ABSTRACT
PURPOSE: To present a home-based visual field examination method using a PC monitor or virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter, in order to assess the possibility of glaucoma screening through the Internet. MATERIALS AND METHODS: Software implementing a supra-threshold algorithm for the central 24° (52 points) of visual field at three threshold levels: 1) -4 db, 2) -8 db, and 3) -12 db, from the age-expected sensitivity was used for the purpose of testing. The software uses the web camera as a "virtual photometer" in order to detect room luminosity and allows self-testing using a computer monitor or virtual reality glasses using an Android smartphone with a 6-inch display. The software includes an expert system to analyze the visual field image and validate the reliability of the results. It also allows the physician to combine the results from two or more tests into a single test in order to achieve higher statistical accuracy of the final result. A total of ten patients, 20 eyes tested×52 points per eye=1,040 visual field test points, were compared point to point to those obtained using the Humphrey perimeter for the same patients, as they appeared randomly and consecutively at the glaucoma department within hours. RESULTS: Good receiver operating characteristic/area under the curve coefficient was found, ranging from 0.762 to 0.837 (P<0.001). Sensitivity ranged from 0.637 to 0.942, and specificity ranged from 0.735 to 0.497. CONCLUSION: The home-based visual field test exhibits a reasonable receiver operating characteristic curve when compared to the Humphrey perimeter, without the need of specialized equipment. The test may be useful for glaucoma screening.
ABSTRACT
PURPOSE: To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter. MATERIALS AND METHODS: Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey perimeter. RESULTS: High correlation coefficient (r=0.808, P<0.0001) was found between the virtual reality visual field test and the Humphrey perimeter visual field. CONCLUSION: Visual field examination results using virtual reality glasses have a high correlation with the Humphrey perimeter allowing the method to be suitable for probable clinical use.
ABSTRACT
PURPOSE: To present a method of visual field examination using a video projector. Also, we compare our results with those of a Humphrey perimeter, which is accepted as standard in automated perimetry. MATERIALS AND METHODS: Software implementing a full-threshold 4-2-step staircase algorithm for the central 30-2 of the visual field (76 points) has been developed and tested in nine eyes of seven patients using an Epson TW 700 video projector. The results were compared to those obtained from the same patients using the Humphrey perimeter. RESULTS: High correlation between the video projector visual fields and those of the Humphrey perimeter was found. The point-to-point correlation coefficient ranged from 0.75 to 0.90, with P<0.0001 for each eye. CONCLUSION: Visual field examination results using a video projector have high correlation with those of a Humphrey perimeter. The method is possibly suitable for clinical use.
ABSTRACT
PURPOSE: To investigate the anatomic and electrophysiologic changes of the macula and the optic nerve in patients with Parkinson disease (PD) without visual impairment. METHODS: Thirty-two eyes of 16 patients with PD (group A) without visual impairment were tested. Visual acuity was 20/20 or better and visual fields as well as color vision testing results were normal. Also, no retinal lesions were assessed. Patients in group B (40 eyes of 20 patients) were age- and sex-matched control subjects. All study participants underwent a comprehensive ophthalmic examination, multifocal electroretinogram (mfERG) recording, and optical coherence tomography (OCT) scan. Thickness of retinal nerve fiber layer (RNFL) along a 3.4-mm-diameter circle centered on the optic nerve head was evaluated using third-generation OCT. RESULTS: The mean P1-response density amplitude of ring 1 of mfERG was 136.69 nV/deg2 in patients with PD and 294 nV/deg2 in control subjects and the difference was highly significant. On the contrary, these values in ring 2 and 3 did not differ statistically between controls and patients with PD. The mean inferior and temporal RNFL thickness was significantly lower in patients with PD than in control subjects (p<0.0001 and p=0.0045, respectively). CONCLUSIONS: In patients with PD with normal vision, we found a decrease in the electrical activity of the fovea as well as in the thickness of the RNFL. Multifocal electroretinogram and OCT scan objectively detect early subclinical PD-associated visual functional impairment.
