Elsevier

Ophthalmology

Volume 90, Issue 11, November 1983, Pages 1360-1368
Ophthalmology

Potential Acuity Meter Using a Minute Aerial Pinhole Aperture

https://doi.org/10.1016/S0161-6420(83)34381-5Get rights and content

Abstract

A new instrument allows accurate measurement of retinal visual acuity behind mild to moderate cataracts. Mounted on a slit lamp, the Potential Acuity Meter projects a Snellen visual acuity chart into the eye via a narrow beam of light converging to a minute aerial aperture only 0.15 mm in diameter. The examiner aims the narrow beam through “windows” in the cataract, avoiding blockage or scattering of the light that would otherwise occur. In 47 cataractous eyes having best preoperative visual acuity of 20/200 and better, the postoperative visual acuity was predicted to within three lines in 100% of cases, and to within two lines in 91%. With a successful result from cataract surgery defined as postoperative vision of 20/40 or better, the prediction of success with the Potential Acuity Meter was correct in 95% of cases.

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Cited by (79)

  • Restitution of potential visual acuity in low vision patients with the use of yoke prisms

    2021, Journal of Optometry
    Citation Excerpt :

    One of the most common tools used today in ophthalmology is the potential acuity meter (PAM) which provides estimates of PVA at the macula in the presence of pathology obstructing macular access to incoming light stimuli. The PAM estimates provide a measure of PVA after interventions to remove pathology like cataracts.16 The need to know PVA in cases with LV secondary to maculopathies is similar like in cases without maculopathies in order to plan and assess LVR interventions.

  • Clinician versus potential acuity test predictions of visual outcome after cataract surgery

    2009, Optometry
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    Distance VA was measured at 3.2 m under monocular conditions using an early treatment diabetic retinopathy study (ETDRS) logMAR chart (mean luminance 200 cd/m2), using a by-letter scoring system (0.02 log units per letter) and a termination rule of no letters called correctly on a line.22 The standard Potential Acuity Meter (Mentor Inc., Norwell, Massachusetts) procedure5 was used, and Snellen VA was determined as the smallest line at which the majority of letters were correctly identified. The Rodenstock Retinometer (Rodenstock, London, United Kingdom) was the interferometer used following the standard procedure23 with the gratings presented at 4 random orientations: horizontal, vertical, or oblique (45° to the right or the left).

  • Capabilities of potential vision test measurements. Clinical evaluation in the presence of cataract or macular disease

    2006, Journal of Cataract and Refractive Surgery
    Citation Excerpt :

    Distance VA was measured at 3.2 m under monocular conditions using a Bailey-Lovie logMAR chart (mean luminance 200 cd/m2) using a by-letter scoring system (0.02 log units per letter) and a termination rule of no letters called correctly on a line.40 The standard PAM (Mentor) procedure was used,6,41 and VA was determined as the smallest line at which the majority of letters were correctly identified. The LI (Rodenstock) was measured using the Rodenstock retinometer following the standard procedure,20,25,42 with the gratings presented at 4 random orientations: horizontal, vertical, or oblique (45 degrees to the right), and oblique (45 degrees to the left).

  • Visual Acuity

    2006, Borish's Clinical Refraction
  • Comparison of the potential acuity meter and pinhole tests in predicting postoperative visual acuity after cataract surgery

    2005, Journal of Cataract and Refractive Surgery
    Citation Excerpt :

    The patient was asked to read the letters through a standard pinhole (1.5 mm aperture, Precision Vision). The PAM test (PAM-1000, Mentor) was then given as previously described.1 The patients had phacoemulsification with foldable intraocular lens implantation under topical anesthesia with monitored anesthesia care.

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Presented in part at the Eighty-sixth Annual Meeting of the American Academy of Ophthalmology, Atlanta, Georgia, November 1–6, 1981.

Drs. Minkowski and Guyton have a proprietary interest in the commercial model of the Potential Acuity Meter produced by Mentor O & O, Inc.

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