Retinal dystrophies

Purpose Review of typical clinical pictures and gene defects associated with most prevalent retinal dystrophies such as retinitis pigmentosa, Stargardt's macular dystrophy, Best's macular dystrophy, cone dystrophy, congenital stationary night blindness, pattern dystrophy and some rarer types of dystrophies. Methods Clinical methodology to diagnose retinal dystrophies is based on conventional perimetry, microperimetry, autofluorescence imaging, OCT and electrophysiology. The use of these methods will be outlined in characteristic cases. Genetic testing is necessary to characterise the genetic cause of these diseases as clinical heterogeneity is large. Results Autofluorescence imaging and OCT non‐invasively reveal typical morphological patterns of different retinal dystrophies, for which fluorescein angiography is not necessary. Different electrophysiological methods (photopic/scotopic ERG, pattern ERG, multifocal ERG, visual evoked potentials) determine function of retinal layers and the macula. Residual retinal function and progression of the disease can thus be objectively assessed and followed‐up. In initial stages when retinal changes may not be visible, electrophysiological features can reveal the site of dysfunction and dissociate it form putative optic nerve disease. Conclusion The residents should be aware of the differential diagnosis of retinal dystropies and be able to dissociate between them. Also, typical genetic transmission and genetic counseling is important for the information that is given to the patient. Residents should be aware of treatable associated features of retinal dystrophies such as cataract or cystoid macular edema or glaucoma.