Macular Edema, Autosomal Dominant Cystoid

Clinical Characteristics
Ocular Features: 

Only a few families have been reported.  The macular edema can be traced to retinal capillary leakage throughout the posterior pole as revealed by fluorescein angiography.  Scattered exudates and nerve fiber layer hemorrhages are sometimes seen.  Hyperopia and strabismus are often present as well.  Veils, strands, and white punctate deposits in the vitreous have been described.  Wrinkling of the internal limiting membrane may be present.  The ERG is normal except for elevated rod dark adaptation thresholds.  Light/dark ratios are abnormal on EOG testing and mild dyschromatopsia can be demonstrated.  Patients usually notice problems with their visual acuity in the second decade of life and it can drop to 20/200 at this time with progression to 2/120 - 2/200 in older individuals.  In later stages of the disease a central zone of beaten bronze macular atrophy can be seen.  Surrounding this central atrophy is often an area with pigmentary changes resembling retinitis pigmentosa which can extend into the periphery.

This would seem to be a unique disorder in spite of some similarities to retinitis pigmentosa in which macular cysts are often seen.  The clinical course is distinctly different and the presence of vitreous deposits and hyperopia also can be used as arguments for its separateness.  Molecular DNA evidence showing lack of allelism (Vida infra) is, of course the strongest evidence.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

This autosomal dominant form of progressive macular dystrophy is linked to a locus at 7p21-p15.  The mutation is close to the RP9 locus causing one type of retinitis pigmentosa but linkage analysis shows the two disorders to be non-allelic.

Treatment
Treatment Options: 

No specific treatment is available for the macular disease but low vision aids are likely useful, at least early in the disease.

References
Article Title: 

References

Inglehearn C, Keen TJ, al-Maghtheh M, Bhattacharya S. Loci for autosomal dominant retinitis pigmentosa and dominant cystoid macular dystrophy on chromosome 7p are not allelic. Am J Hum Genet. 1994 Sep;55(3):581-2.

PubMedID: 8079997

Fishman GA, Goldberg MF, Trautmann JC. Dominantly inherited cystoid macular edema. Ann Ophthalmol. 1979 Jan;11(1):21-7.

PubMedID: 420475

Notting JG, Pinckers JL. Dominant cystoid macular dystrophy. Am J Ophthalmol. 1977 Feb;83(2):234-41.

PubMedID: 836665