Technical standardisation to measure the ocular surface lipid layer with Meibometer 550

Purpose Evaluation of measuring errors in usage of the meibometer550. Methods Measurements of lipid layer of the ocular surface tear film were done by Meibometer 550. For exact measurement we observed possible disruptions, the calibration, hygienically standards, different sampling, alteration after topical treatment.Before each measurement there must be a calibration by clean lipid -free stripes.We observed the adjustment with two clean stripes by double measurement of each other.Both results must be 0. Hygienically influence is presumed by incorrect handling if objects are touched. Stripes were pressed on objects and measured.Those objects were the table surface, the hand of the observer, the gloves and the disinfectant used.We observed different pressure sampling as pressure may extract more lipids from the lid with touch of the lid and no touch, with pressure and without For the influence of topical treatments we dropped several artificial tears directly on the stripes, watery artificial tears, gels, ointments and drops with lipid portions. Results After double calibration new stripes showed values of nearly 0, elder stripes 10-18 u. Hygienically: in clean tables we measured <28u, even clean hand < 60 u, gloves < 5u. Disinfectant fluids decreased measured lipids from 500 to 100 u. There was a difference in sampling with pressure to samplings without pressure between 50 and 80%. Topical treatments changed different after use of watery drops: 0-15u, lipid spray: change 370 u average, fatty ointments: change of 557u to 751 u. Conclusion It is important to notice the careful handling during measuring the lipid layer with MB 550 to obtain valid measuring data. Commercial interest