Clinical evaluation of five portable tonometers.

BACKGROUND: Intraocular pressure (IOP) measurements obtained with five commercially available portable tonometers (Keeler Pulsair 2000, Tomey Pro-Ton, Tono-Pen XL, Perkins, and Shiotz) were compared to IOPs measured with a Goldmann tonometer in order to predict whether instrument accuracy justified substitution of a portable instrument for the Goldmann in all or specific circumstances. METHODS: A total of 31 patients (59 eyes) were assessed. The order of techniques was random except that in each case Goldmann tonometry was performed first and Shiotz tonometry was performed last. Examiners were masked to all other IOP measurements. Correlation and regression analyses were used to predict Goldmann IOP from the other portable tonometer readings. In addition, the difference in pressure readings was compared to mean pressure readings. RESULTS: Comparisons of means, correlations, regression equations, and box plots of difference scores were performed to determine which techniques were more accurate. The results varied slightly depending on the method used. All IOPs obtained with portable tonometers showed significant correlation and regression equations compared to the Goldmann IOPs. The correlation ranged from (r = 0.75) for the Keeler Pulsair to (r = 0.66) for the Schiotz. Three tonometers (Tono-Pen, Schiotz, and the Pro-Ton) showed a small significant underestimation of the Goldmann IOPs. CONCLUSIONS: All portable tonometers were able to accurately predict Goldmann IOPs. While three of the tonometers were found to underestimate Goldmann IOP on average, these results can be corrected by either adding the underestimation or by using the best fitting regression equation.

One-year results of the intrascleral glaucoma implant.

This is an initial report from a study to determine the safety and efficacy of an implant placed within the sclera to relieve elevated intraocular pressure (IOP). It describes the first eight patients to receive the implant. Intraocular pressure and pneumotonometry were evaluated preoperatively and postoperatively for one year. In five patients, IOP decreased. Three patients in which the implant was considered a failure because of wound leaks had patch grafts, removal of the implant, or both. The five successful cases have continued to show reduced IOP.

Comparison of the Farnsworth-Munsell 100-Hue, the Farnsworth D-15, and the L'Anthony D-15 desaturated color tests.

OBJECTIVE: The Farnsworth-Munsell 100-Hue, the Farnsworth D-15, and the L'Anthony D-15 desaturated color tests were administered to patients with glaucoma to determine whether the D-15 or D-15 desaturated color tests could be used to predict performance on the 100-Hue test in clinical populations. METHODS: The three color tests were administered to 35 patients with glaucoma. The results were analyzed using the method of Vingrys and King-Smith that calculates an angle (type of color loss) score, S-index (measure of the randomness of cap arrangement), and a C-index (a measure of the severity of color loss) based on the cap arrangement. RESULTS: The 100-Hue error score was significantly related to the D-15 and D-15 desaturated C-indexes. Furthermore, the 100-Hue S-index could be predicted from the D-15 or D-15 desaturated S-indexes. The 100-Hue angle could not be predicted from the D-15 or D-15 desaturated color tests. CONCLUSIONS: The D-15 desaturated color test (which requires significantly less time to administer) may be used to assess the severity of color vision deficit in some patient populations.

Binocular visual impairment in glaucoma.

Monocular and binocular vision was assessed in patients with glaucoma (n = 21), in patients with ocular hypertension (n = 20), and in age-matched visual control subjects (n = 20) using three tests: color vision with the Lanthony Desaturated D-15 test, low spatial frequency contrast sensitivity with the Pelli-Robson chart, and stereoacuity with the RANDOT test. No significant differences were found among the groups in the severity or type of color vision loss. Monocular contrast sensitivity testing showed considerable overlap among groups but a significant loss of contrast sensitivity in the glaucoma patients relative to ocular hypertensives and control subjects. Binocular testing also showed a significant loss of contrast sensitivity in the glaucoma patients compared with both the ocular hypertensives and the control subjects. Stereoacuity also was significantly impaired in the glaucoma patients. These results indicate that two tests of binocular function, stereoacuity and binocular contrast sensitivity testing, may have utility in identifying early glaucomatous damage.