Abstract
Purpose: :
Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are laboratory tests used for monitoring disease processes due to their utility as non-specific markers of inflammation. Not infrequently, systemic inflammatory processes show evidence of anterior segment inflammation. This study aimed to evaluate ESR and CRP values during periods of anterior uveitis to determine if ocular inflammation was sufficient to elevate these laboratory values to levels considered outside the normal range.
Methods: :
A retrospective study was performed by reviewing patient charts with ICD-9 diagnosis codes of anterior uveitis (364.01, 364.02, 364.04, 364.3) seen at University of South Carolina Ophthalmology Specialty Clinics over a two year period. From within this subset, charts were further reviewed to select patients in which there was a recorded ESR or CRP value within seven days of documented anterior uveitis by an attending ophthalmologist or resident within the department. Sixteen patients were found that met these criteria, all of which had ESR values within one week of examination. Five of the sixteen patients also had CRP values documented within one week of examination. Additional data including age, sex, degree of inflammation, etiology of inflammation, and bilaterality were recorded as documented. In cases of bilateral anterior uveitis, the degree of inflammation was determined by the more severe eye. ESR and CRP values were then stratified based on reference range values. ESR was considered within the normal range when ≤ 20 mm/hr for patients of age < 40. For patients of age ≥ 40, the normal reference range was calculated as ≤ Age/2 for males, and ≤ (Age +10)/2 for females. CRP was considered within the normal reference range when < 10 mg/L regardless of age or sex.
Results: :
Sixteen patients were evaluated, two of which had multiple examinations corresponding with laboratory data. ESR and CRP were found to be within the normal reference range in 57% (12/21) and 60% (3/5) of patients, respectively. In patients with laboratory data on the same day as examination, ESR and CRP were within the normal reference range in 55% (6/11) and 67% (2/3), respectively. In patients with at least 2+ cellular reaction documented, ESR was found to be within the normal reference range in 60% (6/10) of patients.
Conclusions: :
While ESR and CRP may be elevated in multiple inflammatory processes, anterior uveitis alone does not appear to be sufficient to yield elevated values beyond the normal reference range. In this study, ESR and CRP were within the normal range in 57% and 60% of patients with anterior uveitis, respectively.