Hypertensive retinopathy and chorioretinopathy are conditions that affect the retina and choroid of the eye due to chronic high blood pressure or acute hypertensive episodes. Risk factors for hypertensive retinopathy include age, diabetes, smoking, dyslipidemia, and other vascular disorders that can disturb perfusion pressures.1 Hypertensive retinopathy affects 6% to 10% of patients with high blood pressure.
On retinal exam, retinal vessel narrowing, tortuosity, hemorrhages, exudates, and cotton-wool spots are often noted.2 The severity of hypertensive retinopathy is usually correlated with the duration and severity of hypertension and can be graded based on these findings, with higher grades indicating more severe damage to the retina and correlating with worse visual outcomes.3,4
Due to the insidious nature of hypertensive vascular disease, the retina is frequently a sign of end organ damage, and visual changes are often an early presenting symptom.5 This places an extra emphasis on the ophthalmologist to recognize concerning exam findings, correlate life-threatening systemic signs, and respond quickly to limit morbidity and mortality.
Here we discuss the case of a patient in her sixth decade with bilateral visual changes who calmly presented for her ophthalmology appointment in hypertensive crisis.
Case Presentation
A 58-year-old woman presented to the general ophthalmology clinic, reporting sudden onset of decreased vision over the previous week. She also noted a new headache and mild bilateral photophobia. She did not report eye trauma and her past ocular history was unremarkable. She had a medical history notable for obesity, hyperlipidemia, hypertension, chronic kidney disease, rheumatoid arthritis managed well on leflunomide, and Graves’ disease status after radioactive iodine ablation.
Her visual acuity was 20/60 in the right eye and counting fingers at 3 feet in the left eye. Intraocular pressures were normal, visual fields by confrontation were generally full, and pupils were equal and reactive bilaterally. Fundoscopy showed bilateral disc edema, tortuous vessels, sizable cotton wool spots, intraretinal hemorrhages, and hard exudates tracking along the inferior arcades (Figure 1, A and B). On optical coherence tomography (OCT), a large amount of subretinal and intraretinal fluid was noted, extending from the disc and into the macula (Figure 2, A and B).
Given her acute headache and vision loss, in addition to her exam findings of bilateral macular fluid, hemorrhages, exudates, and ischemia, underlying hypertensive pathology was of primary concern. She was urgently referred to the emergency department, and she was found to be in hypertensive crisis with a blood pressure of 222/140 mmHg. She was diagnosed with malignant hypertension and aggressive intravenous antihypertensive management was initiated. Once blood pressure was stabilized, she was started on a long-term oral pharmacological regimen and discharged with instructions to follow up with her primary care doctor and an endocrinologist.
Three weeks later, the patient’s vision had improved to 20/25 in the right eye and 20/40 in the left eye. Fundoscopy showed significant improvement of hemorrhages, smaller exudates, and reduced disc edema (Figure 1, C and D, white arrows). Substantial reduction in subretinal and intraretinal macular fluid was observed on OCT (Figure 2, C and D). Fluorescein angiography showed delayed choroidal flush with stippling and leakage from the optic disc. Close follow-up without ocular intervention was recommended and the patient was encouraged to follow up with both her primary care provider and an endocrinologist. An adrenal mass was later identified, and the patient was diagnosed with primary hyperaldosteronism. Her disease was medically managed, but she ultimately developed end-stage renal disease and passed away ~2 years after initial presentation.
Discussion
The pathophysiology of hypertensive retinopathy/chorioretinopathy is complex and multifactorial, involving a combination of vascular, hemodynamic, and inflammatory mechanisms. First, elevated pressures cause deposition of fibrinoid material and collagen within the walls of the arterioles. This narrows the lumen, increasing the resistance to blood flow, and leads to thickening of the vessels that are appreciated as copper wiring, arteriovenous nicking, and vessel tortuosity on dilated exam.6 Second, this elevated resistance causes damage to the endothelial cells of the vessel lumen, reducing the localized source of nitric oxide. This leads to vasospasm and ischemia, observed as the characteristic cotton wool spots in the nerve fiber layer or Elschnig spots on the RPE from infarction of the choriocapillaris.3,7-9 Third, exposure to the damaged endothelium allows activation and adhesion of leukocytes,10 leading to inflammation and break down of the brain retina barrier.11 This allows plasma to squeeze through widened fenestrations, leading to edema, retinal/subretinal fluid, and exudate.
Grading
The pathological changes of hypertensive retinopathy can, of course, be monitored in vivo directly through dilated retinal exam, allowing the severity of the disease to be tracked over time. There are a number of popular grading systems for hypertensive retinopathy, including the Keith-Wagener-Barker and the Wong and Mitchell classification systems, which rely on systematic description of retinal pathology on the slit lamp without the need for imaging.3,12
The grading of patient disease typically consists of progressive stages, ranging from mild to severe, based on the presence of established features.3 Of specific interest, the Wong and Mitchell classification found that worsening grades of hypertensive retinopathy were strongly correlated with the extent of other systemic pathology,3 suggesting that the retina may be a reasonable reflection of peripheral vascular disease. Mild disease (grade 1 or 2) is characterized by subtle vascular changes such as arteriolar narrowing and arteriovenous nicking. Moderate disease (grade 3) includes 1 or more of the characteristic signs of hypertensive retinopathy, including dot, blot, or flame hemorrhages; cotton wool spots; or hard exudates. Severe stage (grade 4) includes the symptoms of moderate retinopathy with the addition of optic disc swelling.
In practice, current classification systems tend to be more helpful for stratifying patients with mild and moderate disease, rather than severe. For example, the patient in this case presentation is characterized as severe grade due to multiple signs of retinopathy as well as disc edema. Unfortunately, it fails to identify the extent of her retinal disease or macular involvement, suggesting more detailed classification systems may be required for malignant hypertensives.
Presentation and Systemic Symptoms
Malignant hypertension is relatively uncommon, with estimations of new cases thought to be about 1-2 per 100,000 individuals.13 One of the early visual manifestations is decreased visual acuity, which can occur as a result of damage to the blood vessels that supply the macula or RPE. Patients may also experience visual field defects, which can appear as blind spots, peripheral vision loss, or other visual distortions, commonly from peripheral ischemia. As the disease progresses, optic nerve edema, intraretinal/subretinal fluid, and retinal hemorrhages can cause blurring or further visual distortion.
Malignant hypertension also frequently presents with a host of systemic symptoms that can help identify this medical emergency. Symptoms of encephalopathy—such as headache, confusion, and altered metal status—can often occur alongside the visual changes. In addition, peripheral symptoms such as chest pain, problems breathing, claudication, and changes in urine output can reflect the widespread damage that severe hypertension may have on the vessels of the heart, limbs, and kidneys.14
Management and Treatment
The primary goal of treatment for hypertensive retinopathy is to control blood pressure and prevent further damage to the retina and other systemic organs. In malignant hypertension, this is typically achieved in the hospital setting, with intravenous administration of antihypertensive medications such as nitroprusside, labetalol, or nicardipine.14 Once blood pressure has stabilized, patients are switched to an oral regimen following hospital discharge, along with close outpatient follow-up.
In general, outcomes are good, with most patients exhibiting improvement in visual acuity within 2 to 3 months. However, outcomes are largely dependent on the chronicity and severity of the hypertension.
Conclusion
Malignant hypertension is a rapidly progressive and life-threatening form of hypertension which leads to retinal damage, vision loss, and end organ failure. This morbidity and mortality can be avoided through the early detection and treatment of hypertensive spectrum disorders. However, systemic symptoms can be insidious, making identification challenging—especially in patients with minimal interaction with the health care system. As the eye is the only organ system that allows direct visualization of vascular change, the ophthalmologist is often uniquely positioned to identify and prevent the consequences of this disease. This requires that the ophthalmologist incorporates a holistic assessment of the patient, looking beyond the eye. This case emphasizes the continued importance of ophthalmologists in identifying life-threatening primary care issues. NRP
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