Abstract
Purpose :
Determine an equation to convert logMAR units acquired in our clinical study to diopters.
Methods :
Diopter value was calculated using ∂D(AGE)=7.081/(1+EXP(0.2031*((AGE-36.2)-0.6109))) developed by Anderson et al [IOVS (2008), 49: 2919-2926]. Data collected from the EV06 study was used to construct XY-scatter plots. GraphPad was then used to determine a best-fit equation to logMAR with age. Subsequently, an equation was then found to calculate diopters as a function of logMAR. iTrace aberrometry measurements were obtained for objective analysis.
Results :
The fitted solidline in Figure 1 using equation logMAR(AGE)= 6.8985*(EXP((-3.5413)*AGE^0.4695))) predicts an equivalent age (closed green circles) with logMAR values. Equation Diopter(logMAR) = (6.898)*(EXP(-3.541*logMAR^0.469)) provides the fitted dotted line shown in Figure 2 to calculate the expected diopter value using the clinical derived logMAR value.
Conclusions :
Figures show logMAR scores changed inversely to accommodative amplitude measured by diopters. A numerical relationship was derived to determine an expected diopter change from the measured EV06 logMAR score results. The equation demonstrates diopter magnitude of change increases from +0.5D (average on DAY-1) to more than +1D in over 50% of the patients with EV06 treatment. Using the logMAR transformation equation demonstrates that the 1.5% EV06 Ophthalmic Formulation significantly (P<0.001) improves diopter response compared to placebo group over the 91-DAY treatment duration.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.