Sachiko Okuyama

Correlations between M-CHARTS and PHP Findings and Subjective Perception of Metamorphopsia in Patients with Macular Diseases

PURPOSE To assess the correlations between a patients subjective perception of metamorphopsia and the clinical measurements of metamorphopsia by M-CHARTS and PreView PHP (PHP). METHODS The authors designed a 10-item questionnaire focusing on the symptoms of metamorphopsia and verified its validity with a Rasch analysis. M-CHARTS measured the minimum visual angle of a dotted line needed to detect metamorphopsia, and PHP used the hyperacuity function for detection. Subjects were 39 patients with idiopathic epiretinal membrane (ERM), 22 patients with idiopathic macular hole (M-hole), 19 patients with age-related macular degeneration (AMD), and 51 healthy controls. RESULTS Rasch analysis suggested the elimination of one question. The nine-item questionnaire score significantly correlated to the M-CHARTS score in ERM (r = 0.59; P = 0.0004) but not in M-hole and to the PHP result in AMD (r = -0.29; P = 0.04) but not in ERM. Eighty percent of ERM patients with greater horizontal M-CHARTS score subjectively perceived horizontal metamorphopsia more often. M-CHARTS showed better sensitivities than PHP in both ERM (89% vs. 42%) and AMD (74% vs. 68%) and better specificity (100% vs. 71%) in healthy controls. Rasch analysis indicated that the present form of the questionnaire is better suited for moderate to severe cases of metamorphopsia than for mild cases. CONCLUSIONS The questionnaire appears to be a valid assessment of patient subjective perception of metamorphopsia and can be used to supplement the clinical measurements of metamorphopsia by M-CHARTS and PHP in patients with macular diseases.

Detectability of glaucomatous changes using SAP, FDT, flicker perimetry, and OCT.

PurposeTo compare the detectability between glaucomatous visual field changes using standard automated perimetry (SAP), frequency doubling technology (FDT), short-wavelength automated perimetry (SWAP), and flicker perimetry and structural changes using optical coherence tomography (OCT). ParticipantsFifty-nine eyes of fifty-nine patients with open-angle glaucoma, 24 eyes of 24 glaucoma suspects (GSs), and 40 eyes of 40 healthy age-matched subjects. MethodsAll subjects underwent Humphrey visual field analyzer II 24-2 full threshold (SAP), Swedish interactive threshold algorithm-SWAP, FDT (30-1, 30-5, 24-2-1, 24-2-5), flicker perimetry on Octopus 311 (4-zone probability 38S), and Stratus OCT [fast retinal nerve fiber layer thickness (NFLT) and fast optic disc]. To evaluate the visual field, FDT and flicker used the number of abnormal points, whereas SAP used mean deviation (MD) and SWAP used both the number of abnormal points and MD. The areas under the receiver operating characteristic curves [area under the curve (AUCs)] and sensitivities at fixed specificities were used to assess the detectability of glaucoma. ResultsThe AUC for FDT 30-1, 30-5, 24-2-1, 24-2-5, flicker perimetry, SWAP (MD), and SWAP (number of abnormal points) were 0.95, 0.94, 0.88, 0.89, 0.99, 0.88, and 0.88 in the early glaucoma group and 0.67, 0.69, 0.65, 0.70, 0.80, 0.64, and 0.66 in the GS group, respectively. In the early glaucoma and GS groups, all OCT parameters had an AUC >0.81 except the disc area parameter. Especially, average NFLT had the highest AUC of 0.94 in the OCT parameters. ConclusionsFDT, SWAP, flicker perimetry, and OCT are all useful methods for discriminating between healthy eyes and eyes with early glaucoma. Among all 10 OCT parameters, NFLT has the highest sensitivity for detecting early glaucomatous changes in GS patients.

Quantification of changes in metamorphopsia and retinal contraction in eyes with spontaneous separation of idiopathic epiretinal membrane.

BackgroundTo quantify changes in metamorphopsia and retinal contraction in eyes with idiopathic epiretinal membrane (ERM) before and after a spontaneous separation of ERM.MethodsAmong 92 eyes of 92 patients with idiopathic ERM who were followed up at our hospital, 5 eyes of 5 patients had experienced a spontaneous separation of ERM during the follow-up period. Patient’s metamorphopsia was assessed horizontally and vertically by a metamorphopsia chart developed by our group, M-CHARTS, to obtain the horizontal (MH) and vertical (MV) metamorphopsia scores. Difference in the scores before and after the membrane separation represents change in patient’s metamorphopsia. Changes in retinal contraction were also evaluated horizontally and vertically with our original software for fundus image analysis. The difference between M-CHARTS scores and distances of retinal vessel movements with before and after membrane separation were measured.ResultsAll five subjects showed a decrease in the retinal contraction. Improved visual acuity was observed in three subjects, and no change was seen in the other two. Four subjects obtained better metamorphopsia scores after the membrane separation, while the other one was not detected with metamorphopsia by M-CHARTS either before or after the separation. In subjects with an improved MV, horizontal retinal movement was seen larger than the vertical movement. Similarly, the subjects with an improved MH indicated a larger vertical retinal movement than the horizontal movement.ConclusionsThe direction of patient’s metamorphopsia closely associated with the direction of retinal contraction before and after a spontaneous separation of ERM.

Visual Field Testing with Head-Mounted Perimeter 'imo'.

Purpose We developed a new portable head-mounted perimeter, “imo”, which performs visual field (VF) testing under flexible conditions without a dark room. Besides the monocular eye test, imo can present a test target randomly to either eye without occlusion (a binocular random single eye test). The performance of imo was evaluated. Methods Using full HD transmissive LCD and high intensity LED backlights, imo can display a test target under the same test conditions as the Humphrey Field Analyzer (HFA). The monocular and binocular random single eye tests by imo and the HFA test were performed on 40 eyes of 20 subjects with glaucoma. VF sensitivity results by the monocular and binocular random single eye tests were compared, and these test results were further compared to those by the HFA. The subjects were asked whether they noticed which eye was being tested during the test. Results The mean sensitivity (MS) obtained with the HFA highly correlated with the MS by the imo monocular test (R: r = 0.96, L: r = 0.94, P < 0.001) and the binocular random single eye test (R: r = 0.97, L: r = 0.98, P < 0.001). The MS values by the monocular and binocular random single eye tests also highly correlated (R: r = 0.96, L: r = 0.95, P < 0.001). No subject could detect which eye was being tested during the examination. Conclusions The perimeter imo can obtain VF sensitivity highly compatible to that by the standard automated perimeter. The binocular random single eye test provides a non-occlusion test condition without the examinee being aware of the tested eye.

Intravitreal bevacizumab injection and carotid artery stent replacement for neovascular glaucoma in internal carotid artery occlusion

Neovascular glaucoma (NVG) secondary to internal carotid artery (ICA) occlusion is usually resistant to treatment. We report a case of NVG with ICA occlusion improved by intravitreal bevacizumab (IVB) injection and carotid artery stent replacement (CAS), even though we did not perform panretinal photocoagulation. A 67-year-old male with NVG noted visual loss in his left eye. Magnetic resonance angiography showed left ICA occlusion. He was diagnosed with NVG secondary to ICA occlusion. The next day, we carried out IVB injection in his left eye, following which the iris and angle neovascularization regressed, and the intraocular pressure decreased to normal within a day after the injection. CAS was performed on his left ICA at a month post injection. Two months later, we reinjected bevacizumab in his left eye. His condition remained stable with no recurrence over two years. This case indicates that IVB injection and CAS are useful for early-stage NVG secondary to ICA occlusion.

Detectability of Visual Field Defects in Glaucoma With High-resolution Perimetry.

Purpose:To extrapolate the optimal test point resolution for assessment of glaucomatous visual field (VF) defects including subtle functional defects, we performed high-resolution perimetry with the 0.5 degrees test point resolution. Subjects and Methods:Subjects were 11 eyes of 11 normal volunteers and 16 eyes of 16 glaucomatous patients. Octopus 900 custom test was used to measure 61 points with the test point resolution of 0.5 degrees on the temporal meridian of 45 degrees within the eccentricity of 30 degrees. In the glaucoma cases, VF profiles were extracted in 17 patterns of the test point resolutions that ranged from 0.5 to 8.5 degrees and the mean defect (MD), square root of loss variance (sLV), and maximum sensitivity loss (Max loss) were calculated. The influence of the test point resolution on MD, sLV, and Max loss was examined. In addition, the test range from the fixation point to the eccentricity of 30 degrees was divided into 3 zones. Similarly, each zone was investigated if the test point resolution exerted influence on the MD, sLV, and Max loss. Results:Our glaucoma cases did not show any significant differences in MD and sLV regardless of the resolution. Max loss showed significant difference at resolution ≥1.0 degree. MD and sLV did not show significant differences by the change of resolution in each zone. Max loss showed significant differences at resolution ≥1.5 degrees within the central 10 degrees. Conclusions:To detect subtle VF defects within the eccentricity of 10 degrees, high-resolution perimetry with the test point resolution of <1.5 degrees is necessary.

The interpretation of results of 10-2 visual fields should consider individual variability in the position of the optic disc and temporal raphe

Aims To clarify the anatomical relation between the optic disc and temporal raphe and to examine how these are related to test points in the 10-2 visual field test pattern. Subjects and methods For 22 eyes of volunteers with normal vision (+0.75 D spherical equivalent 7.88 D), a volume scan was used to obtain en-face images from a plane fitted to the inner limiting membrane using optical coherence tomography (OCT). The clearest en-face retinal nerve fibre (RNF) image was chosen for each subject and superimposed on fundus photographs using blood vessels for alignment. Individual landmarks (disc, fovea and visual field blind spot) were then used to superimpose the Humphrey Field Analyzer 10-2 visual field on the OCT image to compare with the RNF image. Results The average disc–fovea–raphe angle was 169.4°±3.2°. Both the disc and temporal raphe were located above the horizontal midline (ie, were inferior in visual field space). For the 10-2 test pattern superimposed on the OCT image, in 54.5% of eyes, the temporal inferior test points adjacent to the horizontal midline mapped to the anatomical inferior hemifield. In 22.7% of eyes, nasal inferior test points adjacent to the horizontal midline mapped to the anatomical inferior hemifield. This mapping is opposite to typically assumed. Conclusion The position of the disc and raphe affects the mapping between structure and function with respect to superior and inferior hemifields. Individual differences in the position of the temporal raphe should be considered when mapping between structure and function for the 10-2 test pattern.

Exploring Test–Retest Variability Using High-Resolution Perimetry

Purpose Test–retest variability (TRV) of visual field (VF) data seriously degrades our capacity to recognize true VF progression. We conducted repeated high-resolution perimetry with a test interval of 0.5° to investigate the sources of TRV. In particular, we examined whether the spatial variance of the observed sensitivity changes or if their absolute magnitude was of more importance. Methods Sixteen eyes of 16 glaucoma patients were each tested three times at 61 VF locations along the superior-temporal 45° meridian using a modified protocol of the Octopus 900 perimeter. TRV was quantified as the standard deviation of the repeats at each point (retest-SD). We also computed the mean sensitivity at each point (retest-MS) and the running spatial-SD along the tested meridian. Multiple regression models investigated whether any of those variables (and also age, sex, and VF eccentricity) were significant independent determinants of TRV. Results The main independent determinants of TRV were the retest-MS at −0.04 dB TRV/dB loss (P < 0.0001, t-statistic 5.05), and the retest-SD at 0.47 dB spatial variance/dB loss (P < 0.0001, t-statistic 12.5). Conclusions The larger effect for the spatial-SD suggested that it was perhaps a stronger determinant of TRV than scotoma depth per se. This might support the hypothesis that interactions between small perimetric stimuli, rapidly varying sensitivity across the field, and normal fixational jitter are strong determinants of TRV. Translational Relevance Our study indicates that methods that might reduce the effects of jagged sensitivity changes, such as increasing stimulus size or better gaze tracking, could reduce TRV.

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.