Inherited retinal dystrophies are a major cause of familial blindness.1
Inherited retinal dystrophies (IRDs) are a diverse group of degenerative eye diseases usually leading to eventual blindness.1
Inherited retinal dystrophies have overlapping signs and symptoms2–4
- Associated with >270 genes.5
The clinical classification of an IRD relies on a variety of features1:
- Primary target cell (cones vs rods);
- Primarily targeted retinal region (macula vs periphery);
- Age of onset and severity of visual impairment;
- Absence/presence of extra-retinal clinical involvement (isolated vs syndromic forms).
- Retinitis pigmentosa
- Leber congenital amaurosis
- Congenital stationary night blindness
- Achromatopsia (colour blindness)
- Stargardt disease
- Best disease
- Sorsby fundus dystrophy
- Usher syndrome
- Bardet-Biedl syndrome
The majority of patients (>50%) have vision impairment in early childhood.1,4,7
- Early-onset IRDs can progress quickly, leading to legal blindness in early adulthood.4,7
- IRDs result in progressive loss of rods and/or cones.1
Permit earlier intervention8
Improve accuracy of prognosis, decision-making and management8
IRD patients can exhibit:
Loss of visual acuity1,4,7
Young children: <20/200*
Adolescents/adults: 20/200 or worse
Restricted visual fields1,4,7
Patients may report that they have “tunnel vision”.
Parents may report young children bump into things in low light.
Reduced colour vision1,4,7
Nyctalopia; common aspect of a rod-cone dystrophy.
Difficulty with dark adaptation1,7,9
Light sensitivity (photophobia)7,9
Pigmentary changes, retinal atrophy, vessel attenuation, optic nerve pallor.
Lack of fundus autofluorescence1,4,7
Uncontrolled/repetitive eye movements.
Early onset in children (common aspect of a rod-cone dystrophy).
Failure to fix and follow10
Some IRDs can be syndromic and may affect other systems/organs.
For example, Usher syndrome also results in hearing loss.5
*Young children can often present with near-normal VA.
†This image was originally published in the Retina Image Bank. David Callan, MD. Retinitis Pigmentosa. Retina Image Bank. 2014;17341. © The American Society of Retina Specialists.
ERG, Electroretinogram; IRD, inherited retinal dystrophy; VA, visual acuity.
- Sahel JA Cold Spring Harb Perspect Biol 2015;5.2:a017111.
- Lee K and Garg S Genet Med 2015;17(4):245.
- Khan Z et al. Int J Adv Med 2016;1–8.
- Di Ioro V et al. Genes 2017;8:280–297.
- RetNet. https://sph.uth.edu/retnet/sum-dis.htm#A-genes (accessed March 2020).
- Nash BM et al. Transl Pediatr 2015;4(2):139.
- Chung D et al. Am J Ophthalmol 2019;199:58–70.
- American Academy of Ophthalmology®, IRD Clinical Statement. 2016. https://www.aao.org/clinical-statement/recommendations-on-clinica-lasses... (accessed March 2020).
- Fahim AT et al. 2000. https://www. ncbi.nlm.nih.gov/books/NBK1417/ (accessed March 2020).
- Cideciyan AV. Prog Retin Eye Res 2010;29(5):398–427.