Table of Contents
Definition of Preseptal and Orbital Cellulitis
Orbital cellulitis is a term that means the infectious inflammation of the posterior tissue to the orbital septum. Orbital fat, muscles and even bony structures can be involved in orbital cellulitis.
Preseptal cellulitis is different from orbital cellulitis. In preseptal cellulitis, the infected and involved tissues are anterior to the orbital septum.
|Orbital cellulitis||Preseptal cellulitis|
|Include gram positives, gram negatives, anaerobes||Usually GAS or staph|
|Requires broad spectrum antibiotics||Treat with narrow spectrum antibiotics|
|Vision risk||Rarely spreads into eye if treated|
Epidemiology of Preseptal and Orbital Cellulitis
Preseptal cellulitis is a more common condition compared to orbital cellulitis, but the morbidity and complications of orbital cellulitis are more severe. Preseptal and orbital cellulitis are morecommon in children rather than adults. Preseptal cellulitis is more common in the children of age 5- 10 years.
Preseptalcellultis starts superficially whereas orbital cellulitis starts deeper into the septum of the orbit.
A possible predisposing factor is paranasal sinusitis. Patients usually have an extension of their paranasal infection or dental infection. Other possible risk factors include trauma, insect bites and skin infections of the eyelid.
The most common risk factor for orbital cellulitis is similar to preseptal cellulitis, direct extension from infected paranasal sinuses. In orbital cellulitis, however, eye surgery or trauma plays a significant role in predisposition to the condition. Metastatic spread of infection from other areas can also cause either of the conditions.
Pathophysiology of Preseptal and Orbital Cellulitis
Patients can develop preseptal cellulitis due to direct extension of infected paranasal sinusesto tissues anterior to the orbital septum. Spread of the infection in soft tissues such as the skin, subcutaneous fat and eye adnexa is also a common factor in the pathogenesis of preseptal cellulitis.
Certain conditions such as dacryocystitis, sinusitis, and recent trauma or surgery to the eyelid or the eye itself can cause preseptal cellulitis.
On the other hand, orbital cellulitis can result from direct hematogenous spread of causative organisms especially in diabetics or immunocompromised individuals. Patients can also have the condition as a complication of direct extension of an infectious focus from the paranasal sinuses separated by a partition of bone only. In one series, almost all patients with orbital cellulitis had some form of paranasal sinusitis.The infection is severe and extensive.
Patients can also develop the condition as a complication to eye surgery and direct inoculation of the eye with causative organisms. Diabetics and other immunocompromised patients are at risk of orbital cellulitis as a complication to trauma to the eye, orbital bone fractures or to surgery to the eye.Orbital cellulitis can spread to cause cavernous sinus thrombosis, cerebral abscess, and meningitis.
In the past, the most common etiology of orbital and preseptal cellulitis was H. influenzae type b. Since the wide-spread introduction of H. influenzae vaccination, the organism became less likely as a cause of orbital cellulitis.
The most common identified organisms nowadays in children with preseptal cellulitis are streptococcus pneumoniae, streptococcus pyogenes and staphylococcus aureus. Staphylococcus aureus and streptococcus pneumoniae are also commonly identified in cases with orbital cellulitis Patients who develop preseptal cellulitis present to the clinic complaining of a swollen eyelid due to eyelid edema, warmth, redness or discoloration of the eye and the eyelid with or without fever but no protrusion of the eye. Visual examination should reveal normal visual acuity with intact ocular movement and proptosis. Patients On the other hand, those who develop orbital cellulitis are usually unable to move their eyes due to severe pain. Visual acuity might be impaired and eye protrusion is common. Eyelid edema and redness can also be seen in orbital cellulitis similar to preseptal cellulitis.
In both conditions, patients might describe a recent history of an upper respiratory tract infection or sinusitis. History taking is essential to exclude other risk factors such as eye surgery or trauma to the orbit.
|Eyelid swelling, redness, discharge||Yes||Yes|
|Normal pupil response||Yes||Yes|
|Abnormal eye movement||Common||No|
|Pain with eye movements||Usually||No|
Diagnostic Workup for Preseptal and Orbital Cellulitis
As part of the evaluation of the patient presenting with preseptal or orbital cellulitis, a full ophthalmologic examination should be carried out. Visual acuity, pupillary response, determination of the intraocular pressure with tonometry, and ophthalmoscopy should be normal in preseptal cellulitis but might be impaired in orbital cellulitis.
On ophthalmoscopy, patients with orbital cellulitis can have optic nerve edema and posterior segment venous engorgement.
Imaging is also essential in the evaluation of the patient presenting with possible orbital cellulitis. Magnetic resonance imaging (MRI) of the orbit can reveal soft tissue involvement, multiple loculations of the posterior segment of the eye, and signs of endophthalmitis. A computed tomography scan of the orbital bone can show orbital bone fractures, a possible risk factor for orbital cellulitis due to trauma. MRI is more preferred than CT scan if there is cavernous sinus thrombosis.
Possible indications for orbital imaging include young age, significant periorbital edema, presence of fever, severe eye pain on movement, and presence of focal neurological signs. Focal neurological signs are suggestive of spread of the infection to the central nervous system.
Blood Cultures are preferred ideally for the selection of best antibiotic based on the microorganism detected. Lumper puncture can be performed if there is suspicion of meningitis
Treatment of Preseptal and Orbital Cellulitis
Treatment options for preseptal and orbital cellulitis can either be medical or surgical. Medical management of preseptal cellulitis includes the administration of adequate antibiotic therapy to treat the infection and limit its spread.
Patients with mild preseptal cellulitis who are older than one year of age can be treated in an outpatient setting with oral antibiotics. Antibiotics choice should cover the most commonly implicated organisms, namely, staphylococcus aureus, and streptococci.
Patients who have severe preseptal cellulitis or those who do not respond to oral antibiotic therapy should be admitted to the hospital for intravenous antibiotic therapy. Additionally, infants younger than one year of age who present with preseptal cellulitis should be treated in an inpatient setting regardless of the severity of the condition.
Those who develop orbital cellulitis should always be treated in an inpatient setting with intravenous antibiotics. Patients suspected to have methicillin resistant staphylococcus aureus should receive intravenous vancomycin.
Combination therapy with intravenous cefotaxime, metronidazole or clindamycin is usually indicated in cases of orbital cellulitis to cover gram-negative organisms and anaerobes. Intranasal corticosteroids are indicated in cases of chronic sinusitis to facilitate nasal drainage. Treatment of sinusitis in cases of orbital cellulitis was found to provide an improved outcome especially in case of subperiosteal abscesses.
Surgical intervention in preseptal cellulitis is rarely needed and is indicated in the case of following-
- impairment of vision
- Suspicion of Pus formation or presence of foreign body
- Evaluation of orbital or large sub periosteal abscess by imaging
- Failure of antibiotics to resolve the infection.
Patients who develop abscesses might need open drainage of the preseptal abscess. On the other hand, patients with orbital cellulitis are more likely to require surgical intervention to remove foreign bodies, bony fragments in case of orbital trauma, drain abscesses or remove an infected eye globe to avoid extension to other adjacent structures such as the central nervous system.
|Oral antibiotics usually sufficient||Unasyn|
|Ceftriaxone and vancomycin if severe or eye-threatening|
|Cephalexin or clindamycin if allergic||CT scan for abscess|
|Surgery if drainable abscess|
|Nose dops for sinuses (saline, α-agonist)|