Frequency doubling technology perimetry for detection of glaucomatous visual field loss: The reply

The use of a visual illusion to detect glaucoma: Frequency doubling technology perimetry.

“…In summary, Frequency Doubling Technology perimetry, using either full threshold or rapid screening tests, has now been shown by many investigators to be an efficient and effective method of screening for glaucoma (Cello et al, 2000;Johnson, Cioffi, & Van Buskirk, 1999a, 1999bJohnson & Samuels, 1997;Kondo, Yamamoto, Sato, Matsubara, & Kitazawa, 1998;Quigley, 1998;Sponsel, Arango, Trigo, & Menash, 1998). Although this technique was primarily intended for detecting glaucoma, subsequent investigations have found that it is also able to detect retinal and neuroophthalmologic disorders as well (Johnson et al, 1998;Nearhing, Wall, & Withrow, 1997).…”

“…Their preliminary findings indicated that contrast thresholds for detecting a frequency doubling stimulus were elevated in patients with glaucomatous visual field loss in comparison with normal observers. We have extended these initial findings to optimize the performance of this test procedure and define its clinical characteristics (Adams, Bullimore, Wall, Fingeret, & Johnson, 1999;Chauhan & Johnson, 1999;Johnson, 1995;Johnson, Cioffi, & Van Buskirk, 1999b;Johnson & Demirel, 1997;Johnson & Samuels, 1997;Johnson, Wall, Fingeret, & Lalle, 1998). However, before any further discussion of the frequency doubling illusion, I will present a brief overview of glaucoma.…”

“…The first stimulus pattern consists of 16 targets (4 per quadrant) whose dimensions are 10 deg by 10 deg, plus a central circular target of 5 deg diameter. Because our initial investigations revealed that a few early glaucomatous visual field defects were missed because they were located beyond the limits of the display in the nasal visual field (Johnson & Samuels, 1997), two additional test locations were added along the nasal horizontal meridian. Both stimulus presentation patterns are shown in Figure 5.4.…”

“…The dB scale is logarithmic, and therefore a 10-dB contrast sensitivity corresponds to a stimulus with 10% contrast, a 20-dB contrast sensitivity corresponds to a stimulus with 1% contrast, and so forth. This test procedure has a sensitivity of better than 92% and a specificity of better than 96% (Cello, Nelson-Quigg, & Johnson, 2000;Johnson & Samuels, 1997). False-positive (response when no stimulus is presented), false-negative (failure to respond to a stimulus of maximum contrast), and fixation loss (response to a stimulus presented to the normal blind spot region) "catch" trials are also presented during the test procedure, every 6 to 10 presentations.…”

Combining Optical Coherence Tomography and Fundus Photography to Improve Glaucoma Screening

“…The general population undergoes several eye examinations during health checkups, such as a visual acuity test, IOP test, perimetry test, and fundus photography test [8][9][10][11][12][13][14]. The visual acuity test is unlikely to be beneficial as a glaucoma screening method for early detection because glaucoma is unlikely to cause vision loss until it reaches terminal stages.…”