loss of vision

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

Corneal Dystrophy, Band-Shaped

Clinical Characteristics
Ocular Features: 

Symptoms of ocular irritation with tearing, conjunctival injection and decreased vision can be present at birth but more often is evident later in the first decade of life.  The band is located in the cornea in the palpebral fissure area in a horizontal pattern.  Apparently no other lesions are present in the eye.    

Systemic Features: 

None reported.

Genetics

Only three families with familial, isolated band keratopathy have been reported.  These were described in the mid-twentieth century and it is possible that they had underlying ocular and corneal disease.  In one family 3 of 9 children, the product of a first-cousin mating, were affected consistent with autosomal recessive inheritance.  In two of these the keratopathy was first noted during puberty while it was present at birth in the third child.

 In another family the band keratopathy was seen in a brother and sister at 11 and 16 years old.

In the third family a father and son were affected.

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Topically applied EDTA solutions are sometimes effective in removing lesions consisting of calcium deposits but this has not been reported to be effective in the hereditary form of band keratopathy. 

References
Article Title: 

Flecked Retina Syndromes

Clinical Characteristics
Ocular Features: 

There exist a considerable number of disorders often classified under the heading of 'flecked retina' syndrome.  Prior to the modern genomic period, distinctions among them were based on the clinical picture, functional abnormalities, and electrophysiological studies.  The nosology is becoming clearer as more individuals are genotyped and we can expect further discrimination of these disorders in the near future.

White or yellow discrete dots are found throughout the fundus.  These are most dense in the midperiphery RPE and the macula is generally not involved.  This is most common in patients with fundus albipunctatus who have a nonprogressive disease.  Stationary night blindness is the predominant symptom.  However, patients with mutations in RDH5 may have more serious cone involvement and progressive macular disease.  Visual acuity varies from near normal to severe loss.  Photopic ERGs may be normal but only low scotopic responses can be recorded in such patients.  Cone dysfunction is more severe in older patients.

Systemic Features: 

No systemic disease is associated with these syndromes.

Genetics

These disorders are sometimes grouped into the category of 'flecked retina disease'.

Autosomal dominant inheritance is typical for fundus albipunctatus (136880) resulting from mutations in the RDS (PRPH2) gene (6p21.1-cen).

Autosomal recessive fundus albipunctatus (136880) is caused by mutations in RDH5 (12q13-q14) and sometimes in RLBP1 (15q26.1).

Retinitis punctata albescens (136880) and fundus albipunctatus (136880) may both be caused by mutations in RLBP1 (15q26.1).  In a consanguineous family in which younger individuals (aged 3-20 years) had signs of fundus albipunctatis, older individuals in the fourth and fifth decades of life had features of retinitis punctata albescens (136880).  Homozygous mutations in RLBP1 were found in all individuals.  Homozygous mutations in the same gene are also responsible for Bothnia type retinal dystrophy (607475) and for the Newfoundland type of retinal dystrophy (607476).

Familial Benign Fleck Retina (228980) is characterized by a normal ERG and normal vision. The macula is spared from the white/yellow flecks located behind retinal vessels. Autofluorescence is present and the fluorescein angiogram shows irregular hypofluorescence.  Nothing is known about the mutation but the clinical condition is inherited in an autosomal recessive pattern.

Some group Stargardt disease (248200), fleck retina of Kandori (228990),  juvenile retinoschisis (312700), and familial benign fleck retina (228980) as well into the category of 'flecked retina disease'.

Other disorders in which retinal flecks may be seen are: spastic paraplegia 15 (270700), hyperoxaluria (259900), Alport syndrome (301050), Bietti-crystalline-corneoretinal-dystrophy (210370 ), Sjogren-Larsson syndrome (270200), pantothenate kinase-associated neurodegeneration (234200), Leber congenital amaurosis (204000), and Bardet-Biedl syndrome (209900),

Pedigree: 
Autosomal dominant
Autosomal recessive
Treatment
Treatment Options: 

Low vision aids may be useful when macular disease is present.  A recent report describes improvement in peripheral fields and rod function following administration of high-dose oral 9-cis-beta-carotene.

References
Article Title: 

Flecked-retina syndromes

Walia S, Fishman GA, Kapur R. Flecked-retina syndromes. Ophthalmic Genet. 2009 Jun;30(2):69-75..

PubMed ID: 
19373677

Novel mutations in the cellular retinaldehyde-binding protein gene (RLBP1) associated with retinitis punctata albescens: evidence of interfamilial genetic heterogeneity and fundus changes in heterozygotes

Fishman GA, Roberts MF, Derlacki DJ, Grimsby JL, Yamamoto H, Sharon D, Nishiguchi KM, Dryja TP. Novel mutations in the cellular retinaldehyde-binding protein gene (RLBP1) associated with retinitis punctata albescens: evidence of interfamilial genetic heterogeneity and fundus changes in heterozygotes. Arch Ophthalmol. 2004 Jan;122(1):70-5.

PubMed ID: 
14718298

Benign fleck retina

Isaacs TW, McAllister IL, Wade MS. Benign fleck retina. Br J Ophthalmol. 1996 Mar;80(3):267-8. PubMed PMID: 8703867

PubMed ID: 
8703867
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