Establishment of a Standard Technique for Determining Laser Flare Photometry Values during Assessment of Intraocular Inflammation.

PURPOSE

The purposes of this study were to determine whether 2 laser flare photometry (LFP) devices produce similar results using various statistical techniques for determining a single, final LFP value for anterior chamber protein level; to determine whether a traditional technique adequately addresses outlier measurements; and to identify a simpler technique that produces LFP values similar to the traditional technique.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

Patients at a tertiary referral center who have histories of uveitis in 1 or both eyes.

METHODS

Seven LFP measurements were obtained on 200 eyes (100 patients) using Kowa FM-500 and FM-700 laser flare photometers (Kowa Company, Ltd). For each device, the final LFP values were determined using 4 statistical outlier removal techniques on all measurements and by means and medians for all 7 and for the first 5 measurements. The final LFP values by each technique were compared between the devices. Using the FM-700, host- and disease-related factors (age, sex, laterality, uveitis history, uveitis activity, and LFP values) were evaluated for their effects on outliers. Laser flare photometry values by each technique were compared with the LFP value by the traditional technique. Intraclass correlation coefficient (ICC) was used to compare values.

MAIN OUTCOME MEASURES

Laser flare photometry values by various techniques.

RESULTS

The mean age of participants was 49.5 ± 19.1 years; 72% were female. Final LFP values did not vary meaningfully between the 2 devices for any technique (all ICCs: 0.81). With 5 measurements, no subgroup factors influenced the presence of outliers, and no final LFP values varied meaningfully from the final LFP value determined by the traditional technique (ICC: 0.97-1.00).

CONCLUSIONS

The automated mean provided by the FM-700 device based on 5 consecutive measurements may be a suitable final LFP value for use in patient care and clinical research.

FINANCIAL DISCLOSURES

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.