Familial exudative vitreoretinopathy mimicking persistent hyperplastic primary vitreous

Persistent vasa hyaloidea propria/retinae in familial exudative vitreoretinopathy

The vasa hyaloidea propria, a component of the fetal hyaloidal vasculature, is characterized by multiple persistent fetal vasculatures branching into the vitreous. We present a 4-month-old girl with stage 4 familial exudative vitreoretinopathy, with multiple ectopic retinal vessels extending into the vitreous, confirmed with fluorescein angiography, which was consistent with persistent vasa hyaloidea propia/retinae making contact with the retina. The patient underwent vitreoretinal surgery to address the retinal detachment, during which the patent stalks of the persistent vasa hyaloidea propia/retinae were transected.

Early Diagnosis and Management of Aggressive Posterior Vitreoretinopathy Presenting in Premature Neonates

BACKGROUND AND OBJECTIVE

Aggressive posterior vitreoretinopathy (APVR) manifests with a broad area of retinal avascularity, progressive neovascularization, and/or tractional retinal detachment during the neonatal period.

PATIENTS AND METHODS

A multicenter, retrospective, observational, consecutive case series study was performed to evaluate the retinal findings and structural retinal outcomes in patients treated for APVR within the first 3 months of life.

RESULTS

Three premature neonates with a non-retinopathy of prematurity (ROP) APVR identified during routine ROP screening exams exhibited relatively severe, rapidly progressive retinal vascular abnormalities. Immediate laser photocoagulation of the avascular retina and vitrectomy for traction retinal detachment within several days to weeks improved or stabilized the retinal anatomy in all cases.

CONCLUSIONS

This series describes clinical features in APVR in premature infants and suggests that early diagnosis and intervention may mitigate the typical aggressive course and poor prognosis of this condition. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:201-207.].

25-gauge lens-sparing vitrectomy with dissection of retrolental adhesions on the peripheral retina for familial exudative vitreoretinopathy in infants

BACKGROUND

To evaluate the clinical outcome of 25-gauge lens-sparing vitrectomy with dissection of retrolental adhesions on the peripheral retina for familial exudative vitreoretinopathy in infants.

METHODS

Fifty-one eyes of 39 infants with familial exudative vitreoretinopathy associated with retrolental adhesions on the peripheral retina, retinal fold with macular detachment, and partial lens opacity. A 25-gauge lens-sparing vitrectomy was performed, and retrolental adhesions between the peripheral retina and the posterior lens capsule were surgically dissected. Lens opacification, as assessed or graded by Lens Opacities Classification System III, and the retinal reattachment rate were observed and recorded monthly for up to 7 months postoperatively.

RESULTS

After 7 months, the detached retina along the retinal fold was reattached in 42/51 (82.4%) eyes; the macula was reattached completely in 26/51 (51.0%) eyes and partially in 15/51 (29.4%) eyes. There was no statistically significant change in the lens opacity of the posterior capsule or cortex before or after surgery (P > 0.05, paired t test) or in postoperative progression of lens opacity (P > 0.05, modified McNemar's test) according to Lens Opacities Classification System III scores.

CONCLUSIONS

A 25-gauge lens-sparing vitrectomy with dissection of peripheral retinal retrolental adhesions is helpful for preservation of the lens and reattachment of the macula in infants with FEVR.

Fzd4 Haploinsufficiency Delays Retinal Revascularization in the Mouse Model of Oxygen Induced Retinopathy

Mutations in genes that code for components of the Norrin-FZD4 ligand-receptor complex cause the inherited childhood blinding disorder familial exudative vitreoretinopathy (FEVR). Statistical evidence from studies of patients at risk for the acquired disease retinopathy of prematurity (ROP) suggest that rare polymorphisms in these same genes increase the risk of developing severe ROP, implying that decreased Norrin-FZD4 activity predisposes patients to more severe ROP. To test this hypothesis, we measured the development and recovery of retinopathy in wild type and Fzd4 heterozygous mice in the absence or presence of ocular ischemic retinopathy (OIR) treatment. Avascular and total retinal vascular areas and patterning were determined, and vessel number and caliber were quantified. In room air, there was a small delay in retinal vascularization in Fzd4 heterozygous mice that resolved as mice reached maturity suggestive of a slight defect in retinal vascular development. Subsequent to OIR treatment there was no difference between wild type and Fzd4 heterozygous mice in the vaso-obliterated area following exposure to high oxygen. Importantly, after return of Fzd4 heterozygous mice to room air subsequent to OIR treatment, there was a substantial delay in retinal revascularization of the avascular area surrounding the optic nerve, as well as delayed vascularization toward the periphery of the retina. Our study demonstrates that a small decrease in Norrin-Fzd4 dependent retinal vascular development lengthens the period during which complications from OIR could occur.

Familial exudative vitreoretinopathy and related retinopathies

Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder of retinal angiogenesis. Cases can be autosomal dominant, autosomal recessive, or X-linked. FEVR patients have an avascular peripheral retina which, depending on the degree of ischaemia, causes the secondary complications of the disease. Expressivity may be asymmetric and is highly variable. Five genes have been identified that when mutated, cause FEVR; NDP (X-linked), FZD4 (autosomal dominant and recessive), LRP5 (autosomal dominant and recessive), TSPAN12 (autosomal dominant and recessive), and ZNF408 (autosomal dominant). Four of these genes have been shown to have a central role in Norrin/Frizzled4 signalling, suggesting a critical role for this pathway in retinal angiogenesis. In addition to the ocular features, LRP5 mutations can cause osteopenia and osteoporosis. All FEVR patients in whom molecular testing is not easily accessible should have dual energy X-ray absorptiometry (DEXA) scans to assess bone mineral density, as treatment can be initiated to reduce the risk of bone fractures.

Reduced bone mineral density and hyaloid vasculature remnants in a consanguineous recessive FEVR family with a mutation in LRP5

BACKGROUND/AIMS

Familial exudative vitreoretinopathy (FEVR) is an inherited blinding condition characterised by abnormal development of the retinal vasculature. FEVR has multiple modes of inheritance, and homozygous mutations in LRP5 have recently been reported as underlying the recessive form of this disease. The aim of this study was to examine LRP5 in a consanguineous recessive FEVR family and to clarify the eye and bone phenotype associated with recessive FEVR.

METHODS

All family members were examined by slit lamp biomicroscopy and indirect ophthalmoscopy. Linkage to LRP5 was determined by genotyping microsatellite markers, constructing haplotypes and calculating lod scores. Mutation screening of LRP5 was performed by polymerase chain reaction amplification of genomic DNA followed by direct sequencing. Bone mineral density (BMD) was evaluated in all family members using dual energy x ray absorptiometry (DEXA).

RESULTS

The clinical features observed in this family were consistent with a diagnosis of recessive FEVR. A homozygous LRP5 missense mutation, G550R, was identified in all affected individuals and all unaffected family members screened were heterozygous carriers of this mutation. Reduced BMD, hyaloid vasculature remnants, and nystagmus were features of the phenotype.

CONCLUSION

Recessive mutations in LRP5 can cause FEVR with reduced BMD and hyaloid vasculature remnants. Assessment of a patient with a provisional diagnosis of FEVR should therefore include investigation of BMD, with reduced levels suggestive of an underlying LRP5 mutation.

Persistence of fetal vasculature in a patient with Knobloch syndrome: potential role for endostatin in fetal vascular remodeling of the eye

OBJECTIVE

To report a child with Knobloch syndrome (KS) with features of persistent fetal vasculature (PFV) and to discuss the possible role of endostatin in vascular remodeling of the fetal eye.

DESIGN

Case report with enzyme-linked immunosorbent assay (ELISA) analysis of serum endostatin.

MAIN OUTCOME MEASURES

Ocular examination, fluorescein angiography, echography, ELISA analysis of serum endostatin, and typing for pathogenic mutations in COL18A1.

RESULTS

Slit-lamp examination in the left eye disclosed numerous findings of PFV, including an extensive persistent pupillary membrane, scarcity of iris crypts, and pigmented epicapsular stellate remnants on the anterior lens surface. Dilated fundus examination revealed a total posterior vitreous detachment, despite the young age of the patient, with numerous white intragel opacities that were compatible with remnants of the vasa hyaloidea propria. The fundus had a tesselated appearance with angiographically visible large choroidal vessels. There was a retinochoroidal staphyloma inferotemporal to the optic disc. There were no retinal vessels visible temporally, and there was no macular differentiation or foveal pit. Competitive ELISA analysis disclosed no detectable serum endostatin. None of the 8 reported pathogenic mutations in the COL18A1 gene was found in the patient.

CONCLUSIONS

Persistent fetal vasculature may be a clinical and important manifestation in some patients with KS and can be explained by a deficiency in endostatin. Endostatin deficiency may result in reduced or delayed regression of fetal blood vessels in the eye (including the intravitreal compartment), thereby resulting in incomplete development of the normal vasculature in the retina. Our typing results for the reported COL18A1 mutations confirm the genetic heterogeneity of KS.