Gyrate Atrophy

Gyrate Atrophy
SYMPTOMS Nyctalopia, Vision loss, Visual field defects, Color vision defects
SIGNS Bilateral
Small areas of chorioretinal atrophy with scalloped borders that start in the mid-peripheral retina and will eventually coalesce into larger areas of chorioretinal atrophy and spread to the far periphery and posterior pole (the macula is affected last), RPE clumping, Loss of choroidal vasculature which exposes the sclera, Posterior subcapsular cataracts, Cystoid macular edema
WORK-UP Pupils, Color vision (abnormal), Full eye exam with dilation, Visual field, OCT of the macula, OCT-Angiography (presence of choriocapillaris loss), Fundus Autofluorescence, Fluorescein Angiography (presence of choriocapillaris loss), Indocyanine Green Angiography (presence of choriocapillaris loss), Fundus photos, Infrared photos, Electrodiagnostic testing (ERG: Abnormal / EOG: Abnormal), Dark adaptation (abnormal), Watzke-Allen test, Macular photostress test, Amsler grid
TREATMENT Give take home Amsler grid in order to monitor for macula involvement
Gyrate atrophy without cystoid macular edema: Monitor
Refer to PCP to monitor levels of ornithine
Recommend a low protein diet (especially low arginine). Patient should follow-up with their PCP
Recommend Vitamin B6 supplementation. Patient should follow-up with their PCP
Recommend genetic counseling for other family members
If the patient develops poor vision, refer to low vision
Gyrate atrophy with cystoid macular edema: Refer to a retinal specialist ASAP for further evaluation and treatment
If the patient presents with a visual significant posterior subcapsular cataract, refer for cataract surgery
FOLLOW-UP If monitoring, the patient should be seen back in 6-12 months
After patient is evaluated and treated by a retinal specialist and the retina/macula is stable, the patient should be seen back every 6 months
ADDITIONAL LAB | TESTS Genetic testing, Serum levels of ornithine
ETIOLOGY Autosomal recessive progressive retinal dystrophy that occurs due to a mutation in ornithine amino transferase which leads to increased levels of ornithine (10-20 times more than normal) which causes damage to the photoreceptors, RPE, and choroid
DIFFERENTIAL DX Retinitis pigmentosa, Choroideremia, “Salt and pepper" fundus, Ocular albinism
NOTES Symptoms are typically first noted during the first decade of life. Central vision loss typically occurs during the fourth or fifth decade of life
Gyrate atrophy is associated with myopia 80% of the time
Gyrate atrophy can be associated with delayed development and reduced cognitive ability. Thin, sparse hair and muscular atrophy can also be associated with gyrate atrophy