Atsushi Mizota

Anisometropic amblyopia is decreased visual acuity in one eye, and treatment consists of wearing complete corrective spectacles. Aniseikonia occurs with complete correction of anisometropia using spectacles. Aniseikonia has been ignored when treating pediatric anisometropic amblyopia because of the prevailing belief that anisometropic symptoms are suppressed by adaptation. However, the conventional direct comparison method for evaluating aniseikonia significantly underestimates the degree of aniseikonia. This study investigated whether the adaptation occurs due to long-term anisometropic amblyopia treatment in patients who have had successful amblyopia treatment using a spatial aniseikonia test with high accuracy and repeatability compared with the conventional direct comparison method. The amount of aniseikonia was not significantly different between the patients with successful amblyopia treatment and individuals with anisometropia without a history of amblyopia. In both groups, the aniseikonia per 1.00 D of anisometropia and the aniseikonia per 1.00 mm of aniso-axial length were comparable. The repeatability of the amount of aniseikonia using the spatial aniseikonia test did not differ significantly between the two groups, indicating a high degree of agreement. These findings suggest that aniseikonia is not adapted to amblyopia treatment and that aniseikonia increases as the difference between spherical equivalent and axial length increases.

Purpose: The purpose of this study was to determine the effect of brilliant blue G (BBG) staining of the inner limiting membrane (ILM) on macular function. Method: Fourteen eyes of 14 patients consisting of 9 men and 5 women who underwent vitreous surgery with ILM peeling were studied. The mean age of the patients was 68.8 ± 9.14 years. Three eyes had a macular hole and eleven eyes had an epiretinal membrane. The ILM was made more visible by spraying 0.25% BBG into the vitreous cavity. The macular function was assessed by recording intraoperative focal macular electroretinograms (iFMERGs) before and after the intravitreal spraying of the BBG dye. The iFMERGs were recorded three times after core vitrectomy. The first recording was performed before the BBG injection (Phase 1, baseline), the second recording was performed after the spraying of the BBG and washing out the excess BBG (Phase 2), and the third recording was performed after the ILM peeling (Phase 3). All recordings were performed after 5 min of light-adaptation and stabilization of the intraocular conditions. The iFMERGs were recorded twice at each phase. The implicit times and amplitudes of the a- and b-wave, the PhNR, and the d-wave were measured. Wilcoxon signed-rank test were used to determine the significance of differences of the findings at Phase 2 vs. Phase 1 and Phase 3 vs. Phase 1. A p value < 0.05 was taken to be statistically significant. Results: The average implicit times of the a-wave, b-wave, PhNR, and d-wave were not significantly different in Phase 1, 2, and 3. The average a-wave, b-wave, PhNR, and d-wave amplitudes at Phase 1 did not differ significantly from that at Phase 2 and at Phase 3. Conclusions: The results indicated that the intravitreal injection of BBG does not alter the physiology of the macula, and we conclude that BBG is safe. We also conclude that iFMERGs can be used to monitor the macular function safely during intraocular surgery.

Eye checkups have become increasingly important to maintain good vision and quality of life. As the population requiring eye checkups increases, so does the clinical work burden of clinicians. An automatic screening algorithm to reduce the clinicians’ workload is necessary. Machine learning (ML) has recently become one of the chief techniques for automated image recognition and is a helpful tool for identifying ocular diseases. However, the accuracy of ML models is lower in a clinical setting than in the laboratory. The performance of ML models depends on the training dataset. Eye checkups often prioritize speed and minimize image processing. Data distribution differs from the training dataset and, consequently, decreases prediction performance. The study aim was to investigate an ML model to screen for retinal diseases from low-quality optical coherence tomography (OCT) images captured during actual eye chechups to prevent a dataset shift. The ensemble model with convolutional neural networks (CNNs) and random forest models showed high screening performance in the single-shot OCT images captured during the actual eye checkups. Our study indicates the strong potential of the ensemble model combining the CNN and random forest models in accurately predicting abnormalities during eye checkups.

Vitreous temperature has been reported to vary during intraocular surgery. We measured the temperature at three intraocular sites, just posterior to the crystalline lens (BL), mid-vitreous (MV), and just anterior to the optic disc (OD), and investigated temperature changes before and after different types of surgical procedures in 78 eyes. The mean temperature at the beginning was 30.1 ± 1.70 °C in the anterior chamber, 32.4 ± 1.41 °C at the BL, 33.8 ± 0.95 °C at the MV, and 34.7 ± 0.95 °C at the OD. It was lowest at the BL, and highest at the OD. The mean temperature after cataract surgery was slightly lower especially at an anterior location. Thus, the temperature gradient became slightly flatter. The mean temperature after core vitrectomy was even lower at all sites and a gradient of the temperature was not present. The mean temperature after membrane peeling was significantly higher than that after core vitrectomy, and there was no gradient. The mean temperature after fluid/air exchange was lower at the BL and higher at the MV and at the OD. Thus, a gradient of higher temperatures at the OD appeared. The intraocular temperature distribution is different depending on the surgical procedure which can then change the temperature gradient. The temperature changes at the different intraocular sites and the gradients should be further investigated because they may affect the physiology of the retina and the recovery process.

Background: Visualization of aqueous humor flow in the human eye is difficult because gadolinium, a magnetic resonance imaging (MRI) contrast agent, does not readily cross the blood-retinal and blood-aqueous barriers of capillaries that supply water to the eye. The proton ( ¹ H) of oxygen-17 water (H ₂ ¹⁷ O) has a very short transverse relaxation time (T ₂ ), and the T2-weighted (T2W) ¹ H-MRI signal intensity of a region with H ₂ ¹⁷ O is lower than that with only H ₂ ¹⁶ O. Purpose: To observe the distribution of H ₂ ¹⁷ O in the human eye, and the flow into and out of the anterior chamber of H ₂ ¹⁷ O, using dynamic T2W ¹ H-MRI. Materials and Methods: Seven ophthalmologically normal adult volunteers under 40 years old participated in this study. During dynamic imaging, the subject self-administered 10 mol% H ₂ ¹⁷ O saline (0.92–1.37 mL) to their right eye for 1 min. Time-series images were created by subtracting the image before the eye drops from each of the images obtained after the eye drops. The “normalized signal intensity of the right anterior chamber” (rAC) in each image was obtained by dividing the signal intensity of the right anterior chamber region-of-interest by that of the left. Changes in transverse relaxation rate and H ₂ ¹⁷ O concentration ( P _{O 17} ) were calculated from the rAC. The inflow and outflow constants of H ₂ ¹⁷ O in the right anterior chamber were also determined. Results: Decreased signal intensity after the H ₂ ¹⁷ O eye drops was observed in the anterior and posterior chambers, but not in the vitreous body. The rAC signal intensity decreased after the eye drops, and then recovered to close to rAC(0) at 40 min. The inflow and outflow constants were 0.53 ± 0.19 and 0.055 ± 0.019 min ^-1 , respectively, and the peak value of P _{O 17} was 0.19 ± 0.04% (mean ± SD). Conclusion: H ₂ ¹⁷ O saline eye drops distributed in the human anterior and posterior chambers. Further, the eye drops smoothly flowed into, and slowly out of, the anterior chamber. Summary: O-17 water dropped into human eyes as a T2-weighted MRI contrast agent was distributed in the anterior and posterior chambers, with smooth flow into, and slow outflow from, the anterior chamber. Key findings: In seven healthy volunteers, dynamic T2-weighted ¹ H-MRI showed that the signal intensity in the anterior chamber decreased smoothly after H ₂ ¹⁷ O eye drops and then slowly recovered, reaching a value close to that observed before the eye drops, after 40 minutes, with inflow and outflow constants of H ₂ ¹⁷ O of 0.53 ± 0.19 min ^-1 and 0.055 ± 0.019 min ^-1 , respectively. The signal changes were limited to the anterior and posterior chambers and were not observed in the vitreous body.

Peripherin-2 (PRPH2) is one of the causative genes of inherited retinal dystrophy. While the gene is relatively common in Caucasians, reports from Asian ethnicities are limited. In the present study, we report 40 Japanese patients from 30 families with PRPH2-associated retinal dystrophy. We identified 17 distinct pathogenic or likely pathogenic variants using next-generation sequencing. Variants p.R142W and p.V200E were relatively common in the cohort. The age of onset was generally in the 40’s; however, some patients had earlier onset (age: 5 years). Visual acuity of the patients ranged from hand motion to 1.5 (Snellen equivalent 20/13). The patients showed variable phenotypes such as retinitis pigmentosa, cone-rod dystrophy, and macular dystrophy. Additionally, intrafamilial phenotypic variability was observed. Choroidal neovascularization was observed in three eyes of two patients with retinitis pigmentosa. The results demonstrate the genotypic and phenotypic variations of the disease in the Asian cohort.

The temperature of the vitreous has been reported to vary during cataract and vitreous surgery. We measured intraocular temperature at four intraocular sites; the anterior chamber (AC), just behind the crystalline lens, mid-vitreous, and just anterior to the optic disc (OD) at the beginning of vitrectomy with a thermoprobe in 48 eyes. The temperatures were compared in three groups; eyes that underwent vitrectomy for the first time (Group V, n = 30), eyes that had previous vitrectomy and the vitreous cavity had been filled with balanced salt solution (BSS; Group A, n = 12), and eyes that had previous vitrectomy and the vitreous cavity was filled with silicone oil (Group S, n = 6). There was a gradient in the temperature in all groups, i.e., it was lowest in the AC, and it increased at points closer to the retina. The intraocular temperature was significantly correlated with the type of fluid in the vitreous cavity. The mean intraocular temperatures were not significantly different in Groups V and A, but they were significantly higher in Group S. Clinicians should be aware of the differences in the temperature at the different intraocular sites because the temperatures may affect the physiology of the retina and the recovery process.

Purpose: The purpose of this study was to develop a technique combining video oculography (VOG) with single shot multibox detector (SSD) to accurately and quantitatively examine eye movements. Methods: Eleven healthy volunteers (21.3 ± 0.9 years) participated in this study. Eye movements were recorded while tracking a target using a custom-made eye tracker. The subjects were asked to fixate their focus on the nose of the rabbit-like target (visual angle was 0.1°), which was manually moved to a distance of 1 meter by the examiner during the eye movement test. The test produced 500 images from the VOG external camera and these images were divided into 3 groups (300, 100, and 100) for training, verification, and testing. The performance of the SSD was evaluated with 75% average precision (AP ₇₅ ), and the relationship between the location of the fixated target (calculated by the SSD) and the positions of both eyes (recorded by the VOG) was analyzed. Results: The AP ₇₅ of the SSD on one class of targets was 97.7%. The horizontal and vertical target locations significantly and positively correlated with the horizontal and vertical both eye positions ( adjusted R ² ≥ 0.955, P < 0.001). Conclusions: Our findings suggest that VOG with SSD is suitable for the evaluation of eye version movements in standard clinical assessments. Translational Relevance: The combination of VOG and SSD can be used to evaluate the SPEM, and this method can be translated into clinical settings without changing the testing methods.

Purpose. Trichotillomania is a behavioral and mental disorder and is characterized by a recurring habit of pulling out one’s hair. The differential diagnosis between trichotillomania and other hair loss conditions such as alopecia areata is difficult for ophthalmologists. We report a rare case of bilateral trichotillomania of the eyelashes that was triggered by anxiety about nocturnal enuresis. Case Report. A healthy 9-year-old Japanese boy presented with a bilateral loss of his eyelashes. His parents had believed that his loss of eyelashes was due to alopecia, an autoimmune disorder that results in hair loss, of the eyelashes. Our initial examination revealed that he had suffered from nightly nocturnal enuresis from childhood and was scheduled to go on a school trip the following month. He feared that his school mates might find out about his enuresis, and he said that the anxiety was the cause of the eyelash trichotillomania. The trichotillomania was resolved by discussion among the student, his family, teacher, and school counselor. Conclusion. To the best of our knowledge, this is the first report of eyelash trichotillomania caused by anxiety about nocturnal enuresis. Ophthalmologists should be aware that a patient without eyelashes may not be due to alopecia but some anxiety-producing events. In addition, discussion of the anxiety-producing factor among the parents, teacher, and school counselors can resolve the trichotillomania.

To evaluate the retinal function before and soon after an intravitreal injection of an anti-vascular endothelial growth factor (anti-VEGF) agents. Seventy-nine eyes of 79 patients that were treated by an intravitreal injection of an anti-VEGF agent for age-related macular degeneration (AMD), diabetic macular edema (DME), or retinal vein occlusion (RVO) with macular edema (ME) were studied. The RETeval® system was used to record 28 Hz flicker electroretinograms (ERGs) from the injected and non-injected eyes before (Phase 1, P1), within 2 h after the injection (P2), and 2 to 24 h after the injection (P3). Patients were grouped by disease or by the injected agent and compared. The significance of the changes in the implicit times and amplitudes was determined by t tests. The amplitudes were not significantly different at the three phases. The implicit time of the injected eye was 31.2 ± 3.2 msec at P1, and it was not significantly different at P2 (31.7 ± 3.1 msec) but it was significantly longer at P3 (32.2 ± 3.3 msec, P < 0.01, ANOVA for both). The implicit time in the non-injected fellow eye was 30.5 ± 3.3 msec at P1, and it was significantly longer at P2 (31.1 ± 3.2 msec) and phase 3 (31.3 ± 3.4 msec, P < 0.01, ANOVA for both). The results indicate that an intravitreal anti-VEGF injection will increase the implicit times not only in the injected eye but also in the non-injected eye soon after the intravitreal injection.