Cherry-Red Spot - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Cherry-red is a fundoscopic examination feature. The fundoscopic examination is done using a magnifying glass and a special light to study the fundus of the eyes. The fundus of the eye is the innermost part of the eye, containing the retina and the optic nerve. Cherry-red spot occurs from retinal edema due to various conditions like retinal artery occlusion and traumatic retinal ischemia, where the perimacular part of the retina will remain translucent, and the fovea centralis (the blind spot) will be normal.

In simpler words, the fat accumulates in the retinal ganglion cells, surrounded by the fovea. The retinal ganglion cells will become cloudy and white, while the fovea remains the same, giving a cherry-red spot look. This feature helps in diagnosing various underlying conditions associated with it. In most cases, the cherry-red spot will resolve on its own or diminish over time. But this does not mean that the condition is resolved either.

What Are the Causes and Risk Factors of Cherry-Red Spot?

• Central Retinal Artery Occlusion - The blood vessels supplying the retinal layer get blocked, causing vision loss. This can be caused due to increased blood sugar levels, blood pressure, and glaucoma.

• Intraorbital Hemorrhage - It is caused due to an intraorbital trauma or surgery. This can compromise retinal circulation, causing cherry-red spots.

• Macular Infarction - It is a condition causing vision problems, but the cause is not known. A few suggest ocular trauma to be the cause in some cases.

• Tay-Sachs Disease - It is a genetic disorder characterized by the absence of enzymes essential to break down the fatty content called gangliosides. The gangliosides start accumulating in the brain and ganglion cells of the retina, causing cherry-red spots.

• Niemann-Pick Disease - It is a rare genetic disorder characterized by the body’s inability to metabolize the fats inside the cells.

• Gangliosidosis - This is a name for a group of inherited diseases where the body lacks different proteins to break the fatty substances like gangliosides, resulting in its over-accumulation.

• Sialidosis (genetic disorder).

• Farber’s Disease - It is characterized by the accumulation of lipids in the joints, tissues, and central nervous system. It is an inherited disorder.

• Metachromatic Leukodystrophy - It is characterized by the accumulation of lipids in the cells of the brain, spinal cord, and peripheral nerves.

• Retinitis (inflammation of the retina).

• Retinal Necrosis - It is a necrotizing condition of the retinal layer caused by varicella zoster and herpes simplex virus.

• Subacute Sclerosing Panencephalitis - It is a neurological condition characterized by brain inflammation related to measles infection.

• Drug toxicity was also found to be a major cause. A few examples of the drugs are carbon monoxide, methanol, Quinine, and Dapsone.

• Trauma-induced retinal opacification, avulsion of the optic nerve, and occlusion of the retinal artery are found to cause cherry-red spots.

What Is the Pathophysiology of Cherry-Red Spot?

In storage disorders, such as Tay Sachs, metabolic products accumulate in the retinal ganglion cells and other retinal layers. This accumulation leads the cells to swell and become opaque. In the case of ischemia, the blockage of blood flow results in ischemia of the inner retinal layers. This leads to an edematous retina due to the lack of oxygen and nutrients. The fovea, which is rich in photoreceptors and lacks ganglion cells, retains its transparency and normal appearance because it is less affected by these metabolic accumulations. It creates a vivid red spot against the pale and opaque retina. It comprises retinal transparency in the surrounding areas while sparing the foveal region.

What Are the Signs and Symptoms of Cherry-Red Spot?

The signs and symptoms of cherry-red spot are as follows:

• Patients will experience sudden vision loss for a few seconds.

• Older patients might experience headaches, difficulty chewing, joint aches, and weight loss.

• Transient migraine will be present due to the narrowing of the arteries.

How to Diagnose the Condition Associated With Cherry-Red Spot?

Diagnosing the underlying condition causing cherry-red spots is of utmost importance. A detailed history of the patient and a complete examination is required to narrow the condition causing it.

• Patient History: A complete history of the patient will be noted. The sudden vision loss will be assessed. The present history of cardiovascular diseases will be evaluated. Patients will be asked if a lysosomal storage disorder is present in any of the family members. Patients will be asked about drug usage, smoking, and if they have had any eye injuries.

• Diagnostic Tests: The patient will be asked to undergo a series of diagnostic tests like fluorescein angiography (to assess retinal blood flow), computed tomography (CT), magnetic resonance imaging (MRI), electroretinography (measures electrical responses of various cells in the retina), magnetic resonance angiography (MRA), and blood pressure and pulse monitoring.

• Laboratory Tests: Laboratory tests are also considered to arrive at a diagnosis. These include tests to find the complete blood count and blood sugar levels, blood pressure, cholesterol levels, homocysteine levels, erythrocyte sedimentation rate, C-reactive protein levels, lipid and triglycerides levels, and molecular analysis of the cells or tissues.

What Are the Possible Differential Diagnoses of Cherry-Red Spot?

• Macular hemorrhage.

• Tay-Sachs disease.

• Sandhoff disease (similar to Tay-Sachs disease but with more widespread systemic involvement.

• Central retinal artery occlusion (painless vision loss in one eye).

How to Manage the Cherry-Red Spot and Associated Conditions?

• Medical Treatment: In case of central retinal artery occlusion, doctors will recommend ocular massages; hyperbaric oxygen therapy and medications to decrease the intraocular pressure will be prescribed. In cases of lysosomal storage disorders, doctors will recommend therapy to replace the enzymes, improve symptoms, and reduce the intake of specific molecules.

• Surgical Treatment: Surgical removal of the clot will be suggested. Pars plana vitrectomy is the procedure done to remove the clot. It is a special procedure done by inserting specially designed tools through the sclera (the white part of the eye) and removing the vitreous humor and retina affected by the scar tissue.

What Is the Prognosis?

There is no clear evidence that suggests the above management brings the lost vision back. But, the condition will improve, and the symptoms can be controlled.

What Are the Complications Associated With It?

Neovascularization is a common complication of this condition. Neovascularization can be treated if there is not much delay in seeking a doctor.

Conclusion

The cherry-red spot is a fundoscopic feature and can be associated with various conditions. In this case, diagnosis plays a major part. A precise diagnosis is required to frame the treatment plan. No evidence suggests vision loss can be treated. Only the conditions can be treated to some extent, and the symptoms can be controlled. Seeking a doctor as soon as the first sign occurs will help the doctor manage the condition in a better way.