQSTM1/p62: sequestome 1; TUBB: tubulin, beta; VCL: vinculin; VEGFA: vascular endothelial growth factor A; WT: wild type.

Persistent Fetal Vasculature

During development, the fetal vasculature nourishes the developing lens and retina, and it subsequently regresses after the formation of the retinal vessels. Persistent fetal vasculature (PFV) occurs as a result of a failure of fetal ocular vasculature to undergo normal programmed involution, which leads to blindness or serious loss of vision. Persistent fetal vasculature is responsible for as much as 5% of childhood blindness in western countries. The regulatory mechanisms responsible for fetal vascular regress remain obscure, as do the underlying causes of the failure of regression. Because of recent advancements in microinvasive surgical techniques, the early treatment of PFV has become safer and more effective, thus paving the way for the development of a future new treatment strategy. In this review, clinical and imaging manifestations of PFV and the progress in the treatment of PFV are highlighted.

[Complex ultrasound examination children with persisting hyperplastic primary vitreous]

Complex ultrasound examination was performed in 108 children with unilateral congenital cataract (UCC) and persisting hyperplastic primary vitreous syndrome (PHPVS) to reveal indications and contraindications for surgery. The presence of functioning vessels with linear blood flow velocity (LBFV) measurement was performed in fibrovascular band and retrolenticular membrane (RLM) in different stages of PHPVS using color Doppler and energetic mapping. The echographic density of fibrovascular band and RLM was estimated using echodensitometry. The results of the study showed correlation of PHPVS severity and fibrovascular band diameter, LBFV in the vessels of the band and echographic density of the band, RLM and their thickness as well.

[Persistent fetal vasculature syndrome--clinical image and diagnostic difficulties]

PURPOSE

The aim of this review is to present cases of clinically differentiated picture of persistent fetal vasculature syndrome--PFVS (also called persistent hyperplastic primary vitreous body--PHPVB) observed in group of infants and children.

MATERIAL AND METHODS

Case records of four children with characteristic changes of posterior form of persistent fetal vasculature syndrome, which were observed on fundus of the eyes, were analyzed retrospectively. Routine ophthalmological examination, genetic, cytogenetic and laboratory tests towards coexisting bacterial, viral and parasitic diseases and congenital anomaly of the eye or chorioretinal neoplastic changes of neonatal period were performed. Ophthalmological changes were archived using Ret-Cam II apparatus (Clarity Medical Systems). Measurement of the axial diameter of the eyes and exclusion coexisting ocular disease by ultrasonography (A-scan US i B-scan US and color Doppler ultrasonography--CDU), were performed.

RESULTS

Different clinical image of posterior form of persistent hyperplastic primary vitreous body was observe in ophthalmological examination. Changes such as fibrovascular tissue connecting optic disc (n. II) with ora serrata of the retina coexisting with retinoschisis, retrolental mass or persistent hyaloid artery were observed. Additionally concomitant features in pathological eyes were: iris hypoplasia, corectopia, microphthalmia, congenital cataract, secondary glaucoma, degeneration or retinoschisis and intrvitreous haemorrhage. Strabismus, nystagmus and heart disease in the form of persistent fetal circulation were associated with ophthalmological changes. Inflammatory and genetically determined diseases were excluded in differential diagnosis.

CONCLUSIONS

The diagnosis of persistent hyperplastic primary vitreous body (PHPVB) was confirmed by characteristic clinical symptoms and results of the additional research. Suggestion of recognition of this syndrome (PHPVB) as well as persistent fetal vasculature syndrome (PFVS) should be implemented diagnostics towards other optic and systemic development defects.

[Histopathological study of retrolental membranes secondary to persistent hyperplastic primary vitreous]

OBJECTIVE

To study the pathological characteristics of retrolental membranes (RLMs) secondary to persistent hyperplastic primary vitreous (PHPV), and to discuss the possible pathogenesis of PHPV.

METHODS

Experimental study. Six RLMs obtained from six patients with PHPV during vitrectomy were examined by light microscopy (HE & PAS staining). All of them were observed with proliferating cell nuclear antigen (PCNA) immunostaining, together with collagen I, factor VIII related antigen, smooth muscle actin (SMA), epithelial membrane antigen (EMA), neuron specific enolase (NSE) and glial fibrillary acidic protein (GFAP) staining. Apoptosis were detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL).

RESULTS

Light microscopy showed that the RLM was a dense connective tissue with numerous inflammatory cells including mast cells and lymphocytes. PAS staining showed that RLMs contained a larger amount of polysaccharides. Histopathology and immunohistochemistry showed that there were vascular channels, smooth muscle cells, nervous cells and epithelial cells scattered in RLMs. Collagen I was the main component of RLMs. PCNA-positive nuclei were widely found in RLMs. TUNEL-positive nuclei were also found in all RLMs, as well as in the posterior subcapsular epithelial cells of lens.

CONCLUSIONS

The cell types of RLMs secondary to PHPV are similar to those of the primary vitreous. It is possible that the mechanism of the progression of RLMs is the over-development and incomplete regression of the retrolental vascular system. Inflammation may play an important role in the regression of RLMs.

Prenatal ultrasonographic diagnosis of persistent hyperplastic primary vitreous

Persistent hyperplastic primary vitreous (PHPV) is a rare developmental malformation of the eye characterized by the presence of a vascular membrane located behind the lens. We report, for the first time in the literature, the identification on ultrasound examination of bilateral cataract and thickened hyaloid artery-lens junction, leading to a diagnosis of bilateral PHPV, in a fetus at 23 weeks' gestation. Histological examination at postmortem confirmed the prenatal diagnosis of bilateral PHPV and cataract. A thorough ultrasound examination of the fetal eye in cases with cataract is recommended.