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ABSTRACT
Various techniques and devices have been developed to aid in the assessment of potential visual acuity prior to cataract surgery. We report a prospective comparison of two such assessments, one made using a new instrument, the hand-held Heine retinometer (HR) (Heine Instruments, Germany), and the other using the Mentor Guyton-Minkowski potential acuity meter (PAM) (Mentor, Inc, Norwell, Mass). A total of 37 eyes were assessed using both instruments just before cataract surgery. Three eyes were excluded from analysis due to postoperative complications affecting visual acuity that could not have been predicted with either instrument. The falsenegative rate was 44% for the PAM and 32% for the HR. There were no false-positive results with either instrument. Neither instrument was particularly accurate in predicting actual final visual acuity (r^sup 2^ = 0.290 and 0.144 for the PAM and HR, respectively). The HR was deemed easier to use.
Many techniques have been proposed for the assessment of central retinal macular function to predict final visual acuity following cataract surgery. At present, the most commonly used instrument is the Mentor Guyton-Minkowski potential acuity meter (PAM) (Mentor Ine, Norwell, Mass). This device is relatively easy to use, but is somewhat cumbersome and must be mounted on the slit-lamp. Previous studies of the instrument have noted a high percentage of false-negative results, but rare false-positive findings. The Heine retinometer (HR) (Heine Instruments, Germany) is a new prototype instrument for assessing potential visual acuity in cataract patients. It is a hand-held device, approximately the size of an ophthalmoscope (Fig 1) that assesses macular function in cataract patients by projecting a pattern of highcontrast stripes with differing spatial frequencies using a standard illumination bulb and a red filter. As such, it functions much like a laser interferometer, but without the laser and with higher contrast...