cystoid macular edema

Retinitis Pigmentosa 77

Clinical Characteristics
Ocular Features: 

The onset of nyctalopia apparently varies from early childhood to 20 years of age and is usually the presenting symptom.  The loss of acuity is progressive (20/30 to 20/400) with older patients generally having more severe loss but there is little direct correlation with age.  Peripheral fields are progressively constricted, ranging from 10 to 30 degrees.  Some patients develop posterior subcapsular cataracts.  Retinal pigmentation is often mottled but 'bone spicules' are seen in about half of individuals.  Retinal vessels are narrowed.  The ERG shows generalized rod-cone dystrophy.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

Homozygous or compound heterozygous mutations in the REEP6 gene (19p13.3) are responsible for this disorder.  Five unrelated families have been reported.

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment has been reported although cataract removal may be visually beneficial.  

References
Article Title: 

Mutations in REEP6 Cause Autosomal-Recessive Retinitis Pigmentosa

Arno G, Agrawal SA, Eblimit A, Bellingham J, Xu M, Wang F, Chakarova C, Parfitt DA, Lane A, Burgoyne T, Hull S, Carss KJ, Fiorentino A, Hayes MJ, Munro PM, Nicols R, Pontikos N, Holder GE; UKIRDC., Asomugha C, Raymond FL, Moore AT, Plagnol V, Michaelides M, Hardcastle AJ, Li Y, Cukras C, Webster AR, Cheetham ME, Chen R. Mutations in REEP6 Cause Autosomal-Recessive Retinitis Pigmentosa. Am J Hum Genet. 2016 Dec 1;99(6):1305-1315.

PubMed ID: 
27889258

Familial Internal Retinal Membrane Dystrophy

Clinical Characteristics
Ocular Features: 

Folds in the internal limiting membrane are commonly seen, especially in the macula.  Intraretinal edema is seen throughout but may be most evident in the macula which often appears cystic.  Superficial microcystic changes in the retina are concentrated in the posterior pole.  The internal limiting membrane often appears thickened and filamentous material may be present in areas where it is separated from the retina.  The inner retina may have schisis cavities.  Visual acuity remains good until midlife.

This disorder is considered by some to result from a primary defect in Muller cells resulting in permeability defects on the retinal surface.  Evidence for this hypothesis comes from ERG studies in which light adapted responses showed a delayed and reduced b-wave, with broad and delayed ON and OFF responses and a missing flicker response.  However, responses may be inconsistent between the two eyes and more studies are needed.

Histologic studies show endothelial cell swelling, pericyte degeneration, and basement membrane thickening in retinal capillaries.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

Several families with transmission patterns characteristic of autosomal dominant inheritance have been reported.  However, no locus or mutation has been reported.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No effective treatment is available.

References
Article Title: 

Vitreoretinochoroidopathy

Clinical Characteristics
Ocular Features: 

Clinical features are variable in this ocular disorder. Small corneas and shallow anterior chambers have been described in some patients.  Chronic narrow angle glaucoma or frank angle closure glaucoma attacks may occur.  Microphthalmia has been reported but nanophthalmos has not been documented.  Presenile cataracts, nystagmus, and strabismus are sometimes present.  Some patients have normal vision but others have a severe reduction in acuity, even blindness.

The vitreous is often liquefied and some patients have a fibrillary vitreous with pleocytosis.  Preretinal white dots and neovascularization are often seen, even in children.  Peripapillary atrophy may extend to the macula which may have cystic edema.  Peripherally in annular fashion there is often a pigmentary retinopathy extending to an equatorial demarcation line at the posterior border.  The ERG is usually moderately abnormal with evidence of rod and cone dystrophy generally in older patients in which some degree of dyschromatopsia is often present.  Some patients demonstrate a concentric reduction in visual field that progresses with age.  A reduced light/dark ratio has also been documented in several families.  Retinal detachment is a risk.  A posterior staphylomas has been noted in a few patients. 

Systemic Features: 

No systemic abnormalities have been reported. 

Genetics

This is an autosomal dominant disorder resulting from mutations in BEST1 (11q13), which is also responsible for Best vitelliform macular dystrophy (153700). 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No prophylactic treatment has been reported but patients need lifelong monitoring to detect and treat glaucoma, retinal neovascularization, and detachments. 

References
Article Title: 

Mutations of VMD2 splicing regulators cause nanophthalmos and autosomal dominant vitreoretinochoroidopathy (ADVIRC)

Yardley J, Leroy BP, Hart-Holden N, Lafaut BA, Loeys B, Messiaen LM, Perveen R, Reddy MA, Bhattacharya SS, Traboulsi E, Baralle D, De Laey JJ, Puech B, Kestelyn P, Moore AT, Manson FD, Black GC. Mutations of VMD2 splicing regulators cause nanophthalmos and autosomal dominant vitreoretinochoroidopathy (ADVIRC). Invest Ophthalmol Vis Sci. 2004 Oct;45(10):3683-9.

PubMed ID: 
15452077
Subscribe to RSS - cystoid macular edema