Visual acuity in hypertensive crisis
A sudden and significant increase in blood pressure (when the diastolic reading exceeds 130–140 mm Hg) leads to a hypertensive crisis. This condition is often triggered by psychological or physical overexertion, excess salt and fluid intake, alcohol consumption, or antihypertensive drug withdrawal syndrome.
Against the background of critical BP values, cerebral symptoms develop, accompanied by nausea and vomiting. Deterioration of visual acuity at this moment is an alarming sign of target organ damage. In severe crisis, fundus hemorrhages and papilledema are detected. These ophthalmological complications rank alongside such life-threatening conditions as pulmonary edema (due to acute left ventricular failure) and acute cerebrovascular accident.
Ophthalmic sarcoidosis: involvement of the uveal tract
Vision loss can be the primary complaint in specific inflammatory eye diseases. The main pathology in this case is sarcoid uveitis.
Patients typically describe their symptoms as sudden or gradual visual acuity loss and characteristic "blurring" before the eyes. Such a clinical picture requires mandatory and immediate examination by an ophthalmologist to confirm the diagnosis and prescribe active treatment to prevent irreversible vision loss.
Toxic damage: monitoring during ethambutol therapy
Visual assessment is critically important before starting specific chemotherapy. An example is the drug ethambutol.
Before including this drug in the treatment regimen (for both children under 13 and older patients), an ophthalmological examination is strictly necessary. The main goal is to completely rule out pre-existing eye pathology. Any eye diseases already accompanied by reduced visual acuity are a direct contraindication to prescribing ethambutol according to the official instructions. The level of evidence for this recommendation is C.
Monitoring of visual functions
Clinical evaluation of a patient at risk for ophthalmological complications is based on a thorough history taking. The physician must actively check for:
- Changes in visual acuity.
- Color vision disorders.
- Visual field defects.
To monitor pathological changes, monthly examinations by an ophthalmologist with mandatory fundus evaluation are required. As basic prevention and correction, nutritional deficiencies and hypovitaminosis must be eliminated, and in patients with concomitant diabetes mellitus, strict and careful glycemic control must be ensured.
Class and exam questions
What fundus changes are characteristic of a severe hypertensive crisis?
In severe crisis, fundus hemorrhages occur and papilledema develops.
What is the main manifestation of ophthalmic sarcoidosis?
The main pathology is sarcoid uveitis, which subjectively manifests as decreased visual acuity and "blurring".
Why is it mandatory to consult an ophthalmologist before prescribing ethambutol?
Eye pathology must be ruled out. Any eye disease with decreased visual acuity is an absolute contraindication to taking this drug.
What else to study on this topic
- Pathogenesis of fundus hemorrhages in hypertensive crisis
- Sarcoid uveitis: differential diagnosis
- Features of visual field and color vision assessment
- Impact of glycemic control on the progression of retinal vascular lesions
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