Results and repeatability of retinal thickness measurements from certification submissions.

Objectives: To present the results for subgroups defined by center point (CP) measurement and to assess the repeatability of the Fast Retinal Thickness Map analysis results from the Stratus OCT3 machine.

Methods: Two hundred eighty-one replicate OCT3 scans from 134 operators' certification submissions to a reading center were analyzed, including scans from eyes that were reported to be normal and eyes with exudative age-related macular degeneration and with macular edema due to diabetic retinopathy or retinal vascular occlusion.

Results: The mean (SD) of the CP was 284 (150) microm and the center subfield (CC) was 301 (130) microm. The CP coefficient of repeatability (CR) was 49 microm and the CC CR was 27 microm. The CR increased by increasing retinal thickness for the CP and the CC within arbitrarily defined subgroups. For the 87 eyes with a session 1 CP of 175 microm or less, the CP CR was 17 microm and the CC CR was 10 microm.

Conclusions: Among experienced operators, given the same operator, machine, and eye at the same sitting, OCT3 retinal thickness maps appear to have a CR that is likely to be less than the clinically important difference.