West Coast Retina
Case of the Month
Presented by Steven Williams, MD
A 50-year-old Caucasian woman presented with decreased vision in both eyes.
Figures 1A and B: Color fundus photograph of the right and left eye. Picture quality is suboptimal on the right eye, but a yellow spot is visible in each macula. Note the vascular tortuosity present as well.
On examination, best corrected visual acuity was 20/32 in the right eye and 20/50 in the left eye. Intraocular pressures were normal. Anterior segment examination revealed mild nuclear sclerosis but was otherwise unremarkable. Posterior segment examination revealed vascular tortuosity of the veins greater than arteries in both eyes. There was a yellow dot in the center of the fovea in both eyes, with loss of the normal foveal reflex (Figures 1). Fluorescein angiography at presentation demonstrated normal arteriovenous transit of dye without evidence of vascular leakage in either eye. There was a pin-point window defect in the fovea of the left eye corresponding to the yellow spot seen clinically (Figures 2). Six years later, spectral domain OCT demonstrated focal attenuation/loss of the photoreceptor outer segments and RPE in the left eye greater than right eye (Figures 3). Fundus photos at 6 year follow-up demonstrated a persistent yellow dot in the left fovea (Figures 4).
Figures 2A and B: Fluorescein angiogram of the right and left eye. Note a punctate area of hyperfluorescence in the left eye. The right eye appeared normal. No leakage was present.
Figures 3A and B: Spectral Domain OCT of the right and left eye, 6 years after presentation. Focal disruption of the photoreceptor outer segment (ellipsoid zone) is seen in the left eye. There is mild attentuation of the ellipsoid zone in the right eye.
Figures 4A and B: Color fundus photograph montage of the right and left eye, 6 years after presentation. Note the diffuse, predominantly venous, vascular tortuosity. There is a persistent yellow spot in the left eye (see inset).
What is your Diagnosis?
The differential diagnosis for yellow foveal spot associated with outer retinal disruption would include photic maculopathy (e.g. solar retinopathy and laser retinopathy), vitreomacular traction syndrome, macula or lamellar hole, and adult onset foveomacular vitelliform dystrophy, popper usage, juxtafoveal telangiectasis and tamoxifen retinopathy.
The differential diagnosis for generalized retinal vascular tortuosity (arteries and veins) includes retinopathy of prematurity, hyperopia and epiretinal membranes. Predominantly venous tortuosity is characteristic of hyperviscosity syndromes, cardiopulmonary disease, pseudotumor, retinal vein occlusion, fetal alcohol syndrome, diabetic retinopathy, and high altitude retinopathy. Predominantly arterial tortuosity is characteristic of anemia, sickle cell retinopathy, carotid cavernous sinus fistula, Coats’ disease, von Hippel-Lindau disease. There are several less common syndromes that are also associated with vascular tortuosity; including DiGeorge syndrome, Familial Retinal Arteriolar Tortuosity (FRAT), fascioscapulohumeral muscular dystrophy, Fabry’s disease, Wyburn-Mason syndrome, Aarskog syndrome and neurofibromatosis type 1.
Past medical history of our patient was remarkable for DiGeorge syndrome. She had multiple associated chronic medical conditions including developmental delay, schizophrenia, obstructive sleep apnea, right-sided aortic arch, mild pulmonary hypertension, hypothyroidism, hyperlipidemia, secondary hyper-prolactenemia, and sensorineural hearing loss. Although the patient denied sun-gazing, her clinical examination was consistent with solar retinopathy.
Solar retinopathy is a form of photic maculopathy that results from prolonged sun-gazing. This condition is seen in a variety of circumstances including direct sun-gazing by sunbathers, eclipse viewing, malingerers, schizophrenia or other psychiatric illnesses, as well as in persons under the influence of hallucinogenic agents.1,2 Soon after sun exposure, patients typically develop a central scotoma, chromatopsia, metamorphopsia and headache.
There is typically mild to modest decrease in visual acuity, which may recover over several months. The presentation may also be asymmetric and is frequently worse in the dominant eye. Clinically a small yellow-white spot may be apparent in the foveola, surrounded by a faint gray zone. The spot fades over several days, leaving a small reddish spot that can be mistaken for a small, full-thickness macular hole. However, on closer stereoscopic inspection, this apparent hole is restricted to the outer retina and likely represents focal loss of retinal photoreceptors.3 Optical coherence tomography typically demonstrates focal damage to the outer retina with well-demarcated borders.4,5 Findings include juxtafoveal microcystic cavities in the outer retina, interruption of the external limiting membrane and the inner and outer segment junctions, with disorganized material in the vitelliform space.5 Fundus autofluorescence shows hypoautofluorescence surrounded by a relatively hyperautofluorescent ring.5 The area of damage usually persists on OCT and is strongly suggestive of prior photic damage, even in the absence of a reported clinical history of exposure. Flourescein angiography is typically normal however there may be a focal area of late staining in the acute phase (1-2 days) or focal window defect in the subacute (days to weeks) and chronic phases. Experimental models suggest that much of the photochemical damage results in disruption of photoreceptor elements and phagocytosis of the apical RPE melanosomes in milder cases, and permanent photoreceptor loss with depigmentation of the RPE in more severe cases.6 In many cases, much of the damage is reversible and patients generally retain good vision.
DiGeorge syndrome (chromosome 22q11.2 deletion syndrome) occurs in approximately 1:4000 births. The majority of patients have a cardiac anomaly and many patients have mild to moderate immune deficiency. Additional clinical features include developmental delay, psychiatric disorders, hypoparathyroidism, renal anomalies, palatal defects, and hearing loss.7 Characteristic facial features include a bulbous nasal tip, micrognathia, eyelid hooding, and small or cupped ears.3 Ocular features include posterior embryotoxon in 49% of patients, tortuous retinal vessels in 34 – 75% of patients and refractive error.8,9
Take Home Points
• Solar retinopathy can be associated with psychiatric illness.
• Visual prognosis in solar retinopathy is generally good, although clinical findings may persist.
• DiGeorge syndrome is a known cause of benign vascular tortuosity.
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