Systemic inflammatory markers differentiate between orbital cellulitis and non-specific orbital inflammation

Area of Science:

• Ophthalmology
• Infectious Diseases
• Immunology

Background:

• Bacterial orbital cellulitis (OC) and diffuse non-specific orbital inflammation (DNSOI) present similar clinical symptoms, making differentiation challenging.
• Accurate diagnosis is crucial for appropriate treatment and management of orbital inflammatory conditions.

Purpose of the Study:

• To evaluate the effectiveness of systemic inflammatory markers, specifically white cell count (WCC) and C-reactive protein (CRP), in differentiating between OC and DNSOI.
• To determine which marker, WCC or CRP, is a more reliable indicator for distinguishing these two orbital conditions.

Main Methods:

• A retrospective study analyzed data from 49 patients diagnosed with OC or DNSOI between 2003 and 2021.
• Systemic inflammatory markers (WCC and CRP) at presentation were compared between the OC and DNSOI groups.
• Receiver operating characteristic (ROC) analysis was performed to assess the sensitivity and specificity of WCC and CRP in differentiating the conditions.

Main Results:

• Mean WCC was significantly higher in OC (14.5 × 10³ /μL) compared to DNSOI (9.27 × 10³ /μL) (P = 0.001).
• Mean CRP levels were markedly elevated in OC (104.4 mg/L) versus DNSOI (10.0 mg/L) (P < 0.001).
• An optimal CRP cut-off of 20.2 mg/L showed 90.9% sensitivity and 90.5% specificity for differentiating OC from DNSOI, with CRP being a more accurate predictor than WCC (P = 0.017).

Conclusions:

• Elevated WCC is suggestive of OC, but a normal WCC cannot rule out or differentiate between OC and DNSOI.
• C-reactive protein (CRP) demonstrates superior accuracy in predicting bacterial orbital cellulitis compared to white cell count.
• CRP levels are a valuable tool for distinguishing between bacterial orbital cellulitis and diffuse non-specific orbital inflammation.