Mariko Eura

Effects of head tilt on visual field testing with a head-mounted perimeter imo

Purpose A newly developed head-mounted perimeter termed “imo” enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject’s head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results. Subjects and methods For 20 healthy subjects, we binocularly recorded static OCR (s-OCR) while tilting the subject’s head at an arbitrary angle ranging from 0° to 60° rightward or leftward in 10° increments. By monitoring iris patterns, we evaluated the s-OCR amplitude. We also performed blind spot detection while tilting the subject’s head by an arbitrary angle ranging from 0° to 50° rightward or leftward in 10° increments to calculate the angle by which the blind spot rotates because of head tilt. Results The association between s-OCR amplitude and head-tilt angle showed a sinusoidal relationship. In blind spot detection, the blind spot rotated to the opposite direction of the head tilt, and the association between the rotation angle of the blind spot and the head-tilt angle also showed a sinusoidal relationship. The rotation angle of the blind spot was strongly correlated with the s-OCR amplitude (R2≥0.94, p<0.0001). A head tilt greater than 20° with imo causes interference between adjacent test areas. Conclusions Both the s-OCR amplitude and the rotation angle of the blind spot were correlated with the head-tilt angle by sinusoidal regression. The rotated VF was correlated with the s-OCR amplitude. During perimetry using imo, the change in the subject’s head tilt should be limited to 20°.

Test Conditions in Macular Visual Field Testing in Glaucoma

Purpose: The purpose of this study is to evaluate the suitable visual field (VF) test conditions (target size, test type, and eccentricity) for the macular region, we investigated the correlations between the ganglion cell layer (GCL) thickness and 6 VF test results. Methods: We tested 32 eyes of patients (61.1±9.2 y) with preperimetric (6), early-stage (16), and moderate-stage (10) glaucoma. The VF tests included 3 SAP (the 10-2 HFA using SITA with target size III [HFA SITA (III)], full threshold with size III [HFA FULL (III)] and size I [HFA FULL (I)]) and 3 visual function-specific perimetry tests (the 10-2 SWAP, 10-2 flicker, and 10-2 Humphrey Matrix). The GCL and inner plexiform layer (GCL+IPL) thickness was measured by Spectral Domain Optical Coherence Tomography (SD-OCT) with a macular 7×7 mm2 cube scan (3D OCT-2000, Topcon). The coefficient of determination (r2) for the correlation between visual sensitivity and the GCL+IPL thickness was calculated for each test at eccentricities 0 to 5 degrees, 5 to 7 degrees, and 7 to 10 degrees using linear and quadratic regressions. Results: All 6 tests showed the strongest correlation with the GCL+IPL thickness at 5 to 7 degrees. The respective r2 (linear) and R2 (quadratic) for HFA SITA (III), HFA FULL (III), HFA FULL (I), SWAP, Flicker, and Matrix were (0.40, 0.50), (0.43, 0.53), (0.44, 0.46), (0.51, 0.51), (0.33, 0.34), and (0.52, 0.52). Conclusions: As compared with the frequently-used SAP with a size III, SAP with size I and the function-specific perimetry tests (especially the Matrix) could be more suitable for testing the macular region.

Evaluation of kinetic programs in various automated perimeters

PurposeKinetic programs in four automated perimeters were evaluated and compared for their clinical usefulness using four simulated visual field (VF) patterns.MethodsUsing the results of conventional Goldmann manual kinetic perimetry (MKP), simulated fields with concentric contraction, a temporal residual island only, a small central island with a temporal island, and a ring scotoma were created. Four kinetic programs, Humphrey 750i Kinetic Test (Humphrey), OCULUS Twinfield 2 Kinetic Perimetry (OCULUS), OCTOPUS 900 Goldmann Kinetic Perimetry (OCTOPUS GKP), and Kowa AP-7000 Isopter (Kowa) were tested by the 4 simulated defect patterns using stimuli of V/4e, I/4e, I/3e, I/2e, and I/1e at speeds of 3 and 5°/s.ResultsExcept Humphrey, OCULUS, OCTOPUS GKP, and Kowa could obtain isopters nearly comparable to those of Goldmann MKP. However, their results were considerably influenced by the examiner’s skill. Besides, Humphrey had restrictions on target presentation, and OCULUS and Kowa had problems in isopter drawing and in filling in the scotoma. OCTOPUS GKP was the only method that could correctly detect and depict all four defect patterns. It also had relatively shorter test durations among the three methods excluding Humphrey, which did not have a built-in function for test duration measurement. The perimeters’ test ranges for the periphery were 90° for Humphrey, OCULUS, and OCTOPUS GKP, and 80° for Kowa.ConclusionTo assess kinetic fields with various defect patterns, OCTOPUS GKP seems to be the most useful method.