**3. Differential diagnosis**

Some of the differential diagnosis for patients presenting with orbital cellulitis may include, allergic reaction to topical or systemic medication, edema from hypo-proteinemia due to variety of systemic causes, orbital wall infarction and subperiosteal hematoma due to unrec‐ ognized trauma or due to blood coagulation disorders. Differential diagnosis may also include orbital pseudotumor (Figure 2), retinoblastoma, metastatic carcinoma and unilateral or

nent loss of vision to the delay in diagnosis and intervention. Further, there were 9 cases of intracranial orbital abscess extension that required either extended treatment with system‐

Patients with orbital cellulitis may present with signs of eyelid swelling, conjunctival chemosis, diplopia and proptosis which may not be prominent in cases of preseptal cellulitis. [1], [8], [9] These patients may present with corneal infections resulting from exposure keratopathy due to their inability to close their eyes. Many of these patients come with local symptoms in the form of eyelid edema, redness, chemosis, decreased ocular motility and proptosis (Figure 1). Patients having superficial signs of swelling (preseptal cellulitis) should be differentiated from deeper infection resulting in orbital cellulitis, in which case, signs and symptoms resulting from inflammation may be helpful. [9] In particular, external ophthalmoloplegia, proptosis and decreased visual acuity are associated with orbital cellulitis rather than preseptal cellulitis. [8], [9] Temperature greater than 37.5℃ and leukocytosis resulting in fever may be more prominent feature of the pediatric orbital cellulitis. [4], [5] In children, external ophthalmo‐ plegia and proptosis may be the most common features, while decreased visual acuity and chemosis may be less frequent signs in both the pediatric as well as in the adult patients. In cases of the optic nerve involvement, disc edema or neuritis with rapidly progressing atrophy resulting in blindness may occur. Mechanical pressure on the optic nerve and possibly compression of the central retinal and other feeding arteries results in optic nerve atrophy. [10] Also orbital inflammation itself may spread directly into the substance of the optic nerve causing small necrotic areas or abscesses. [2] Compression of the feeding vessels as well as inflammation may result in the infarction of the optic nerve, infarction of the sclera, choroids as well as the retina. Inflammation may result in septic uveitis, iridocyclitis or choroiditis with a cloudiness of the vitreous, including septic pan ophthalmitis. A less common complication of orbital cellulitis is glaucoma that can cause decreased vision, reduced visual field or even enlarged blind spot on presentation. On occasion, one may not find any fundus abnormalities. Among our patients presenting to a tertiary eye care center in the developing country, presenting signs of 218 patients with orbital cellulitis included, eyelid swelling in 71.5%, proptosis in 68.3%, motility restriction in 59.2%, pain in 52.3%, and decreased visual acuity in

Some of the differential diagnosis for patients presenting with orbital cellulitis may include, allergic reaction to topical or systemic medication, edema from hypo-proteinemia due to variety of systemic causes, orbital wall infarction and subperiosteal hematoma due to unrec‐ ognized trauma or due to blood coagulation disorders. Differential diagnosis may also include orbital pseudotumor (Figure 2), retinoblastoma, metastatic carcinoma and unilateral or

ic antibiotics alone or in combination with neurosurgical intervention. [3]

**2. Patient presentation**

124 Common Eye Infections

14.2% of cases. [8]

**3. Differential diagnosis**

**Figure 1.** A child with left sided eyelid erythema, swelling and proptosis following a bout of upper respiratory infec‐ tion.

bilateral exophthalmos secondary to thyroid related orbitopathy. [11] In all cases, careful history, thorough physical examination along with carefully selected imaging studies may help in differentiating orbital cellulitis from other causes of proptosis.

**Figure 2.** A 25-year-old male with bilateral eyelid swelling, proptosis and painful diplopia was found to have evidence of bilateral orbital pseudotumor and treated with systemic corticosteroids after imaging studies failed to show evi‐ dence of any infectious cause of his symptoms.
