Correlation of Clinical Aqueous Flare Grade to Semi-automated Flare Assessment using Laser Flare Meter

Abstract

Purpose : To correlate aqueous flare values obtained using laser flare meter with clinical aqueous flare grading using standardization of uveitis nomenclature (SUN) grading scale.

Methods : Patients with clinical diagnosis of anterior, intermediate, posterior, and pan-uveitis were enrolled from a uveitis clinic at a tertiary hospital. All patients initially underwent a dilated ophthalmological examination where clinician’s assessment of aqueous flare using SUN grading scale was recorded. Subsequently, a masked operator performed aqueous flare measurements (≥5) on patients using laser flare meter (Kowa FM-700). Mean aqueous flare measurement values (±SD) as assessed by laser flare meter corresponding to the clinician’s assessment of aqueous flare were correlated. Additionally, we modified the aqueous flare grading by adding additional grading steps (0.5+ and 1.5+) to the current SUN aqueous flare grading scale and correlated with the corresponding laser flare meter measurements.

Results : Two hundred and twenty-nine (229) aqueous flare measurements (108 subjects) were analyzed for this prospective study. 45 females (58.33%); mean age 50.30 ± 15.32 years. Of these measurements, 89 were clinically assessed as no flare, 112 as 1+ flare, and 28 as 2+ flare (SUN Grade). The mean (±SE) aqueous flare measurement values for the clinical grades of the aqueous flare were 5.00 (±1.38), 11.42 (±7.50), and 30.54 (±23.22) photon counts/millisecond for no flare, 1+ flare, and 2+ flare, respectively (Figure 1). The differences among the mean aqueous flare values for clinically assigned SUN aqueous flare grades were deemed statistically significant (p<0.0001). The mean values of the aqueous flare measurements for the modified grading scale are shown in Figure 2. There were significant differences between the mean aqueous flare values when comparing no flare to 0.5+ flare and 1+ flare to 1.5+ flare (p<0.0001).

Conclusions : Laser flare meter provides reliable quantitative assessments of aqueous flare that correlate with the clinician’s assessment. Our results also suggest that adding grading steps of 0.5+ and 1.5+ to the current SUN grading may allow finer differentiation of aqueous flare.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Figure 1. Mean aqueous flare measurement values using SUN grading scale and clinician’s assessment of aqueous flare

 

Figure 2. Mean aqueous flare measurement values using modified grading scale and clinician’s assessment of aqueous flare