Monocular Maddox Phoria Measure
#120004
The Maddox Phoria Measure is used to measure Anisophoria. It is constructed from durable plastic. The large 25mm diameter red Maddox lens is mounted perpendicular to the handle. Inside the handle is a 10 Diopter rotating prism. A small indicator in the periphery of the disc indicates the effective prism power (ranges from 0D to 10D).
Testing Procedure:
When the handle is held vertically, the Maddox rods are horizontal and the patient sees a vertical streak. If the patient fixates on the spot-light with their left eye and looks through the phoria measure with their right eye and the notch is to the nasal side of the zero, then the imbalance is right-exo. If it is to the temporal side of the zero, the imbalance is right-eso. Conversely, if the right eye is fixated on the spot-light and the phoria measure is in front of the left eye, base in indicates left-exo and base out indicates left-eso.
When the handle is held horizontally, the Maddox rods are vertical and the patient sees a horizontal streak. If the patient fixates on the spot-light with their left eye and looks through the phoria measure with their right eye and the notch is below the horizontal, the imbalance is right-hyper. If it is above the horizontal, the imbalance is right-hypo. Conversely, if the right eye is fixated on the spot-light and the phoria measure is in front of the left eye, base down indicates left-hyper and base up indicates left-hypo.
If the total imbalance is greater than 10PD, a hand-held prism is held before the opposite eye and the power is combined with that of the phoria measure to obtain a complete measure.