anterior synechiae

Corneal Dystrophy, Posterior Polymorphous 4

Clinical Characteristics
Ocular Features: 

The posterior corneal surface becomes highly irregular as the endothelial cells become variable in size and in number.  There may be focal areas of multilayering of endothelial cells.  Most patients have a significant reduction in endothelial cell density which eventually leads to corneal edema and blurred vision.  Some patients have anterior synechiae and corectopia with secondary glaucoma.

Corneal edema has been noted in infants at several months of age.  Painful bullous keratopathy or uncontrollable glaucoma may lead to enucleation in adult life.

Systemic Features: 

The posterior corneal surface becomes highly irregular as the endothelial cells become highly irregular in size and in number.  There may be focal areas of multilayering of endothelial cells.  Most patients have a significant reduction in endothelial cell density which eventually leads to corneal edema and blurred vision.  Some patients have anterior synechiae and corectopia with secondary glaucoma.

Corneal edema has been noted in infants at several months of age.  Painful bullous keratopathy or uncontrollable glaucoma may lead to enucleation in adult life.

Genetics

Heterozygous mutations in the GRHL2 gene (8q22.3-q24.12) are responsible for this condition.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Corneal transplantation may benefit selected patients.E

References
Article Title: 

Ectopic GRHL2 Expression Due to Non-coding Mutations Promotes Cell State Transition and Causes Posterior Polymorphous Corneal Dystrophy 4

Liskova P, Dudakova L, Evans CJ, Rojas Lopez KE, Pontikos N, Athanasiou D, Jama H, Sach J, Skalicka P, Stranecky V, Kmoch S, Thaung C, Filipec M, Cheetham ME, Davidson AE, Tuft SJ, Hardcastle AJ. Ectopic GRHL2 Expression Due to Non-coding Mutations Promotes Cell State Transition and Causes Posterior Polymorphous Corneal Dystrophy 4. Am J Hum Genet. 2018 Mar 1;102(3):447-459.

PubMed ID: 
29499165

Retinal Nonattachment, Congenital

Clinical Characteristics
Ocular Features: 

The common denominator in this condition is, of course, congenital nonattachment of the retina.  Many eyes are small as well.  Some patients in addition have a vascularized hyperplastic vitreous and often present with blindness and a congenital leukocoria.  Many at some stage have lens opacification, as well as glaucoma and anterior chamber anomalies including anterior synechiae and some degree of corneal opacification.  These signs are often progressive beginning in childhood.  Pendular nystagmus and esotropia are common.  MRI studies reveal optic nerves and the chiasm that are either absent or abnormally small.

Systemic Features: 

This condition is nonsyndromic and has no systemic abnormalities.

Genetics

Congenital retinal nonattachment consists of a group of sometimes familial conditions for which no responsible gene has been identified.  In a genomic study of 21 consanguineous NCRNA Pakistani families 3 had mutations in ATOH7 and 10 had mutations in familial exudative vitreoretinopathy genes.  Genotyping did not reveal associated mutations in the remaining 38% of these families. It is likely that multiple entities are represented but until the molecular etiologies are identified, no more specific classification is possible.

Studies in mice document that the Atoh7 gene is important to retinal ganglion cell neurogenesis.  In humans, both autosomal recessive PHPV and congenital nonattachment of the retina are associated with microsatellite linkage and haplotype matching to a region at 10q21 adjacent to the ATOH7 gene but so far no causative mutation has been found in this region.  However, studies in large consanguineous kindreds in which a deleted DNA segment adjacent to ATOH7 segregated with the NCRNA phenotype suggest that a transcription regulator may be at fault in the timing and level of ATOH7 expression.

The disorder known as persistent hyperplastic primary vitreous is generally not considered hereditary since it usually occurs unilaterally and sporadically.  It is sometimes found in association with a number of syndromal conditions as well.  However, it has also been reported in familial patterns consistent with both autosomal recessive and autosomal dominant patterns.  DNA mapping of individuals with bilateral disease found in a consanguineous Pakistani kindred with presumed autosomal recessive disease suggests that a locus at 10q11-q21 may be responsible.

Evidence for autosomal dominant inheritance of persistent hyperplastic primary vitreous comes from rare families with an apparent vertical transmission of the condition.

Congenital nonattachment of the retina is also seen in the osteoporosis-pseudoglioma syndrome (250770).  However, this is a syndromal disorder with neurologic and joint disease in addition to porotic, thin, fragile bones (sometimes called the ocular form of osteogenesis imperfecta) resulting from mutations in LRP5 on chromosome 11.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

With rare exceptions, the retina cannot be reattached successfully and phthisis with blindness is the usual outcome.

References
Article Title: 

Anterior Segment Mesenchymal Dysgenesis

Clinical Characteristics
Ocular Features: 

The unique status of this entity remains to be established as there are overlapping features with aniridia (106210), and Peters anomaly (604229), posterior embryotoxon, and iridogoniodysgenesis type 1 (601631) and type 2 (137600).  Anterior segment mesenchymal dysgenesis itself is clinically heterogeneous even within families.  Schwalbe line is often anteriorly placed and there may be iris adhesions to the cornea, with or without corneal opacities.  Some patients have microcornea.  All layers of the cornea are dysplastic from the epithelium to the endothelium suggesting abnormal migration or function of neural crest cells.  Lens opacities are highly variable but they can be progressive. Curiously, elevated intraocular pressure is usually not present.  Visual acuity is highly variable with some patients having 20/20 vision and others bare hand motions depending on the degree of opacification of the lens and cornea.

Systemic Features: 

No systemic abnormalities are present.

Genetics

This is an autosomal dominant disorder secondary to mutations in either PITX3 (10q24.32) or FOXE3 (1p32)  which are both transcription factors.  The latter gene is also mutant in congenital primary aphakia (610256) and some cases of Peters anomaly (604229).

See also Anterior Segment Dysgenesis 6 (617315) and Anterior Segment Dysgenesis 8 (617319) for autosomal recessive conditions in which mutations result in malformations of the anterior chamber.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Cataract surgery is indicated in some cases and corneal transplantation has been attempted in a few individuals.

References
Article Title: 

Histiocytic Dermatoarthritis

Clinical Characteristics
Ocular Features: 

This disorder has some ocular similarities to dermochondrocorneal dystrophy of Francois (221800) such as the presence of cataracts, but differs in the absence of corneal opacities.  All patients examined have had glaucoma, uveitis and lens opacities.  Gonioscopy in one patient showed multiple anterior synechiae and another patient, an adult, had buphthalmos.

Systemic Features: 

Skin lesions and stiff, painful joints develop between 4 and 15 years of age.   The cutaneous nodules are found primarily on the hands, ears and the upper extremities.  These are nonulcerating, tender, violaceous to brown in color, and firm in consistency.  Firm subcutaneous plaques apparent only on palpation are also present.  No mucosal lesions or xanthelasmata are present.  Deforming, symmetric arthritis of the hands, feet and elbows is frequently seen with periarticular bony resorption.  The skin of the legs and feet are thick and lichenified.  Histology of the skin lesions shows a granulomatous appearance with a chronic inflammatory infiltrate.  No multinucleated giant cells are seen.

Genetics

A single family with 4 affected sibs born to an affected male parent has been reported which suggests autosomal dominant inheritance.  The mutation, if any, is unknown.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

The glaucoma should, of course, be treated but no treatment is available for the systemic disease beyond orthopedic correction of the joint deformities.

References
Article Title: 

Axenfeld-Rieger Syndrome, Type 2

Clinical Characteristics
Ocular Features: 

As in RIEG1 and RIEG3, glaucoma is the most serious ocular problem.  In a large family with 11 affected members, 9 had glaucoma.  All had the classic ocular signs of anterior segment dysgenesis, primarily posterior embryotoxon and iris adhesions (for a full description of the ocular features see Axenfeld-Rieger syndrome, RIEG1 [180500]).

Systemic Features: 

Oligodontia, microdontia, and premature loss of teeth are common in type 2.  Maxillary hypoplasia is less common as is hearing loss.  Umbilical anomalies were not present in any affected individuals.  Cardiac defects are rare.

Genetics

This is an autosomal dominant disorder as in the other types.  The locus is at 13q14 but no molecular defect has been defined.  At least two individuals purported to have type 2 were found to have deletions of this segment of chromosome 13.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

The high risk of glaucoma demands lifelong monitoring of intraocular pressure.

References
Article Title: 

Corneal Dystrophy, Posterior Polymorphous 1

Clinical Characteristics
Ocular Features: 

This form of corneal dystrophy is often asymptomatic but some patients experience endothelial decompensation and corneal edema, which may even be seen soon after birth. The edema may extend into the epithelium.  The basic mechanism entails metaplasia of endothelial cells which seem to acquire some characteristics of epithelial cells.  Posterior corneal lesions of variable morphology appear in various patterns and are often surrounded by grayish halos.  When these become confluent the corneal edema is more severe and may resemble a congenital endothelial dystrophy.  The endothelial cell count is often low.  The Descemet layer also becomes abnormal.  The posterior border of the cornea appears nodular and grayish in color, often in a geographic pattern.  Surprisingly, endothelial function often is maintained and patients may remain asymptomatic for many years.

Some patients have features of anterior chamber dysgenesis with iris anomalies, anterior synechiae, and glaucoma.  It is also sometimes confused with EDICT syndrome (614303).

Systemic Features: 

No systemic disease is associated with this disorder.

Genetics

This is a genetically heterogeneous autosomal dominant disorder caused by several mutations including the promotor of OVOL2 at 20p11.23 responsible for PPCD1 described here.  Another locus for this disease has been mapped to 20q11, the same locus responsible for congenital hereditary corneal edema 1 (CHED1) and it is possible that these are allelic or clinical variants of the same mutation.  The latter is made more likely by the fact that both disorders have been found in relatives.  OMIM has combined the entities CHED1 and PPCD1 as a single disorder (122000).

For other forms of posterior polymorphous corneal dystrophy see, PPCD2 (609140) and PPCD3 (609141).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Few patients require treatment since the endothelial changes are frequently stable. Among those that do undergo corneal transplantation, the changes often recur in the donor button.

References
Article Title: 

Strømme Syndrome

Clinical Characteristics
Ocular Features: 

The core complex of Stromme syndrome consists of intestinal atresia and ocular abnormalities of the anterior segment.  The ocular anomalies consist of variable amounts of angle dysgenesis, anterior synechiae, corneal leukoma, iris colobomas and hypoplasia, sclerocornea, cataracts, and sometimes microcornea.  However, microphthalmia, tortuous retinal vessels, and optic nerve hypoplasia may also be present.  Hypertelorism and deep-set eyes have been described.  Glaucoma has not been reported.  Only about 10 cases have been reported since Stromme 's first report in 1993.  Most patients have been too young for reliable acuity testing. 

Systemic Features: 

The phenotype is highly variable.  The ears are often large and low-set.  Microcephaly is often present along with a cleft palate and micrognathia.  The intestinal atresia seems to involve the jejunum primarily and is usually surgically correctable.  The duodenum may also be involved and intestinal malrotation has been described.  Myopathic changes in the myocardium have been seen along with small cardiomyoctes.  Microcephaly seems to be progressive.  Short stature has been noted and the amount of developmental delay is highly variable.  Renal hypodysplasia and hydronephrosis have been described.

Some patients seem to develop and function almost normally while more severely affected individuals may not live beyond early infancy or childhood.

Genetics

Compound heterozygous mutations in the CENPF gene (1q41) segregate with this condition. 

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Infants do well following intestinal surgery.  Ocular surgery has not been reported.

References
Article Title: 

Stromme Syndrome: New Clinical Features

Stromme Syndrome: New Clinical Features Bayram Ali Dorum, Irmak Tanal Sambel, Hilal Ozkan, Irfan Kiristioglu, Nilgun Koksal APSP J Case Rep. 2017 Mar-Apr; 8(2): 14. Published online 2017 Mar 18.

PubMed ID: 
5371687

Stromme Syndrome is a Ciliary Disorder Caused by Mutations in CENPF

Filges I, Bruder E, Brandal K, Meier S, Undlien DE, Waage TR, Hoesli I, Schubach M, de Beer T, Sheng Y, Hoeller S, Schulzke S, Rosby O, Miny P, Tercanli S, Oppedal T, Meyer P, Selmer KK, Stromme P. Stromme Syndrome is a Ciliary Disorder Caused by Mutations in CENPF. Hum Mutat. 2016 Jan 28. doi: 10.1002/humu.22960. [Epub ahead of print].

PubMed ID: 
26820108

Peters Anomaly

Clinical Characteristics
Ocular Features: 

Peters anomaly occurs as an isolated malformation but also as a feature of other syndromes.  It is often unilateral.  A wide variety of other ocular findings may occur with Peters anomaly as well. Here we limit our description to 'simple' Peters anomaly in which the findings are limited to the eye having the classic findings of adhesions of the iris to the posterior cornea and a central or paracentral corneal leukoma.  The lens may also be adherent to the cornea and is often opacified to some degree.  Descemet's membrane and portions of the posterior stroma are usually missing as well.  Glaucoma is frequently present.  Importantly, there is a wide range in the presentation of clinical features.

Systemic Features: 

Peters anomaly is a frequent feature of numerous syndromes, both ocular and systemic, among them the Peters-plus (261540) syndrome (sometimes called the Kivlin-Krause (261540) syndrome) and has been reported in a case with aniridia (106210).

Genetics

Isolated Peters anomaly usually occurs in an autosomal recessive pattern but autosomal dominant patterns have been reported as well.  The recessive disorder may be caused by a mutation in several genes, notably PAX6, PITX2,  CYP1B1, FOXC1, and FOXE3.  The latter gene is also mutated in anterior segment mesenchymal dysgenesis (107250) and congenital primary aphakia (610256).  The variety of clinical features are likely the result of a disruption in some common pathway or pathways.  Mutations in B3GALTL associated with the Peters-Plus syndrome have not been identified in isolated Peters anomaly.

This is a genetically and clinically heterogeneity condition as whole genome sequencing reveals numerous additional gene mutations in patients with both syndromic and isolated Peters anomaly.

PITX2 is also mutated in ring dermoid of the cornea (180550) and in Axenfeld-Rieger syndrome type 1 (180500).  PAX6 mutations also cause diseases of the cornea, fovea, optic nerve and iris.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Glaucoma is the most serious threat to vision on Peters anomaly but also the most difficult to treat.  Less than a third of patients achieve control of intraocular pressure even with the most vigorous combinations of therapy.  Corneal opacities can be treated with transplantation but the prognosis is often guarded when glaucoma is present.

From eye bank and other data, it has been estimated that 65% of penetrating keratoplasties in infants for visually significant congenital corneal opacities are performed in patients with Peters anomaly. 

References
Article Title: 

Whole exome sequence analysis of Peters anomaly

Weh E, Reis LM, Happ HC, Levin AV, Wheeler PG, David KL, Carney E, Angle B, Hauser N, Semina EV. Whole exome sequence analysis of Peters anomaly. Hum Genet. 2014 Sep 3. [Epub ahead of print].

PubMed ID: 
25182519

Peters-Plus Syndrome

Clinical Characteristics
Ocular Features: 

Peters anomaly (306229) usually occurs as an isolated ocular malformation and is often unilateral.  However, in some patients with bilateral involvement it is part of a systemic syndrome or other congenital conditions such as chromosomal deletions and the fetal alcohol syndrome.  It is called Peters Plus syndrome in the condition described here because of the association of a specific combination of systemic features.

The ocular features are consistent with dysgenesis of the anterior chamber.  The clinical picture is highly variable but generally consists of iris adhesions to the cornea centrally (classical Peters anomaly), occasionally lenticular adhesions as well, and thinning of the central corneal stroma.  As a result, the cornea may become edematous, cataracts may develop, and glaucoma is common.

Systemic Features: 

Peters-plus syndrome consists of Peters anomaly plus various degrees of developmental delays and intellectual deficits, short digits and short stature, and cleft lip and palate.  The facies is said to be characteristic due to a prominent forehead, narrow palpebral fissures, and a cupid's bow-shaped upperlip. There may be preauricular pits present and the neck is often broad.  The ears may be prominent.  Congenital heart defects are present in a third of patients and a few have genitourinary anomalies.

Genetics

This is an autosomal recessive disorder of glycosylation caused by a mutation in the B3GALTL gene on chromosome 13 (13q12.3).  At least some patients have a splicing mutation in this gene leading to a skipping of exon 8.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Treatment is directed at sight preservation by correcting the major ocular defects such as glaucoma and iridocorneal adhesions.  Corneal transplants and cataract removal are sometimes required.  Releasing the anterior synechiae can lead to significant clearing of the corneal edema.  Growth hormone replacement therapy may be beneficial.

References
Article Title: 

The Peters' plus syndrome: a review

Maillette de Buy Wenniger-Prick LJ, Hennekam RC. The Peters' plus syndrome: a review. Ann Genet. 2002 Apr-Jun;45(2):97-103. Review.

PubMed ID: 
12119218

Sclerocornea

Clinical Characteristics
Ocular Features: 

This is a disorder of the cornea and anterior chamber that is sometimes considered to be a form of anterior segment or mesenchymal dysgenesis.  The primary feature is corneal clouding, most prominent peripherally and extending to the central cornea to a variable extent.  Vascular arcades are usually present over the area of clouding and there is no clear limbal demarcation.  Corneal fibers are often disorganized and larger than normal.  The anterior chamber may appear shallow and the iris usually has a flat appearance, often with a posterior embryotoxon.  Iris processes to the cornea and anterior synechiae are frequently present.  Some degree of microcornea has also been noted in many cases.  Rotary and horizontal nystagmus are uncommon. Sclerocornea may be a feature of cornea plana as well and the distinction between these disorders is unclear, especially in reported dominant pedigrees in which hyperopia is a feature.

Most cases are bilateral but there is often considerable asymmetry between the two eyes.  Visual acuity is dependent on the extent of corneal opacification but may be normal.  It is not a progressive disease.

Systemic Features: 

No systemic abnormalities have been reported.  However, sclerocornea can be a feature of numerous somatic and chromosomal disorders (e.g., oculocerbral syndrome with hypopigmentation (257800 ).

Genetics

No DNA mutations have as yet been found.  Most cases occur sporadically, and others are part of anterior chamber dysgenesis disorders.  However, rare autosomal dominant pedigrees have been reported in which the degree of opacification and anterior chamber anomalies are not as severe as those in which the pattern is most consistent with autosomal recessive inheritance.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Severe cases in which the central media is compromised may require corneal transplantation.  Glaucoma requires treatment as well.

References
Article Title: 

A review of anterior

Idrees F, Vaideanu D, Fraser SG, Sowden JC, Khaw PT. A review of anterior
segment dysgeneses. Surv Ophthalmol. 2006 May-Jun;51(3):213-31. Review.

PubMed ID: 
16644364

Hereditary sclerocornea

Elliott JH, Feman SS, O'Day DM, Garber M. Hereditary sclerocornea. Arch
Ophthalmol. 1985 May;103(5):676-9.

PubMed ID: 
3994576

Pages

Subscribe to RSS - anterior synechiae