retinal avascularity

Familial Exudative Vitreoretinopathy, EVR7

Clinical Characteristics
Ocular Features: 

The ocular features are primarily limited to the posterior chamber where there are areas of retinal avascularity, exudation, retinal holes, and detachments.  Areas of degeneration and pigmentary retinopathy may be present.  Vascular proliferation may be part of the process with vitreous traction and folds.  Progression of retinal damage is highly variable and surgical outcomes are unpredictable.  Long term vision outcomes are sometimes as good as 20/40 but in many eyes NLP or hand motion vision is the end result.  

Secondary changes in the anterior chamber and cornea from repeated surgeries may lead to glaucoma, cataracts, and corneal decompensation. 

Systemic Features: 

There are no consistent systemic abnormalities.

Genetics

Missense and nonsense heterozygous mutations in the CTNNB1 gene (3p22.1) segregate with this autosomal dominant condition found in two families of Japanese origin.  A Chinese 3-year-old with FEVR having a single BP insertion in the CTNNB1 gene also had global developmental delay and dysmorphic facies.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

The prognosis for vision is poor as the retinal damage often continues to evolve and additional folds and detachments develop.  Attempts to close retinal holes and repair detachments are important.

References
Article Title: 

Defects in the Cell Signaling Mediator β-Catenin Cause the Retinal Vascular Condition FEVR

Panagiotou ES, Sanjurjo Soriano C, Poulter JA, Lord EC, Dzulova D, Kondo H, Hiyoshi A, Chung BH, Chu YW, Lai CHY, Tafoya ME, Karjosukarso D, Collin RWJ, Topping J, Downey LM, Ali M, Inglehearn CF, Toomes C. Defects in the Cell Signaling Mediator v-Catenin Cause the Retinal Vascular Condition FEVR. Am J Hum Genet. 2017 Jun 1;100(6):960-968.

PubMed ID: 
28575650

Familial Exudative Vitreoretinopathy, EVR2

Clinical Characteristics
Ocular Features: 

The basis for many of the ocular complications likely begins with incomplete development of the retinal vasculature.  Resulting retinal ischemia leads to neovascularization, vitreous hemorrhage and traction, and retinal folds, with some 20% going on to develop rhegmatogenous or traction detachments.  There is, however, considerable clinical variability, even within families, with some infants blind from birth whereas some (41%) adults have only areas of remaining avascularity or evidence of macular dragging.  In fact, some affected individuals are asymptomatic and diagnosed only as part of extensive family studies.  Intraretinal lipid is often seen.  Considerable asymmetry in the two eyes is common.  Secondary cataracts often occur and phthisis bulbi results in some patients.  The clinical picture is sometimes confused with retinopathy of prematurity.

Systemic Features: 

No consistent systemic abnormalities have been identified in EVR2.

Genetics

Familial exudative vitreoretinopathy is the name given to a clinically and genetically heterogeneous group of disorders caused by mutations in several genes.  Autosomal dominant (e.g., EVR1; 133780), and X-linked inheritance (this condition) have been reported with the former much more common. 

The X-linked form of FEVR (EVR2 described here) results from mutations in the NDP gene (Xp11.3) and is allelic to Norrie disease (310600).

Retinopathy of prematurity can be called a phenocopy of FEVR.

Pedigree: 
X-linked recessive, carrier mother
X-linked recessive, father affected
Treatment
Treatment Options: 

Retinal, vitreal, and cataract surgery are indicated in appropriate cases.

References
Article Title: 

Familial Exudative Vitreoretinopathy, EVR4

Clinical Characteristics
Ocular Features: 

The basis for many of the ocular complications likely begins with incomplete development of the retinal vasculature.  Resulting retinal ischemia leads to neovascularization, vitreous hemorrhage and traction, and retinal folds with some 20% going on to develop rhegmatogenous or traction detachments.  There is, however, considerable clinical variability, even within families, with some infants blind from birth whereas some (41%) adults have only areas of remaining avascularity or evidence of macular dragging.  In fact, some affected individuals are asymptomatic and diagnosed only as part of extensive family studies.  Intraretinal lipid is often seen.  Considerable asymmetry in the two eyes is common. Secondary cataracts often occur and phthisis bulbi results in some patients.  The clinical picture is sometimes confused with retinopathy of prematurity.

Systemic Features: 

Osteoporosis and endosteal hyperostosis has been reported among individuals with mutations in LRP5.

Genetics

The EVR4 form of FEVR results from mutations in the LRP5 gene (11q13.4) and the clinical features may be seen in both heterozygotes and homozygotes.  Thus the disease is inherited in both autosomal dominant and autosomal recessive patterns.  The osteoporosis-pseudoglioma syndrome (259770) is allelic to this condition.

Mutations in the FZD4 gene cause a phenotypically indistinguishable condition (EVR1; 133780) but is always inherited in an autosomal dominant pattern.  There is also an X-linked form (EVR2) caused by a mutation in NDP (305390).

Retinopathy of prematurity can be called a phenocopy of FEVR.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Retinal, vitreal, and cataract surgery are indicated in appropriate cases.

References
Article Title: 

Familial Exudative Vitreoretinopathy, EVR1

Clinical Characteristics
Ocular Features: 

The basis for many of the ocular complications likely begins with incomplete development of the retinal vasculature.  Resulting retinal ischemia leads to neovascularization, vitreous hemorrhage and traction, and retinal folds, with some 20% going on to develop rhegmatogenous or traction detachments.  There is, however, considerable clinical variability, even within families, with some infants blind from birth whereas some (41%) adults have only areas of remaining avascularity or evidence of macular dragging.  In fact, some affected individuals are asymptomatic and diagnosed only as part of extensive family studies.  Intraretinal lipid is often seen.  Considerable asymmetry in the two eyes is common.  Secondary cataracts often occur and phthisis bulbi results in some patients.  The clinical picture is sometimes confused with retinopathy of prematurity.

Systemic Features: 

No systemic features have been associated with EVR1 disease.

Genetics

Familial exudative vitreoretinopathy is the name given to a clinically and genetically heterogeneous group of disorders caused by mutations in several genes.  Both autosomal dominant (EVR1 described here) plus EVR4 (601813) and X-linked inheritance (EVR2; 305390) have been reported with the former much more common.  Similarities in the clinical presentation of Congenital Nonattachment of the Retina may cause diagnotic confusion. 

Mutations in the frizzled-4 gene FZD4 (11q14-q21) have been associated with the EVR1 form of this disease inherited in an autosomal dominant pattern.  Retinopathy of prematurity can be called a phenocopy of FEVR.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Retinal, vitreal, and cataract surgery are indicated in appropriate cases.

References
Article Title: 
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