Decreased vision in childhood or young adulthood. Early in the disease, the decrease in vision is often out of proportion to the clinical ophthalmoscopic appearance; therefore, care must be taken not to label the child a malingerer.

(See Figures 11.30.1 to 11.30.3.)

Figure 11.30.1: Stargardt disease.

Figure 11.30.2: Intravenous fluorescein angiography of Stargardt disease exhibiting silent choroid.

Figure 11.30.3: Fundus autofluorescence in Stargardt disease.

Critical

Any of the following may be present.

• A relatively normal-appearing fundus except for slight granularity in the foveola.

• Yellow or yellow-white, fleck-like deposits at the level of the RPE, often in a pisciform (fish-tail) configuration.

• Atrophic macular degeneration: May have a bull’s eye appearance as a result of atrophy of the RPE around a normal central core of RPE, a “beaten-metal” appearance, pigment clumping, or marked GA.

NOTE In early stages, vision declines before visible macular changes develop.

Other

Vermilion or light-brown fundus with obscuration of choroidal vasculature. Atrophy of the RPE just outside of the macula or in the midperipheral fundus, normal peripheral visual fields in most cases, and rarely an accompanying cone or rod dystrophy. Peripapillary sparing best seen by FAF. The ERG is typically normal in the early stages but may become abnormal late in the disease. The EOG can be subnormal.

Inheritance

Usually autosomal recessive, but occasionally autosomal dominant (dominant cases may be asymptomatic into middle age).

• Pattern dystrophy: Has peripapillary sparing similar to Stargardt. Autosomal dominant. See  11.31, Best Disease (Vitelliform Macular Dystrophy).

• Fundus albipunctatus: Diffuse, small, white, discrete dots, most prominent in the midperipheral fundus and rarely present in the fovea; congenital stationary night blindness variant; no atrophic macular degeneration or pigmentary changes. Visual acuity and visual fields remain normal. Prolonged dark-adaptation time with normal ERG.

• Retinitis punctata albescens: Similar clinical appearance to fundus albipunctatus, but visual acuity, visual field, and night blindness progressively worsen. A markedly abnormal ERG develops. Variant of RP.

• Drusen: Small, yellow-white spots deep to the retina, sometimes calcified, usually developing later in life. IVFA may be helpful (all drusen exhibit hyperfluorescence, whereas fundus flavimaculatus lesions show variable hyperfluorescence and some areas without flecks show hyperfluorescence).

• Cone dystrophy or CRD: May have normal fundus in early stages. May have bull’s eye maculopathy, but have significant color vision deficit and a characteristic ERG. See 11.29, Cone Dystrophies.

• Batten disease and Spielmeyer–Vogt syndrome: Autosomal recessive lysosomal storage disease characterized by progressive dementia and seizures. May have bull’s eye maculopathy, variable degree of optic atrophy, attenuation of retinal vasculature, and peripheral RPE changes. Shows characteristic curvilinear or fingerprint inclusions on electron microscopy of peripheral blood or conjunctival biopsy. Variants of RP.

• Chloroquine/hydroxychloroquine maculopathy: History of medication use. See 11.32, Chloroquine/Hydroxychloroquine Toxicity.

• Pentosan polysulfate toxicity: Medication used to treat the symptoms of interstitial nephritis.

• PXE can have a pattern dystrophy.

• Nonphysiologic visual loss: Normal ophthalmoscopic examination, IVFA, OCT, ERG, and EOG. Patients can often be tricked into seeing better by special testing. See 10.25, Nonphysiologic Visual Loss.

Indicated when the diagnosis is uncertain or must be confirmed.

1. History: Age at onset, medications, family history?

2. Dilated fundus examination.

3. OCT may show photoreceptor disorganization, outer retinal atrophy, and RPE changes, which may appear early even with a normal fundus examination.

4. IVFA often shows blockage of choroidal fluorescence producing a “silent choroid” or “midnight fundus” as a result of increased lipofuscin in RPE cells.

5. FAF can be helpful in diagnosis and in monitoring disease progression.

6. ERG and EOG.

7. Formal visual field examination (e.g., Octopus, Humphrey).

8. Consider genetic testing: Sequencing of the ABCA4 gene (found to be abnormal in many cases of Stargardt disease and other related maculopathies).

Avoid vitamin A supplementation. Ultraviolet light-blocking glasses when outdoors may be beneficial. Lutein and zeaxanthin supplementation might be helpful. Low-vision aids, services dedicated to helping the visually handicapped, and genetic counseling are helpful. Trials of vitamin A antagonists and gene therapy are ongoing. Safety glasses might be of help since trauma to the retina can cause an inflammatory response to the accumulating lipofuscin.