Factors affecting the total occlusion time in eyes with hyperopic anisometropic amblyopia.

BACKGROUND: Amblyopia treatment by occluding the healthy eye is known to be effective during a sensitive critical period. This study aims to clarify the factors for the total occlusion time (TOT) required for the amblyopic eye to achieve a normal visual acuity (VA) level of 1.0 (0.0 logMAR equivalent). This could contribute to an efficient treatment plan for eyes with hyperopic anisometropic amblyopia. METHODS: Subjects were 58 patients (26 boys and 32 girls; age range, 3.6-9.2, average, 5.8 ± 1.3 years) with hyperopic anisometropic amblyopia. All the subjects had initially visited and completed occlusion therapy with improved VA of 1.0 or better in the amblyopic eye at Kindai University Hospital between January 2007 and March 2017. Using the subjects' medical records, we retrospectively investigated five factors for the TOT: the age at treatment, the initial VA of the amblyopic eye, refraction of the amblyopic eye, anisometropic disparity, and the presence of microstrabismus. Patient's VA improvement at one month after treatment was also evaluated to confirm the effect of the occlusion therapy. RESULTS: The initial VA of the amblyopic eye ranged from 0.1 to 0.9 (median, 0.4). The TOT ranged from 140 to 1795 (median, 598) hours with an average daily occlusion time of 7 hours. The initial VA of the amblyopic eye and presence of microstrabismus were the significant factors for the TOT (p < 0.01). To achieve VA of 1.0 or better, patients with an initial VA of ≤ 0.3 in the amblyopic eye required a longer TOT. Moreover, patients with concomitant microstrabismus required a 1.7-fold longer TOT compared to those without microstrabismus. CONCLUSION: Longer daily occlusion hours and early start of the treatment will be necessary for patients with poor initial VA or microstrabismus to complete occlusion therapy within the sensitive critical period.

Fundus autofluorescence, optical coherence tomography and electroretinography abnormalities in a patient with digoxin retinopathy that resemble those in KCNV2-associated retinopathy.

BACKGROUND: Digoxin related retinal toxicity causes blurred vision, photophobia, central scotoma, color vision abnormality, and electroretinography (ERG) abnormalities. Here, we report a case with transient abnormalities in vison, in which fundus autofluorescence (FAF), optical coherence tomography (OCT), and ERG findings resembled those in KCNV2 (potassium voltage-gated channel modifier subfamily V member 2)-associated retinopathy. CASE REPORT: An 89-year-old woman presented with complaints of acute blurred vision, nyctalopia, photophobia, and color vision abnormality. She received digoxin for tachycardia induced by atrial fibrillation for a month. The fundi showed a faint white ring at the fovea, which showed hyperfluorescence in FAF. OCT showed a thickened EZ in the macula. A dark-adapted (DA)-30 ERG showed a reduced and "squaring (trough-flattened)" a-wave, and a delayed, supernormal b-wave, resulting in a high b/a-wave amplitude ratio. The digoxin dose was reduced following an elevation in serum levels. Five weeks later, her visual acuities improved, and abnormal hyperfluorescence on FAF disappeared. After 6 months, no visual symptoms were reported. The ellipsoid-zone thickening in OCT improved; however, the b/a-wave amplitude ratio on DA-30 ERG remained high. The b-wave in LA-long-flash ERG was initially reduced, which improved after correction of serum level of digoxin. CONCLUSIONS: The patient's clinical findings resembled those of patients with KCNV2-associated retinopathy or temporal hyperkalemia. These disorders appear to have a common pathogenesis, which may be related to abnormal extracellular potassium levels in the retina. The on-bipolar cells seemed to be more affected than the off-bipolar cells in digoxin related retinal toxicity.

The Association Between Improvement of Stereoacuity and Suppression in the Treatment of Anisometropic Amblyopia.

Purpose: To investigate the association between stereoacuity and suppression during occlusion therapy for patients with anisometropic amblyopia. Design: Retrospective study. Patients and Methods: This study included 19 patients with hyperopic anisometropic amblyopia who underwent occlusion therapy. The mean age of the patients was 5.5 ± 1.4 years. The participants were evaluated for improvement in stereoacuity and suppression before beginning occlusion therapy, when the highest amblyopic visual acuity (VA) was achieved, during tapering, at the end of occlusion therapy, and at the final visit. Stereoacuity was evaluated using the TNO test or JACO stereo test. The presence of suppression was evaluated using circle No. 1 of the Stereo Fly Test or JACO results as the optotype. Results: Of the 19 patients, 13 (68.4%) had suppression before occlusion, eight (42.1%) when the highest VA was achieved, five (26.3%) during tapering, and none at the final visit. Of the 13 patients with suppression before occlusion, 10 (76.9%) showed further improvement in stereoacuity when suppression disappeared, and nine had foveal stereopsis of 60 arcseconds. A significant association was confirmed between foveal stereopsis and suppression when the highest VA was achieved and during the tapering period (P<0.05, Fisher's exact test). Conclusion: Suppression was observed even when the VA in amblyopic eyes reached the highest score. By gradually decreasing the duration of occlusion, suppression was eliminated, leading to the acquisition of foveal stereopsis.

Measurement of Fixational Eye Movements With the Head-Mounted Perimeter Imo.

Purpose: Although visual field testing is conducted with the subject gazing at a fixation target, constant minute eye movements, called fixational eye movements, do occur during fixation. We examined dynamic changes in fixational eye movements associated with stimulus presentation during visual field testing. Methods: We used the head-mounted perimeter imo, which is capable of measurement under binocular conditions, with the frame rate of its fixation monitoring camera improved to 300 Hz, to assess fixational eye movements in 18 healthy individuals. We measured changes in fixational eye movements during testing under monocular and binocular conditions and analyzed these changes based on the bivariate contour ellipse area (BCEA). We also assessed the changes in the horizontal and vertical microsaccade rates separately. Results: Both the BCEA and horizontal microsaccade rates were higher at 400 to 600 msec after stimulus presentation than during stimulus presentation (P < 0.01). Additionally, the BCEA and vertical microsaccade rates were significantly lower in the binocular condition than in the monocular condition (P < 0.01 and P < 0.05, respectively). We did not observe a significant correlation between the test locations and microsaccade direction during visual field testing. Conclusions: Fixational eye movements, especially vertical microsaccade rates, were lower in the binocular condition than in the monocular condition. Visual field testing under binocular conditions is a useful method for suppressing fixational eye movements and stabilizing the fixation during testing and may improve the reliability of the test results. Translational Relevance: Visual field testing under binocular conditions can make the fixation more stable during the testing compared with monocular conditions.

Effects of orthoptic training for residual diplopia after surgical repair of blowout fractures.

PURPOSE: To investigate the effects of orthoptic training for residual diplopia after blowout fracture (BOF) surgery. METHODS: We retrospectively reviewed the medical records of 14 (average age, 22.9 ± 13.1 years) patients with residual diplopia, who had undergone orthoptic training after BOF surgery at the Department of Ophthalmology, Kindai University Hospital, between August 2013 and September 2019. The orthoptic training included exercises for eye movement, convergence, and fusional area expansion. We assessed the training effects by scoring patients' Hess screen (Hess) test results and fields of binocular single vision (BSV). The scores obtained before/after surgery and after training were compared. We also investigated the factors that influenced patients' BSV scores after training. p < 0.05 was considered statistically significant. RESULTS: The respective pre- and postoperative and after-training average scores were 7.0 ± 5.3, 5.4 ± 4.3, and 2.5 ± 3.2 points for Hess and 50.0 ± 41.3, 48.2 ± 35.9, and 89.4 ± 14.0 points for BSV. Neither Hess nor BSV score showed a significant difference before and after surgery (p > 0.05, the Steel-Dwass test). Compared to the postoperative (i.e., before training) scores, both Hess and BSV scores significantly improved after training (p < 0.05 for Hess, p < 0.01 for BSV; the Steel-Dwass test). CONCLUSION: Orthoptic training appeared effective in resolving residual diplopia after BOF surgery by improving patients' ocular motility and expanding the BSV field.

Efficacies of preoperative prism adaptation test and monocular occlusion for detecting the maximum angle of deviation in intermittent exotropia.

BACKGROUND: The efficacies of prism adaptation test (PAT) and monocular occlusion (MO) and their optimal test durations to detect the maximum angles of deviation at near and distance in eyes with intermittent exotropia (IXT) were assessed and compared. METHODS: We retrospectively reviewed the medical records of 72 patients with IXT. All the patients had undergone the initial strabismus surgery between April 2015 and October 2018 and had been preoperatively tested by both PAT and MO performed on different days for 30 and 60 min. Near and distance deviations after 30 and 60 min of PAT and MO were compared to their baseline measurements obtained immediately after prism wear and before occlusion by alternate prism cover test. The near/distance measurements and required test duration to reveal the maximum deviation angle were also compared between PAT and MO. RESULTS: Compared with the baseline, the near deviation by PAT significantly increased after 30 (P < 0.05) and 60 (P < 0.01) minutes but not the distance deviation. However, the increase after 30 min was not significant. By MO, neither near nor distance deviation showed a significant difference from the baseline after 30 and 60 min. PAT showed a significantly larger near deviation than MO at 30 and 60 min, but a larger distance deviation by PAT was only observed at 30 min. CONCLUSIONS: In patients with basic and convergence insufficiency types of IXT, a 30-minute PAT appears to be more effective than MO in revealing the maximum angle of deviation before strabismus surgery.

Utility of CLOCK CHART binocular edition for self-checking the binocular visual field in patients with glaucoma.

BACKGROUND/AIMS: Car accidents caused by drivers unaware of their visual field (VF) defects under binocular vision have become an issue. We developed a simple self-check chart (CLOCK CHART binocular edition (CCBE)) to help patients with glaucoma recognise their abnormalities in the binocular VF and evaluated its usefulness. METHODS: The chart has four targets displayed at 10°, 15°, 20° and 25° eccentricities. The examinee gradually rotates the chart 360° clockwise. At every 30°, the examinee confirms the fixation and indicates if all four targets can be seen. This study enrolled 88 eyes of 44 patients with glaucoma (mean age, 64.4±13.1 years) and 64 eyes of 32 visually normal individuals (mean age, 32.0±8.4 years). Except the CCBE test, static VF testing using the Humphrey field analyser (HFA) Swedish Interactive Threshold Algorithm-Standard 30-2 and binocular Esterman programmes was also performed for the subjects with glaucoma. RESULTS: VF abnormality was defined as two or more contiguous points with a sensitivity of <10 dB within the central 30°. The CCBE test had sensitivities of 85% and 82% with respect to the HFA and Esterman results, respectively. We also used the British VF standards for Group 1 (car/motorcycle) drivers, and a sensitivity of 88% was obtained for the CCBE. The chart had a specificity of 100% for the visually normal subjects. CONCLUSION: The CCBE test enables drivers with glaucoma to notice their VF abnormalities under binocular condition. The application of this simple self-check method appears promising for occasions such as driver licensing.

Optic nerve tissue displacement during mild intraocular pressure elevation: its relationship to central corneal thickness and corneal hysteresis.

PURPOSE: To determine the extent to which (1) optic nerve tissue is displaced following mild acute elevation of intraocular pressure, and (2) clinically accessible measures at the anterior eye can be used as a surrogate for such displacements. METHODS: We imaged the optic disc of 21 healthy subjects before and after intraocular pressure (IOP) elevation of ~10 mmHg delivered by ophthalmodynamometry. Steady-state tissue displacement during IOP elevation was assessed axially from OCT data, and laterally from SLO data. Recovery from IOP elevation was assessed by tracking a single vertical B-scan through the cup centre. Anatomical structures were demarcated by three masked clinicians to determine lateral shifts for temporal cup edge and central disc vessels, and axial shifts of disc surface and anterior lamina cribrosa. Spatial maps of deformation were constructed within the demarcated cup and disc to assess within-tissue displacement. Measured displacements were correlated with corneal hysteresis, corneal thickness, and IOP. RESULTS: The temporal cup edge moved more temporally with higher baseline IOP (R2  = 0.33, p = 0.006) and with lesser elevation of IOP (R2  = 0.43, p = 0.001); it moved more superiorly for thinner corneas (R2  = 0.35, p = 0.007). Thinner corneas also produced less within-cup deformation, relative to that of the disc (R2  = 0.39, p = 0.004). Axial displacement of the lamina and lateral displacement of vessels were often substantial (lamina 20 ± 15 µm, range 1-60 µm; vessels 37 ± 25 µm, range 2-102 µm) but did not correlate with measured parameters. Recovery from IOP elevation did not take more than 300-400 ms in any subject. CONCLUSIONS: Mild acute elevation of IOP produces large and rapidly reversible shifts in optic nerve tissue in young, healthy eyes. The resulting degree, direction and spatial distribution of cup movement are associated with IOP status and corneal thickness, but not corneal hysteresis.

Role of fusional convergence amplitude in postoperative phoria maintenance in children with intermittent exotropia.

PURPOSE: To examine the role of fusional convergence amplitude in postoperative phoria maintenance in childhood intermittent exotropia [X(T)]. METHODS: The medical records of 29 children aged 15 years or younger (mean age, 10.8 ± 2.4 years) and treated with monocular recession-resection for X(T) were reviewed retrospectively. The patients' fusional convergence amplitude (break point/total amplitudes), physiologic diplopia, and phoria maintenance (presence/absence of phoria maintenance and ability to maintain phoria) were assessed. The presence of phoria maintenance was confirmed by a cover test, and the ability to maintain phoria was quantified using the Bagolini red filter bar. Correlations of the amplitude size with the presence and ability of phoria maintenance were investigated. RESULTS: A significant correlation was seen between fusional amplitude (break point/total) and ability to maintain phoria at near and at far (break point: P < .05 at near/P < .01 at far; total: P < .05 at near/far). Neither the break point amplitude nor the total amplitude significantly differed between the patients with phoria maintenance and those without it (break point: P = .71 at near, P = .29 at far; total: P = .98 at near, P = .85 at far). Phoria maintenance correlated with the suppression of physiologic diplopia during phoria (P < .01). The deviation angle did not significantly correlate with fusional amplitude either at near (P = .58) or at far (P = .27). CONCLUSIONS: In childhood X(T), fusional amplitude plays a role in enforcing the patient's ability to maintain phoria. However, sufficient fusional amplitude does not guarantee fully functioning fusion if suppression is present during phoria.

Distribution and Progression of Visual Field Defects With Binocular Vision in Glaucoma.

PURPOSE: To evaluate the distribution and progression of glaucomatous visual field (VF) defects with binocular vision. PATIENTS AND METHODS: Subjects were 167 patients (average age, 67±10.7 y) with glaucoma who received the Humphrey 24-2 VF test (SITA-Standard) for the 2 eyes. Using the Best Location Algorithm, patient's binocular integrated VF (IVF) was calculated from their Humphrey 24-2 results. Of 167, 77 subjects (average age, 68±11.0 y) also underwent monocular/binocular Humphrey Esterman tests. Patient's stage of glaucomatous VF loss was classified by the Esterman Disability Score for each test, and the distribution and progression of the defects with binocular vision was evaluated for each stage. The frequencies of the defects in the upper and lower halves of the VF were also investigated. RESULTS: With the IVF, the glaucomatous VF defects were most frequently found around the Mariotte blind spots and the Bjerrum areas and extended to the periphery. With the binocular Humphrey Esterman VF, the defects were most frequently found around the bitemporal and Bjerrum areas. The IVF results showed 31%, 49%, and 20% of the patients with the earliest glaucoma having defects in the upper, lower, and both halves of the VF, respectively. CONCLUSIONS: Glaucomatous VF defects with binocular vision were frequently found at the Mariotte blind spots in the central VF and around the bitemporal areas in the periphery. They appeared to have distributions and progression different from those of the defects with monocular vision previously reported.

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.

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 mm cube scan (3D OCT-2000, Topcon). The coefficient of determination (r) 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 r (linear) and R (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.

Influence of Test Distance on Stereoacuity in Intermittent Exotropia.

AIMS: To investigate influence of test distance on stereoacuity in intermittent exotropia (X[T]) using the same test conditions for both near and far distances. METHODS: Subjects were 38 consecutive patients with X(T). All the patients were between ages 6 and 15 years and had decimal visual acuity of 1.0 or better. Another inclusion criterion was presence of phoric condition at near and far distances. Stereoacuity was measured at a near distance of 40 cm and at a far distance of 5 m. The following test conditions were used for both test distances: separation of the two eyes using polarized glasses, and a target with a random dot pattern. All the stereograms had the same subtended angle of 2.5º, and binocular disparity of 480, 240, 120, and 60 arcsec. We used two stereogram types with crossed and uncrossed disparities. RESULTS: Far stereoacuity of 38 subjects measured with the crossed disparity was significantly worse than near stereoacuity (P<0.05, Wilcoxon signed-ranks test), although 30 (78.9%) of the 38 subjects showed no differences in stereopsis between the near and far distances. Far stereoacuity of 38 cases measured with the uncrossed disparity was significantly worse than at near (P<0.05, Wilcoxon signed-ranks test), although 20 (52.6%) of the 38 subjects showed no differences between stereoacuity at near and far. In comparison of stereoacuity with crossed disparity and uncrossed disparity, stereoacuity with crossed disparity was significantly better than that with uncrossed disparity both at near and far (P<0.05, Wilcoxon signed-ranks test). CONCLUSIONS: Stereoacuity in X(T) was different according to test distance when measured controlling subtended angle of stereogram at both distances. Far stereoacuity was significantly worse than near stereoacuity when measured using test targets with both crossed and uncrossed disparities. Additionally, stereoacuity measured with crossed disparity was better than that with uncrossed disparity at both distances.

Automatic identification of the temporal retinal nerve fiber raphe from macular cube data.

We evaluated several approaches for automatic location of the temporal nerve fiber raphe from standard macular cubes acquired on a Heidelberg Spectralis OCT. Macular cubes with B-scan separation of 96-122 µm were acquired from 15 healthy participants, and "high density" cubes with scan separation of 11 µm were acquired from the same eyes. These latter scans were assigned to experienced graders for subjective location of the raphe, providing the ground truth by which to compare methods operating on the lower density data. A variety of OCT scan parameters and image processing strategies were trialed. Vertically oriented scans, purposeful misalignment of the pupil to avoid reflective artifacts, and the use of intensity as opposed to thickness of the nerve fiber layer were all critical to minimize error. The best performing approach "cFan" involved projection of a fan of lines from each of several locations across the foveal pit; in each fan the line of least average intensity was identified. The centroid of the crossing points of these lines provided the raphe orientation with an average error of 1.5° (max = 4.1°) relative to the human graders. The disc-fovea-raphe angle was 172.4 ± 2.3° (range = 168.5-176.2°), which agrees well with other published estimates.

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.

CLOCK CHART(®): a novel multi-stimulus self-check visual field screener.

PURPOSE: CLOCK CHART(®) is a multi-stimulus-type self-check visual field screening sheet developed by our group. The test chart is rotated during the examination, and the visual field abnormalities are pointed out by the patients themselves. In this study, we evaluated the clinical usefulness of this chart in patients with glaucoma. METHODS: We studied 114 eyes of 114 glaucoma patients (average age 60.0 ± 11.1 years) and 45 eyes of 45 normal individuals (average age 45.0 ± 16.4 years) using CLOCK CHART(®). The static visual fields were obtained using the Octopus 101 G2 program and classified using the Aulhorn classification as modified by Greve (stages 0-I to IV) and by mean defect (MD; early <6 dB; moderate 6 ≤ MD ≤12 dB; severe >12 dB).The sensitivity and specificity of CLOCK CHART(®) for detecting visual field abnormalities were evaluated within the entire 25° field and at the 5°, 10°, 15°, 20°, and 25° eccentricity zones. The visual field agreement between the results of CLOCK CHART(®) and the static visual fields were also evaluated. RESULTS: In glaucomatous eyes, the sensitivity of CLOCK CHART(®) was 85, 93, and 100 % for Greve stages I, II and III-VI, respectively, and 87, 93, and 97 % for the MD value in early, moderate, and severe eyes, respectively. The agreement of the visual field defect area in CLOCK CHART(®) with the static fields was 85 and 100 % with Greve stages 0-I to I and II-VI, respectively, and 91, 96, and 96 % in early, moderate and severe glaucomatous eyes according to MD, respectively. The specificity of CLOCK CHART(®) was 89 %. CONCLUSION: CLOCK CHART(®) is a simple and reliable self-check screening chart for detecting visual field abnormalities in patients with glaucoma.

Optical coherence tomographic findings at the fixation point in a case of bilateral congenital macular coloboma.

BACKGROUND: Congenital macular coloboma is a rare ocular disease that consists of atrophic lesions in the macula with well-circumscribed borders. We report the findings of spectral domain optical coherence tomography (SD-OCT) at the fixation point in a case of bilateral macular coloboma. CASE REPORT: The subject is a 4-year-old boy. He visited our hospital at age 1 year and 4 months for the evaluation of strabismus. The fundus examination of both eyes showed round-shaped sharply-demarcated atrophic lesions involving the macula with large choroidal vessels and bared sclera at the base. Immunologic tests including toxoplasmosis, rubella, varicella, herpes virus, and human T-cell leukemia virus were all negative. At age 4 years and 1 month, cycloplegic refraction showed insignificant refractive errors and his best corrected visual acuity was 0.6 bilaterally. The SD-OCT showed a crater-like depression accompanying atrophic neurosensory retina, and the absence of retinal pigment epithelium and choroid. Examination of the fixation behavior by visuscope showed steady fixation with an area 0.5° nasal to the nasal edge of the atrophic lesion bilaterally. The SD-OCT findings at fixation area showed remaining normal retinal structures involving inner segment-outer segment (IS/OS) junction line. CONCLUSION: The findings of SD-OCT have been shown to be useful in the diagnosis of macular coloboma. In the fixation point, the structure of retina and choroid were well preserved.

Structure-function mapping: variability and conviction in tracing retinal nerve fiber bundles and comparison to a computational model.

PURPOSE: We evaluated variability and conviction in tracing paths of retinal nerve fiber bundles (RNFBs) in retinal images, and compared traced paths to a computational model that produces anatomically-customized structure-function maps. METHODS: Ten retinal images were overlaid with 24-2 visual field locations. Eight clinicians and 6 naïve observers traced RNFBs from each location to the optic nerve head (ONH), recording their best estimate and certain range of insertion. Three clinicians and 2 naïve observers traced RNFBs in 3 images, 3 times, 7 to 19 days apart. The model predicted 10° ONH sectors relating to each location. Variability and repeatability in best estimates, certain range width, and differences between best estimates and model-predictions were evaluated. RESULTS: Median between-observer variability in best estimates was 27° (interquartile range [IQR] 20°-38°) for clinicians and 33° (IQR 22°-50°) for naïve observers. Median certain range width was 30° (IQR 14°-45°) for clinicians and 75° (IQR 45°-180°) for naïve observers. Median repeatability was 10° (IQR 5°-20°) for clinicians and 15° (IQR 10°-29°) for naïve observers. All measures were worse further from the ONH. Systematic differences between model predictions and best estimates were negligible; median absolute differences were 17° (IQR 9°-30°) for clinicians and 20° (IQR 10°-36°) for naïve observers. Larger departures from the model coincided with greater variability in tracing. CONCLUSIONS: Concordance between the model and RNFB tracing was good, and greatest where tracing variability was lowest. When RNFB tracing is used for structure-function mapping, variability should be considered.