Orbital cellulitis

Orbital cellulitis is a serious condition characterised by inflammation and infection of the tissues surrounding the eye. Often arising from bacterial or fungal infections, this condition poses significant risks to vision and systemic health if left untreated. Orbital cellulitis primarily affects the soft tissues within the eye socket, known as the orbit, and can quickly escalate into a medical emergency.

This condition typically develops as a complication of sinusitis, trauma to the eye or surrounding areas, or from the spread of infection from nearby structures. Orbital cellulitis demands prompt recognition and appropriate management to prevent severe complications such as vision loss, intracranial extension of infection, or even life-threatening consequences.

Understanding the pathophysiology, clinical presentation, diagnostic approach, and management strategies of orbital cellulitis is essential for healthcare professionals to provide timely and effective care.

Symptoms

Prompt recognition of its symptoms is paramount for timely intervention and prevention of severe complications.

Early Signs and Symptoms

• Periorbital Swelling: One of the earliest and most common symptoms of orbital cellulitis is swelling around the eye. This swelling often starts in the eyelids but can rapidly progress to involve the surrounding tissues of the eye socket.
• Eyelid Edema: Patients may experience swelling and puffiness of the eyelids, which can be accompanied by redness and warmth in the affected area.
• Pain and Tenderness: Orbital cellulitis typically presents with pain or discomfort around the affected eye. This pain may worsen with eye movement or palpation of the area and can be described as a deep, throbbing sensation.

Ocular Symptoms

• Proptosis: As the infection progresses, patients may develop proptosis, a protrusion of the eye from the socket. This can result from the accumulation of pus or inflammation within the orbit.
• Decreased Visual Acuity: Vision may be affected in orbital cellulitis due to compression of the optic nerve or involvement of surrounding structures. Patients may report blurred vision, double vision (diplopia), or even vision loss in severe cases.
• Restricted Eye Movement: Limited movement of the affected eye, known as ophthalmoplegia, can occur due to inflammation and swelling of the extra-ocular muscles. This can manifest as difficulty in looking in certain directions or complete paralysis of eye movements.

Systemic Symptoms

• Fever and Malaise: In more severe cases, patients may present with systemic symptoms such as fever, chills, and generalized malaise. These systemic signs indicate a systemic inflammatory response to the infection and may accompany more advanced stages of orbital cellulitis.

Complications

• Intracranial Extension: Without prompt treatment, orbital cellulitis can lead to the spread of infection into the brain or surrounding structures, resulting in potentially life-threatening complications such as meningitis or brain abscess.
• Optic Nerve Compromise: Compression or damage to the optic nerve can lead to permanent vision loss if not addressed promptly. Patients may experience visual field defects or complete loss of vision in severe cases.

Causes

Orbital cellulitis is a serious condition arises from various infectious agents gaining entry into the orbit, leading to a cascade of inflammatory responses. Understanding the diverse array of causes contributing to orbital cellulitis is crucial for effective management and prevention of this potentially sight-threatening condition.

Sinusitis

• Bacterial Sinus Infections: The most common underlying cause of orbital cellulitis is bacterial sinusitis, particularly involving the ethmoid sinuses. Infections in these sinuses can spread through direct extension into the orbit via the thin bony walls separating the sinuses from the orbit.
• Ethmoid Sinusitis: The close anatomical proximity of the ethmoid sinuses to the orbit predisposes them to direct extension of infection, resulting in orbital cellulitis. The thin lamina papyracea separating the ethmoid sinuses from the orbit facilitates the spread of pathogens.

Trauma

• Penetrating Trauma: Direct trauma to the orbit or periorbital region, such as lacerations or fractures, can provide a portal of entry for infectious agents. Contaminated foreign bodies or debris introduced into the orbit can serve as a nidus for infection, leading to orbital cellulitis.
• Blunt Trauma: Blunt trauma can cause disruption of the orbital tissues, leading to hematoma formation or disruption of the vascular supply. This compromised tissue integrity creates an environment conducive to infection and subsequent cellulitis.

Spread from Adjacent Structures

• Dental Infections: Infections originating from the teeth or adjacent maxillary sinuses can spread to the orbit via direct extension or through the blood vessels and lymphatic channels. Poorly managed dental infections can serve as a potential source of orbital cellulitis.
• Skin and Soft Tissue Infections: Cutaneous infections, such as cellulitis or abscesses involving the periorbital region, can progress to orbital cellulitis if left untreated. The contiguous spread of infection from the skin or soft tissues to the orbit is a recognised pathway for orbital cellulitis development.

Complications of Ocular Surgery

• Postoperative Infections: Orbital cellulitis can develop as a complication of ocular surgeries, particularly those involving the eyelids, orbit, or adjacent structures. Surgical procedures such as dacryocystorhinostomy or orbital decompression carry a risk of postoperative infections leading to orbital cellulitis.

Hematogenous Spread

• Bacteremia: Systemic bacterial infections can lead to hematogenous dissemination of pathogens, resulting in seeding of the orbit and subsequent development of orbital cellulitis. Conditions such as bacterial endocarditis or septicemia pose a risk for hematogenous spread of infection.

Treatments

Orbital cellulitis poses a significant clinical challenge due to its potential for vision-threatening complications and systemic spread. Prompt and effective treatment is essential to prevent sequelae such as vision loss, intracranial extension of infection, and even mortality.

Medical Management

• Antibiotic Therapy: Prompt initiation of broad-spectrum antibiotics is the cornerstone of medical management for orbital cellulitis. Empiric therapy should cover common pathogens, including Streptococcus pneumoniae, Staphylococcus aureus, and anaerobic bacteria. Intravenous administration is often required initially, with transition to oral antibiotics based on clinical improvement.
• Adjunctive Therapy: In cases of suspected or confirmed fungal orbital cellulitis, antifungal agents such as amphotericin B or voriconazole may be necessary. Antiviral agents may also be considered in cases of viral etiology or herpetic infections.
• Systemic Support: Symptomatic management of associated systemic symptoms, such as fever and pain, is essential. Hydration and monitoring for signs of systemic complications, such as sepsis or meningitis, are critical components of medical care.

Surgical Interventions

• Sinus Surgery: In cases where orbital cellulitis arises from sinusitis, surgical drainage of the involved sinuses may be necessary to facilitate resolution of infection. Functional endoscopic sinus surgery (FESS) or sinus puncture procedures may be performed in conjunction with medical therapy.
• Abscess Drainage: In the presence of orbital abscess formation, surgical drainage may be indicated to evacuate purulent material and relieve orbital pressure. This procedure is typically performed in conjunction with antibiotic therapy and may require ophthalmologic consultation.
• Decompression Surgery: Severe cases of orbital cellulitis with significant proptosis and optic nerve compromise may necessitate orbital decompression surgery. This procedure aims to reduce intraorbital pressure and preserve vision by creating additional space within the orbit.

Supportive Care

• Pain Management: Analgesics may be prescribed to alleviate discomfort associated with orbital cellulitis. Nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids may be used cautiously, taking into account the patient’s overall clinical status.
• Ophthalmologic Monitoring: Close monitoring of visual acuity, pupillary response, and extraocular movements is essential to assess the progression of orbital cellulitis and detect any signs of optic nerve compromise or worsening vision.
• Nutritional Support: Patients with severe orbital cellulitis or those requiring surgical intervention may benefit from nutritional support to optimize healing and recovery.