History of present illness
A 57-year-old male patient presents with progressive blurry vision in both eyes (OU). The onset of his symptoms was gradual, and he mentions that vision was particularly poor during low light conditions, and that this has prevented him from driving at night. The patient reports no difficulty with color vision and endorses no notable personal history of ocular disease.
Ocular examination findings
Visual acuity without correction was 20/20 OU. Intraocular pressure was 17 OU by applanation. Pupils were round, equal, and reactive without a relative afferent pupillary defect in each eye. External and anterior segment examination was unremarkable with trace nuclear sclerotic cataracts. On dilated fundus examination, both optic nerves appeared normal without pallor. The macula was flat without mottling or edema. The vessels appeared normal without attenuation ( Fig. 21.1 ). The retinal periphery showed numerous scattered white spots but no pigmentary alteration ( Fig. 21.2 ).
Questions to ask
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Is there any family history of known retinal dystrophies or ocular disease? Conditions such as ocular albinism, gyrate atrophy, or retinitis pigmentosa often have genetic associations and may commonly be seen in other family members.
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No
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What systemic medications is the patient taking? Certain medications, such as phenothiazines and oral isotretinoin, have been associated with nyctalopia.
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Patient is taking only lisinopril for hypertension.
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What were the onset and duration of the patient’s symptoms? Conditions such as cataracts and glaucoma typically have a slow progression and evolve over several years.
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Patient endorses that symptoms were gradually worsening over the past 6 months.
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Does the patient have a history of bariatric surgery, or does the patient have major dietary restrictions?
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Yes, the patient underwent uncomplicated bariatric surgery for obesity 5 years before presentation.
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Assessment
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This is a 57-year-old male patient with no previous ocular disease, though with a history of bariatric surgery presenting with progressive nyctalopia.
Differential diagnosis
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Retinitis pigmentosa
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Vitamin A deficiency
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Zinc deficiency
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Cataract
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Albinism
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Gyrate atrophy
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Oguchi disease
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Optic atrophy
Working diagnosis
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Vitamin A deficiency
Multimodal testing and results
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Fundus photos
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Color fundus photos show a grossly normal fundus appearance in the posterior pole, but numerous whitish-yellow dots are visualized in the retinal periphery ( Fig. 21.2 ).
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Optical coherence tomography (OCT)
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Normal appearance with intact layers and normal contour through the fovea of both eyes; subretinal hyperreflective material along with an irregular appearance of the interdigitating zone and the ellipsoid zone as is appreciated in the retina periphery where whitish dots are most prominent ( Figs. 21.3 and 21.4 ).
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